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项目的简单核心中轴线
我使用的eclips开发工具,和主播的操作可能存在不同
环境:
要求:
创建一个存放书籍数据的数据库表
CREATE DATABASE `ssmbuild`; USE `ssmbuild`; DROP TABLE IF EXISTS `books`; CREATE TABLE `books` ( `bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id', `bookName` VARCHAR(100) NOT NULL COMMENT '书名', `bookCounts` INT(11) NOT NULL COMMENT '数量', `detail` VARCHAR(200) NOT NULL COMMENT '描述', KEY `bookID` (`bookID`) ) ENGINE=INNODB DEFAULT CHARSET=utf8 INSERT INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES (1,'Java',1,'从入门到放弃'), (2,'MySQL',10,'从删库到跑路'), (3,'Linux',5,'从进门到进牢');
程序员90%的业务就是CRUD(增删改查)
Maven基本项目里至少要完成两件事情,依赖和静态资源导出问题。
依赖:
1、新建一Maven项目!ssmbuild , 添加web的支持
eclipse,创建Maven-web项目
2、导入相关的pom依赖!
<dependencies> <!--Junit--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <!--数据库驱动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 数据库连接池 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!--Servlet - JSP --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!--Mybatis--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.2</version> </dependency> <!--Spring--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.9.RELEASE</version> </dependency> </dependencies>
3、Maven资源过滤设置
<build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> </resources> </build>
4、建立基本结构和配置框架!
com.kuang.pojo (数据对象原型)
com.kuang.dao (连接数据层)
com.kuang.service (业务逻辑层)
com.kuang.controller (接收前段业务层)
mybatis-config.xml(mybatis配置文件)
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> </configuration>
applicationContext.xml(spring配置文件)
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> </beans>
1、数据库配置文件 database.properties
jdbc.driver=com.mysql.jdbc.Driver # 如果使用的是MySQL8.0+, 需要增加一个时区的配置;&serverTimezone=Asia/Shanghai jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8 jdbc.username=root jdbc.password=123456
这里发现eclipse的.properties文件中文出现乱码问题解决方法—11.1
2、IDEA关联数据库
(我使用的是eclipse工具,没找到关联数据库的方法,以后再研究)
3、编写MyBatis的核心配置文件
mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!-- 添加日志 --> <settings> <setting name="logImpl" value="STDOUT_LOGGING"/> </settings> <!-- 配置数据源,交给Spring去做 --> <typeAliases> <package name="com.kuang.pojo"/> </typeAliases> <mappers> <mapper resource="com/kuang/dao/BookMapper.xml"/> </mappers> </configuration>
老师视频中使用的是:<mapper class="com.kuang.dao.BookMapper.xml"/>
但是我使用class搜索不到,所以使用resource
4、编写数据库对应的实体类 com.kuang.pojo.Books
lombok依赖
但是我使用eclips工具,lombok直接用依赖无法使用,以后再研究
<!-- Lombok --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombpk</artifactId> <version>1.16.10</version> </dependency>
package com.kuang.pojo; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; @Data @AllArgsConstructor @NoArgsConstructor public class Books { private int bookID; private String bookName; private int bookCounts; private String detail; }
5、编写Dao层的 Mapper接口!
package com.kuang.dao; import com.kuang.pojo.Books; import java.util.List; public interface BookMapper { //增加一个Book int addBook(Books book); //根据id删除一个Book int deleteBookById(@Param("bookId") int id); //更新Book int updateBook(Books books); //根据id查询,返回一个Book Books queryBookById(@Param("bookId") int id); //查询全部Book,返回list集合 List<Books> queryAllBook(); }
6、编写接口对应的 Mapper.xml 文件。需要导入MyBatis的包;
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.kuang.dao.BookMapper"> <insert id="addBook" parameterType="Books"> insert into ssmbuild.books (bookName,bookCounts,detail) values(#{bookName},#{bookCounts},#{detail}); </insert> <delete id="deleteBookById" parameterType="int"> delete from ssmbuild.books where bookID=#{bookId}; </delete> <update id="updateBook" parameterType="Books"> update ssmbuild.books set bookName=#{bookName},bookCounts=#{bookCounts},detail=#{detail} where bookID=#{bookId}; </update> <select id="queryBookById" resultType="Books"> select * from ssmbuild.books where bookID=#{bookId}; </select> <select id="queryAllBook" resultType="Books"> select * from ssmbuild.books; </select> <!-- 输入完第一件事就是核心配置文件注册 --> </mapper>
7、编写Service业务层的接口和实现类
接口
package com.kuang.service; import java.util.List; import com.kuang.pojo.Books; public interface BookService { //增加一个Book int addBook(Books book); //根据id删除一个Book int deleteBookById(int id); //更新Book int updateBook(Books books); //根据id查询,返回一个Book Books queryBookById(int id); //查询全部Book,返回list集合 List<Books> queryAllBook(); }
实现类
package com.kuang.service; import java.util.List; import com.kuang.dao.BookMapper; import com.kuang.pojo.Books; public class BookServiceImpl implements BookService { //service业务层调dao层:组合dao层 private BookMapper bookMapper; public void setBookMapper(BookMapper bookMapper) { this.bookMapper = bookMapper; } @Override public int addBook(Books book) { return bookMapper.addBook(book); } @Override public int deleteBookById(int id) { return bookMapper.deleteBookById(id); } @Override public int updateBook(Books books) { return bookMapper.updateBook(books); } @Override public Books queryBookById(int id) { return bookMapper.queryBookById(id); } @Override public List<Books> queryAllBook() { return bookMapper.queryAllBook(); } }
Mybatis层核心就是在写底层,建数据库、pojo数据实体类、dao层和service层的简单动作
1、配置Spring整合MyBatis,我们这里数据源使用c3p0连接池;
2、我们去编写Spring整合Mybatis的相关的配置文件;spring-dao.xml
数据库连接池有很多种
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd "> <!-- 1.关联数据库配置文件 --> <context:property-placeholder location="classpath:database.properties"/> <!-- 2.数据库连接池 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${jdbc.driver}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <!-- c3p0连接池的私有属性 --> <property name="maxPoolSize" value="30"/> <property name="minPoolSize" value="10"/> <!-- 关闭连接后不自动commit --> <property name="autoCommitOnClose" value="false"/> <!-- 获取连接超时时间 --> <property name="checkoutTimeout" value="10000"/> <!-- 当获取连接失败重试次数 --> <property name="acquireRetryAttempts" value="2"/> </bean> <!-- 3.配置SqlSessionFactory对象 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据库连接池 --> <property name="dataSource" ref="dataSource"/> <!-- 配置MyBaties全局配置文件:mybatis-config.xml --> <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean> <!-- 4.配置扫描Dao接口包,动态实现Dao接口注入到spring容器中 --> <!--解释 :https://www.cnblogs.com/jpfss/p/7799806.html--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 注入sqlSessionFactory --> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> <!-- 给出需要扫描Dao接口包 --> <property name="basePackage" value="com.kuang.dao"/> </bean> </beans>
3、Spring整合service层
spring-service.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- 可以通过import关联 <import resource="classpath:spring-dao.xml"/> 也可以在applicationContext.xml中全部import关联 --> <!-- 1.扫描service的包 --> <context:component-scan base-package="com.kuang.service" /> <!-- 2.将我们的所有业务类,BookServiceImpl注入到spring,可以通过配置,或者注解实现--> <bean id="BookServiceImpl" class="com.kuang.service.BookServiceImpl"> <property name="bookMapper" ref="bookMapper"/> </bean> <!-- 3.配置事务管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <!-- 注入数据库连接池数据源 --> <property name="dataSource" ref="dataSource" /> </bean> <!-- 再有的话就是4.aop事务支撑 --> </beans>
也可以通过注解注入到spring
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <import resource="classpath:spring-dao.xml"/> <import resource="classpath:spring-service.xml"/> </beans>
Spring层搞定!再次理解一下,Spring就是一个大杂烩,一个容器
1、web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://JAVA.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <!-- DispatchServlet --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <!--一定要注意:我们这里加载的是总的配置文件,之前被这里坑了!--> <param-value>classpath:spring-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 乱码过滤 --> <filter> <filter-name>encodingFilter</filter-name> <filter-class> org.springframework.web.filter.CharacterEncodingFilter </filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!--Session过期时间--> <session-config> <session-timeout>15</session-timeout> </session-config> </web-app>
2、spring-mvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd "> <!-- 1.注解驱动 --> <mvc:annotation-driven/> <!-- 2.静态资源过滤 --> <mvc:default-servlet-handler/> <!-- 3.扫描包:controller --> <context:component-scan base-package="com.kuang.controller"/> <!-- 4.视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans>
3、Spring配置整合文件,applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <import resource="classpath:spring-dao.xml"/> <import resource="classpath:spring-service.xml"/> <import resource="classpath:spring-mvc.xml"/> </beans>
两种获取方法都可以使用
<import resource="spring-dao.xml"/>
<import resource="spring-service.xml"/>
<import resource="spring-mvc.xml"/>
这些底层以后大部分业务都可以使用,最好保存下来
配置文件,暂时结束!Controller 和 视图层编写
1.1、com.kuang.controller.BookController 类编写 , 方法一:查询全部书籍
package com.kuang.controller; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import com.kuang.pojo.Books; import com.kuang.service.BookService; @Controller @RequestMapping("/book") public class BookController { //Controller 调 service层 @Autowired @Qualifier("BookServiceImpl") private BookService bookService; //查询全部的书籍,并且返回到一个书籍展示页面 @RequestMapping("/allBook") public String list(Model model) { List<Books> list = bookService.queryAllBook(); model.addAttribute("list", list); return "allbook"; } }
1.2、编写首页 index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>首页</title> </head> <body> <h3> <a href="${pageContext.request.contextPath}/book/allBook">进入书籍页面</a> </h3> </body> </html>
1.3、书籍列表页面 allbook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>书籍展示</title> </head> <body> <h1>书籍展示</h1> </body> </html>
第一次底层测试,发现报错
报错:问题 bean 不存在
分析步骤:
查看这个bean注入是否成功
Junit单元测试,看我们的代码是否能够查询出来结果
public class MyTest { @Test public void test() { ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); BookServiceImpl bookServiceImpl = (BookServiceImpl) context.getBean("BookServiceImpl"); for (Books books : bookServiceImpl.queryAllBook()) { System.out.println(books); } } }
通过查询可以获得结果,底层代码肯定没问题。
肯定是Spring出了问题
SpringMVC,整合的时候没电泳到我们的sevice层的bean
applicationContext.xml 有没有注入bean(已经整合)
web.xml中,也绑定过配置文件
发现问题,我们配置的是Spring-mvc.xml,这里面确实没有 service bean,所有报空指针异常
该为汇总的applicationContext.xml,就可以正常运行。
2.1、美化首页 index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>首页</title> <style> a{ text-decoration:none; color:black; font-size:18px; } h3{ width:180px; height:38px; margin:100px auto; text-align:center; line-height:38px; background:deepskyblue; border-radius:5px; } </style> </head> <body> <h3> <a href="${pageContext.request.contextPath}/book/allBook">点击进入列表页</a> </h3> </body> </html>
2.2、美化书籍展示界面 allBook.jsp
使用BootStrap美化界面,官网:https://www.bootcss.com/
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>书籍展示</title> <%-- BootStrap 美化界面 --%> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <%-- container一种格式边框 --%> <div class="container"> <%-- 清除浮动 --%> <div class="row clearfix"> <%-- 分割,将屏幕横向分成12份,md屏幕大小,12占满全部12份 --%> <div class="col-md-12 column"> <%-- 头部 --%> <div class="page-header"> <%-- small标签 --%> <h1> <small>书籍列表 ———— 显示所有书籍</small> </h1> </div> </div> </div> <div class="row clearfix"> <div class="col-md-12 column"> <table class="table table-hover table-striped"> <thead> <tr> <th>书籍编号</th> <th>书籍名称</th> <th>书籍数量</th> <th>书籍详情</th> </tr> </thead> <%-- 书籍从数据库中查询出来,从这个list中遍历出来:forEach(注意抬头引用) --%> <tbody> <%-- 获取数据 --%> <c:forEach var="book" items="${list}"> <tr> <td>${book.bookID}</td> <td>${book.bookName}</td> <td>${book.bookCounts}</td> <td>${book.detail}</td> </tr> </c:forEach> </tbody> </table> </div> </div> </div> </body> </html>
3.1、allBook.jsp 书籍展示界面添加功能: 新增书籍
<div class="row clearfix"> <div class="col-md-4 column"> <%-- toAddBook --%> <a href="${pageContext.request.contextPath}/book/toAddBook">新增书籍</a> </div> </div>
3.2、BookController 类编写方法:添加书籍
//跳转到增加书籍的页面 @RequestMapping("/toAddBook") public String toAddPaper() { return "addBook"; } //增加书籍的请求 @RequestMapping("/addBook") public String addPaper(Books books) { System.out.println("addBook=>"+books); bookService.addBook(books); return "redirect:/book/allBook";//重定向 }
3.3、添加书籍页面 addBook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>增加书籍</title> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container"> <div class="row clearfix"> <div class="col-md-12 column"> <div class="page-header"> <h1> <small>新增书籍</small> </h1> </div> </div> </div> <form action="${pageContext.request.contextPath}/book/addBook" method="post"> 书籍名称:<input type="text" name="bookName" required><br><br><br> 书籍数量:<input type="text" name="bookCounts" required><br><br><br> 书籍详情:<input type="text" name="detail" required><br><br><br> <input type="submit" value="添加"> </form> </div> </body> </html>
4.1、allbook.jsp 添加功能: 修改、删除
<td> <%-- 发送修改消息,并且发现修改对象的id,让修改的时候可以看到对象值 --%> <a href="${pageContext.request.contextPath}/book/toUpdate?id=${book.bookID}">修改</a> | <a href="${pageContext.request.contextPath}/book/deleteBook/${book.bookID}">删除</a> </td>
(老师使用
进行空格,但是我这程序只读取了字符串并未转换为空格,所以我没使用)
4.2、BookController 类编写方法三:修改书籍
//跳转到修改页面 @RequestMapping("/toUpdate") //获得对象的id,方便修改页面显示出对象的值。并使用model携带 public String toUpdatePaper(int id,Model model) { Books books = bookService.queryBookById(id); model.addAttribute("QBook",books); return "updateBook"; } //修改书籍的请求 @RequestMapping("/updateBook") public String UpdateBook(Books books) { System.out.println("UpdateBook=>"+books); bookService.updateBook(books); return "redirect:/book/allBook";//重定向 }
4.3、修改书籍页面 updateBook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>修改书籍</title> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container"> <div class="row clearfix"> <div class="col-md-12 column"> <div class="page-header"> <h1> <small>修改书籍</small> </h1> </div> </div> </div> <%-- 原来在没有bookID时,运行出现问题:提交修改的SQL请求时出现问题,提交成功,但是内容没有修改 --%> <%-- 初次考虑是提交事务问题,配置完毕后发现依旧失败 --%> <%-- 看一下SQL语句,能否执行成功:SQL执行失败,修改未完成,发现会ID默认提交为0,和实际参数不符,数据库也没有这个参数 --%> <%-- 修改:增加bookID语句,可以使用前段传递隐藏域 --%> <%-- <input type="hidden" name="bookID" value="${QBook.bookID}"> --%> <%-- 我觉得显示ID更合理,readonly不可修改的内容,并染色 --%> <form action="${pageContext.request.contextPath}/book/updateBook" method="post"> ID:<input type="text" name="bookID" value="${QBook.bookID}" style="background:#FFFF00" readonly><br><br><br> 书籍名称:<input type="text" name="bookName" value="${QBook.bookName}" required><br><br><br> 书籍数量:<input type="text" name="bookCounts" value="${QBook.bookCounts}" required><br><br><br> 书籍详情:<input type="text" name="detail" value="${QBook.detail}" required><br><br><br> <input type="submit" value="修改"> </form> </div> </body> </html>
修改功能程序出现的问题:
开始刚添加时由于ID不能修改,所以并未打算传输bookID,但是运行时出现了问题:提交修改的SQL请求时出现问题,提交成功,但是内容没有修改
初次考虑是提交事务问题,配置完毕后发现依旧失败
横切事务:
事务jar包
<dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.13</version> </dependency>
横切:
<!-- 配置事务通知 --> <tx:advice id="txAdvice" transaciton-manager="transactionManager"> <tx:attributes> <tx:method name="*" propagation="REQUIRED"/> </tx:attributes> </tx:advice> <!-- 配置事务切入 --> <aop:config> <aop:pointcut id="txPointCut" expression="execution(* com.kuang.dao.*.*(..))"/> <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/> </aop:config>
看一下SQL语句,能否执行成功:SQL执行失败,修改未完成,发现会ID默认提交为0,和实际参数不符,数据库也没有这个参数
修改:增加bookID语句,可以使用前段传递隐藏域
4.4、BookController - 类编写方法四:删除书籍
//删除书籍 //提交的id会转换为bookId,并且解析为int类型传到下面 @RequestMapping("/deleteBook/{bookId}") public String deleteBook(@PathVariable("bookId") int id) { bookService.deleteBookById(id); return "redirect:/book/allBook"; }
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.kuang</groupId> <artifactId>ssmbuild03</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <dependencies> <!--Junit--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <!--数据库驱动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 数据库连接池 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!--Servlet - JSP --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!--Mybatis--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.2</version> </dependency> <!--Spring--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.9.RELEASE</version> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> </resources> </build> </project>
src/mian/java
com.kuang.controller.BookController.java
package com.kuang.controller; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import com.kuang.pojo.Books; import com.kuang.service.BookService; @Controller @RequestMapping("/book") public class BookController { @Autowired @Qualifier("BookServiceImpl") private BookService bookService; @RequestMapping("/allBook") public String list(Model model) { List<Books> list = bookService.queryAllBook(); model.addAttribute("list", list); return "allbook"; } //跳转到增加书籍的页面 @RequestMapping("/toAddBook") public String toAddPaper() { return "addBook"; } //增加书籍的请求 @RequestMapping("/addBook") public String addPaper(Books books) { System.out.println("addBook=>"+books); bookService.addBook(books); return "redirect:/book/allBook";//重定向 } //跳转到修改页面 @RequestMapping("/toUpdate") //获得对象的id,方便修改页面显示出对象的值。并使用model携带 public String toUpdatePaper(int id,Model model) { Books books = bookService.queryBookById(id); model.addAttribute("QBook",books); return "updateBook"; } //修改书籍的请求 @RequestMapping("/updateBook") public String UpdateBook(Books books) { System.out.println("UpdateBook=>"+books); bookService.updateBook(books); return "redirect:/book/allBook";//重定向 } //删除书籍 //提交的id会转换为bookId,并且解析为int类型传到下面 @RequestMapping("/deleteBook/{bookId}") public String deleteBook(@PathVariable("bookId") int id) { bookService.deleteBookById(id); return "redirect:/book/allBook"; } }
com.kuang.dao.BookMapper.java
package com.kuang.dao; import java.util.List; import com.kuang.pojo.Books; public interface BookMapper { //增加一个Book int addBook(Books book); //根据id删除一个Book int deleteBookById(int id); //更新Book int updateBook(Books books); //根据id查询,返回一个Book Books queryBookById(int id); //查询全部Book,返回list集合 List<Books> queryAllBook(); }
com.kuang.dao.BookMapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.kuang.dao.BookMapper"> <!--增加一个Book--> <insert id="addBook" parameterType="Books"> insert into ssmbuild.books(bookName,bookCounts,detail) values (#{bookName}, #{bookCounts}, #{detail}) </insert> <!--根据id删除一个Book--> <delete id="deleteBookById" parameterType="int"> delete from ssmbuild.books where bookID=#{bookID} </delete> <!--更新Book--> <update id="updateBook" parameterType="Books"> update ssmbuild.books set bookName = #{bookName},bookCounts = #{bookCounts},detail = #{detail} where bookID = #{bookID} </update> <!--根据id查询,返回一个Book--> <select id="queryBookById" resultType="Books"> select * from ssmbuild.books where bookID = #{bookID} </select> <!--查询全部Book--> <select id="queryAllBook" resultType="Books"> SELECT * from ssmbuild.books </select> </mapper>
com.kuang.pojo.Books.java
package com.kuang.pojo; public class Books { private int bookID; private String bookName; private int bookCounts; private String detail; public Books() { super(); // TODO Auto-generated constructor stub } public Books(int bookID, String bookName, int bookCounts, String detail) { super(); this.bookID = bookID; this.bookName = bookName; this.bookCounts = bookCounts; this.detail = detail; } public int getBookID() { return bookID; } public void setBookID(int bookID) { this.bookID = bookID; } public String getBookName() { return bookName; } public void setBookName(String bookName) { this.bookName = bookName; } public int getBookCounts() { return bookCounts; } public void setBookCounts(int bookCounts) { this.bookCounts = bookCounts; } public String getDetail() { return detail; } public void setDetail(String detail) { this.detail = detail; } @Override public String toString() { return "Books [bookID=" + bookID + ", bookName=" + bookName + ", bookCounts=" + bookCounts + ", detail=" + detail + "]"; } }
com.kuang.service.BookService.java
package com.kuang.service; import java.util.List; import com.kuang.pojo.Books; public interface BookService { //增加一个Book int addBook(Books book); //根据id删除一个Book int deleteBookById(int id); //更新Book int updateBook(Books books); //根据id查询,返回一个Book Books queryBookById(int id); //查询全部Book,返回list集合 List<Books> queryAllBook(); }
com.kuang.service.BookServiceImpl.java
package com.kuang.service; import java.util.List; import com.kuang.dao.BookMapper; import com.kuang.pojo.Books; public class BookServiceImpl implements BookService { //调用dao层的操作,设置一个set接口,方便Spring管理 private BookMapper bookMapper; public void setBookMapper(BookMapper bookMapper) { this.bookMapper = bookMapper; } public int addBook(Books book) { return bookMapper.addBook(book); } public int deleteBookById(int id) { return bookMapper.deleteBookById(id); } public int updateBook(Books books) { return bookMapper.updateBook(books); } public Books queryBookById(int id) { return bookMapper.queryBookById(id); } public List<Books> queryAllBook() { return bookMapper.queryAllBook(); } }
src/mian/resources
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <import resource="spring-dao.xml"/> <import resource="spring-service.xml"/> <import resource="spring-mvc.xml"/> </beans>
database.properties
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8 jdbc.username=root jdbc.password=123456
mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!-- 添加日志 --> <settings> <setting name="logImpl" value="STDOUT_LOGGING"/> </settings> <typeAliases> <package name="com.kuang.pojo"/> </typeAliases> <mappers> <mapper resource="com/kuang/dao/BookMapper.xml"/> </mappers> </configuration>
spring-dao.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <!-- 配置整合mybatis --> <!-- 1.关联数据库文件 --> <context:property-placeholder location="classpath:database.properties"/> <!-- 2.数据库连接池 --> <!--数据库连接池 dbcp 半自动化操作 不能自动连接 c3p0 自动化操作(自动的加载配置文件 并且设置到对象里面) --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <!-- 配置连接池属性 --> <property name="driverClass" value="${jdbc.driver}"/> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <!-- c3p0连接池的私有属性 --> <property name="maxPoolSize" value="30"/> <property name="minPoolSize" value="10"/> <!-- 关闭连接后不自动commit --> <property name="autoCommitOnClose" value="false"/> <!-- 获取连接超时时间 --> <property name="checkoutTimeout" value="10000"/> <!-- 当获取连接失败重试次数 --> <property name="acquireRetryAttempts" value="2"/> </bean> <!-- 3.配置SqlSessionFactory对象 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 注入数据库连接池 --> <property name="dataSource" ref="dataSource"/> <!-- 配置MyBaties全局配置文件:mybatis-config.xml --> <property name="configLocation" value="classpath:mybatis-config.xml"/> </bean> <!-- 4.配置扫描Dao接口包,动态实现Dao接口注入到spring容器中 --> <!--解释 :https://www.cnblogs.com/jpfss/p/7799806.html--> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 注入sqlSessionFactory --> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> <!-- 给出需要扫描Dao接口包 --> <property name="basePackage" value="com.kuang.dao"/> </bean> </beans>
spring-mvc.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 配置SpringMVC --> <!-- 1.开启SpringMVC注解驱动 --> <mvc:annotation-driven /> <!-- 2.静态资源默认servlet配置--> <mvc:default-servlet-handler/> <!-- 3.配置jsp 显示ViewResolver视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> <!-- 4.扫描web相关的bean --> <context:component-scan base-package="com.kuang.controller" /> </beans>
spring-service.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- 扫描service相关的bean --> <context:component-scan base-package="com.kuang.service" /> <!--BookServiceImpl注入到IOC容器中--> <bean id="BookServiceImpl" class="com.kuang.service.BookServiceImpl"> <property name="bookMapper" ref="bookMapper"/> </bean> <!-- 配置事务管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <!-- 注入数据库连接池 --> <property name="dataSource" ref="dataSource" /> </bean> </beans>
前端
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://JAVA.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <!--DispatcherServlet--> <servlet> <servlet-name>DispatcherServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <!--一定要注意:我们这里加载的是总的配置文件,之前被这里坑了!--> <param-value>classpath:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>DispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--encodingFilter--> <filter> <filter-name>encodingFilter</filter-name> <filter-class> org.springframework.web.filter.CharacterEncodingFilter </filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!--Session过期时间--> <session-config> <session-timeout>15</session-timeout> </session-config> </web-app>
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <title>首页</title> <style type="text/css"> a { text-decoration: none; color: black; font-size: 18px; } h3 { width: 180px; height: 38px; margin: 100px auto; text-align: center; line-height: 38px; background: deepskyblue; border-radius: 4px; } </style> </head> <body> <h3> <a href="${pageContext.request.contextPath}/book/allBook">点击进入列表页</a> </h3> </body> </html>
addBook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>增加书籍</title> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container"> <div class="row clearfix"> <div class="col-md-12 column"> <div class="page-header"> <h1> <small>新增书籍</small> </h1> </div> </div> </div> <form action="${pageContext.request.contextPath}/book/addBook" method="post"> 书籍名称:<input type="text" name="bookName" required><br><br><br> 书籍数量:<input type="text" name="bookCounts" required><br><br><br> 书籍详情:<input type="text" name="detail" required><br><br><br> <input type="submit" value="添加"> </form> </div> </body> </html>
allbook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>书籍展示</title> <%-- BootStrap 美化界面 --%> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <%-- container一种格式边框 --%> <div class="container"> <%-- 清除浮动 --%> <div class="row clearfix"> <%-- 分割,将屏幕横向分成12份,md屏幕大小,12占满全部12份 --%> <div class="col-md-12 column"> <%-- 头部 --%> <div class="page-header"> <%-- small标签 --%> <h1> <small>书籍列表 ———— 显示所有书籍</small> </h1> </div> </div> </div> <div class="row clearfix"> <div class="col-md-4 column"> <%-- toAddBook --%> <a href="${pageContext.request.contextPath}/book/toAddBook">新增书籍</a> </div> </div> <div class="row clearfix"> <div class="col-md-12 column"> <table class="table table-hover table-striped"> <thead> <tr> <th>书籍编号</th> <th>书籍名称</th> <th>书籍数量</th> <th>书籍详情</th> <th>操作</th> </tr> </thead> <%-- 书籍从数据库中查询出来,从这个list中遍历出来:forEach(注意抬头引用) --%> <tbody> <%-- 获取数据 --%> <c:forEach var="book" items="${list}"> <tr> <td>${book.bookID}</td> <td>${book.bookName}</td> <td>${book.bookCounts}</td> <td>${book.detail}</td> <td> <%-- 发送修改消息,并且发现修改对象的id,让修改的时候可以看到对象值 --%> <a href="${pageContext.request.contextPath}/book/toUpdate?id=${book.bookID}">修改</a> | <a href="${pageContext.request.contextPath}/book/deleteBook/${book.bookID}">删除</a> </td> </tr> </c:forEach> </tbody> </table> </div> </div> </div> </body> </html>
updateBook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>修改书籍</title> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <div class="container"> <div class="row clearfix"> <div class="col-md-12 column"> <div class="page-header"> <h1> <small>修改书籍</small> </h1> </div> </div> </div> <%-- 原来在没有bookID时,运行出现问题:提交修改的SQL请求时出现问题,提交成功,但是内容没有修改 --%> <%-- 初次考虑是提交事务问题,配置完毕后发现依旧失败 --%> <%-- 看一下SQL语句,能否执行成功:SQL执行失败,修改未完成,发现会ID默认提交为0,和实际参数不符,数据库也没有这个参数 --%> <%-- 修改:增加bookID语句,可以使用前段传递隐藏域 --%> <%-- <input type="hidden" name="bookID" value="${QBook.bookID}"> --%> <%-- 我觉得显示ID更合理,readonly不可修改的内容,并染色 --%> <form action="${pageContext.request.contextPath}/book/updateBook" method="post"> ID:<input type="text" name="bookID" value="${QBook.bookID}" style="background:#FFFF00" readonly><br><br><br> 书籍名称:<input type="text" name="bookName" value="${QBook.bookName}" required><br><br><br> 书籍数量:<input type="text" name="bookCounts" value="${QBook.bookCounts}" required><br><br><br> 书籍详情:<input type="text" name="detail" value="${QBook.detail}" required><br><br><br> <input type="submit" value="修改"> </form> </div> </body> </html>
这个是同学们的第一个SSM整合案例,一定要烂熟于心!
SSM框架的重要程度是不言而喻的,学到这里,大家已经可以进行基本网站的单独开发。但是这只是增删改查的基本操作。可以说学到这里,大家才算是真正的步入了后台开发的门。也就是能找一个后台相关工作的底线。
或许很多人,工作就做这些事情,但是对于个人的提高来说,还远远不够!
我们后面还要学习一些 SpringMVC 的知识!
前路漫漫,认真坚持最重要
找不到project声明
Multiple annotations found at this line: schema_reference.4: Failed to read schema document 'https://maven.apache.org/xsd/maven-4.0.0.xsd', because could not find the document; the document could not be read; 3) the root element of the document is not <xsd:schema>. cvc-elt.1.a: Cannot find the declaration of element 'project'.
错误信息: 开发环境 eclipse ,maven项目,pom.xml第一行 <project …标签处一直报这个错误:cvc-elt.1: Cannot find the declaration of element ‘project’.
解决方法: 右键maven项目, maven——>update project ,记得勾选上 force update of snapshots/release
解决方法网址
发现eclipse的.properties文件中文出现乱码问题
第一步:windows–>properties–>General–>Content Types–>text(如下图)
解决方法网址
取消隐藏方法
解决方法网址
解决eclipse启动tomcat报错:Could not load the Tomcat server configuration at \Servers\Tomcat v6.0 Server at localhost-config. The Servers project is closed.
双击Servers即可
解决方法网址
在原代码上新增搜索功能
再原有的代码上进行补全:
dao层
/ssmbuild03/src/main/java/com/kuang/dao/BookMapper.java
//按名字搜索 Books queryBookName(@Param("bookName") String bookName);
/ssmbuild03/src/main/java/com/kuang/dao/BookMapper.xml
<!--按名字搜索--> <select id="queryBookName" resultType="Books"> select * from ssmbuild.books where bookName = #{bookName} </select>
service层
/ssmbuild03/src/main/java/com/kuang/service/BookService.java
//按名字搜索 Books queryBookName(String bookName);
/ssmbuild03/src/main/java/com/kuang/service/BookServiceImpl.java
@Override public Books queryBookName(String bookName) { return bookMapper.queryBookName(bookName); }
controller层
/ssmbuild03/src/main/java/com/kuang/controller/BookController.java
//查询书籍 @RequestMapping("/queryBook") public String queryBook(String queryBookName,Model model) { Books books = bookService.queryBookName(queryBookName); //由于allbook展示页面需要list类型存入 //所以将获得books存入list中,然后跳转展示页面 List<Books> list = new ArrayList<Books>(); list.add(books); //如果查询为空,就到显示页面 if (books==null) { list=bookService.queryAllBook(); model.addAttribute("error","未查到"); } model.addAttribute("list", list); return "allbook"; }
前端
allbook.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>书籍展示</title> <%-- BootStrap 美化界面 --%> <link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <%-- container一种格式边框 --%> <div class="container"> <%-- 清除浮动 --%> <div class="row clearfix"> <%-- 分割,将屏幕横向分成12份,md屏幕大小,12占满全部12份 --%> <div class="col-md-12 column"> <%-- 头部 --%> <div class="page-header"> <%-- small标签 --%> <h1> <small>书籍列表 ———— 显示所有书籍</small> </h1> </div> </div> </div> <div class="row clearfix"> <%-- 利用class="col-md-4 column",将内容分为三块。 class="btn btn-primary" 模型 style="float:right" 最右边 --%> <div class="col-md-4 column"> <%-- toAddBook --%> <a class="btn btn-primary" href="${pageContext.request.contextPath}/book/toAddBook">新增书籍</a> <a class="btn btn-primary" href="${pageContext.request.contextPath}/book/allBook">显示全部书籍</a> </div> <div class="col-md-4 column"></div> <div class="col-md-4 column"> <%-- 查询数据,需要使用form表单,a标签不能使用查询,form-inline变成一排的内联表单 --%> <form class="form-inline" action="${pageContext.request.contextPath}/book/queryBook" method="post" style="float:right"> <span style="color:red;">${error}</span> <input type="text" name="queryBookName" class="form-control" placeholder="请输入书籍名称"> <input type="submit" value="查询" class="btn btn-primary"> </form> </div> </div> <div class="row clearfix"> <div class="col-md-12 column"> <table class="table table-hover table-striped"> <thead> <tr> <th>书籍编号</th> <th>书籍名称</th> <th>书籍数量</th> <th>书籍详情</th> <th>操作</th> </tr> </thead> <%-- 书籍从数据库中查询出来,从这个list中遍历出来:forEach(注意抬头引用) --%> <tbody> <%-- 获取数据 --%> <c:forEach var="book" items="${list}"> <tr> <td>${book.bookID}</td> <td>${book.bookName}</td> <td>${book.bookCounts}</td> <td>${book.detail}</td> <td> <%-- 发送修改消息,并且发现修改对象的id,让修改的时候可以看到对象值 --%> <a href="${pageContext.request.contextPath}/book/toUpdate?id=${book.bookID}">修改</a> | <a href="${pageContext.request.contextPath}/book/deleteBook/${book.bookID}">删除</a> </td> </tr> </c:forEach> </tbody> </table> </div> </div> </div> </body> </html>
Bootstrap可视化布局https://www.bootcss.com/p/layoutit/
帮助前端设计,可以直接获得代码
AJAX = Asynchronous JavaScript and XML(异步的 JavaScript 和 XML)。
AJAX 是一种在无需重新加载整个网页的情况下,能够更新部分网页的技术。
Ajax 不是一种新的编程语言,而是一种用于创建更好更快以及交互性更强的Web应用程序的技术。
在 2005 年,Google 通过其 Google Suggest 使 AJAX 变得流行起来。Google Suggest能够自动帮你完成搜索单词。
Google Suggest 使用 AJAX 创造出动态性极强的 web 界面:当您在谷歌的搜索框输入关键字时,JavaScript 会把这些字符发送到服务器,然后服务器会返回一个搜索建议的列表。
就和国内百度的搜索框一样!
传统的网页(即不用ajax技术的网页),想要更新内容或者提交一个表单,都需要重新加载整个网页。
使用ajax技术的网页,通过在后台服务器进行少量的数据交换,就可以实现异步局部更新。
使用Ajax,用户可以创建接近本地桌面应用的直接、高可用、更丰富、更动态的Web用户界面。
我们可以使用前端的一个标签来伪造一个ajax的样子。iframe标签
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>iframe测试体验页面无刷新</title> <!-- 所有的值变量,提前获取 --> <script> function go(){ var url = document.getElementById("url").value; document.getElementById("iframe1").src=url; } </script> </head> <body> <div> <p>请输入地址:</p> <p> <input type="text" id="url" > <input type="button" value="提交" onclick="go()"> </p> </div> <div> <iframe id="iframe1" style="width:100%;height:500px"></iframe> </div> </body> </html>
<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title>kuangshen</title> </head> <body> <script type="text/javascript"> window.onload = function(){ var myDate = new Date(); document.getElementById('currentTime').innerText = myDate.getTime(); }; function LoadPage(){ var targetUrl = document.getElementById('url').value; console.log(targetUrl); document.getElementById("iframePosition").src = targetUrl; } </script> <div> <p>请输入要加载的地址:<span id="currentTime"></span></p> <p> <input id="url" type="text" value="https://www.baidu.com/"/> <input type="button" value="提交" onclick="LoadPage()"> </p> </div> <div> <h3>加载页面位置:</h3> <iframe id="iframePosition" style="width: 100%;height: 500px;"></iframe> </div> </body> </html>
利用AJAX可以做:
纯JS原生实现Ajax我们不去讲解这里,直接使用jquery提供的,方便学习和使用,避免重复造轮子,有兴趣的同学可以去了解下JS原生XMLHttpRequest !
Ajax的核心是XMLHttpRequest对象(XHR)。XHR为向服务器发送请求和解析服务器响应提供了接口。能够以异步方式从服务器获取新数据。
jQuery 提供多个与 AJAX 有关的方法。
通过 jQuery AJAX 方法,您能够使用 HTTP Get 和 HTTP Post 从远程服务器上请求文本、HTML、XML 或 JSON – 同时您能够把这些外部数据直接载入网页的被选元素中。
jQuery 不是生产者,而是大自然搬运工。
jQuery 是一个库;js 的大量函数(方法)
jQuery Ajax本质就是 XMLHttpRequest,对他进行了封装,方便调用!
jQuery.ajax(...) 部分参数: url:请求地址 type:请求方式,GET、POST(1.9.0之后用method) headers:请求头 data:要发送的数据 contentType:即将发送信息至服务器的内容编码类型(默认: "application/x-www-form-urlencoded; charset=UTF-8") async:是否异步 timeout:设置请求超时时间(毫秒) beforeSend:发送请求前执行的函数(全局) complete:完成之后执行的回调函数(全局) success:成功之后执行的回调函数(全局) error:失败之后执行的回调函数(全局) accepts:通过请求头发送给服务器,告诉服务器当前客户端可接受的数据类型 dataType:将服务器端返回的数据转换成指定类型 "xml": 将服务器端返回的内容转换成xml格式 "text": 将服务器端返回的内容转换成普通文本格式 "html": 将服务器端返回的内容转换成普通文本格式,在插入DOM中时,如果包含JavaScript标签,则会尝试去执行。 "script": 尝试将返回值当作JavaScript去执行,然后再将服务器端返回的内容转换成普通文本格式 "json": 将服务器端返回的内容转换成相应的JavaScript对象 "jsonp": JSONP 格式使用 JSONP 形式调用函数时,如 "myurl?callback=?" jQuery 将自动替换 ? 为正确的函数名,以执行回调函数
/springmvc-06/src/main/resources/applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 自动扫描指定的包,下面所有注解类交给IOC容器管理 --> <context:component-scan base-package="com.kuang.controller" /> <!-- 静态资源过滤js使用 --> <mvc:default-servlet-handler /> <mvc:annotation-driven/> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/jsp/" /> <!-- 后缀 --> <property name="suffix" value=".jsp" /> </bean> </beans>
/springmvc-06/src/main/java/com/kuang/controller/AjaxController.java
package com.kuang.controller; import java.io.IOException; import javax.servlet.http.HttpServletResponse; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class AjaxController { @RequestMapping("/t1") public String test() { return "hello"; } //测试环境是否成功 @RequestMapping("/a1") public void a1(String name,HttpServletResponse response) throws IOException { System.out.println("a1:param->"+name); if ("kuangshen".equals(name)) { response.getWriter().print("true"); }else { response.getWriter().print("false"); } } }
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> <script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script> <script> function a(){ <%-- url:获取请求地址a1 data:传递数据,$("#username").val()获取到输入值,存入a1.name success:回调函数function(data);error:function()失败 alert:是否异步 --%> $.post({ url:"${pageContext.request.contextPath}/a1", data:{"name":$("#username").val()}, success:function(data){ alert(data); } }) } </script> </head> <body> <%-- 失去焦点的时候,发起一个请求到后台,onblur失去焦点事件 --%> 用户名:<input type="text" id="username" οnblur="a()"> </body> </html>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.5" xmlns="http://JAVA.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <!--DispatcherServlet--> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <!--一定要注意:我们这里加载的是总的配置文件,之前被这里坑了!--> <param-value>classpath:applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--encodingFilter--> <filter> <filter-name>encoding</filter-name> <filter-class> org.springframework.web.filter.CharacterEncodingFilter </filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.kuang</groupId> <artifactId>springmvc-06</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <dependencies> <!--Junit --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <!--数据库驱动 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 数据库连接池 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!--Servlet - JSP --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.2</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!--Mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.2</version> </dependency> <!--Spring --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.9.RELEASE</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.4</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-war-plugin</artifactId> <version>3.3.1</version> </plugin> </plugins> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <filtering>false</filtering> </resource> </resources> </build> </project>
测试结果
程序运行步骤
前段知识最少得要求:HTML + css:略懂 + js (超级熟练)
js:
ES6:import require
状态status
success:function(data,status){ console.log("data="+data); console.log("status="+status); //200成功,300重定向或者转发,400客户端错误,500服务器端错误 }error(){ }
创建实体类
/springmvc-06/src/main/java/com/kuang/pojo/User.java
package com.kuang.pojo; public class User { private String name; private int age; private String sex; public User() { super(); // TODO Auto-generated constructor stub } public User(String name, int age, String sex) { super(); this.name = name; this.age = age; this.sex = sex; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } @Override public String toString() { return "User [name=" + name + ", age=" + age + ", sex=" + sex + "]"; } }
添加数据
/springmvc-06/src/main/java/com/kuang/controller/AjaxController.java
package com.kuang.controller; import java.io.IOException; import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpServletResponse; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.kuang.pojo.User; @RestController //RestController不会返回到视图解析器去 public class AjaxController { @RequestMapping("/t1") public String test() { return "hello"; } //测试环境是否成功 @RequestMapping("/a1") public void a1(String name,HttpServletResponse response) throws IOException { System.out.println("a1:param->"+name); if ("kuangshen".equals(name)) { response.getWriter().print("true"); }else { response.getWriter().print("false"); } } //将对象返回到前段 @RequestMapping("/a2") public List<User> a2(){ List<User> userList = new ArrayList<User>(); //添加数据 userList.add(new User("狂神说java", 1, "男")); userList.add(new User("狂神说前端", 2, "女")); userList.add(new User("狂神说运维", 3, "男")); return userList; } }
创建Ajax异步加载器
test2.jsp
<table>
,展示<tr>
,数据<tbody>
(但是数据在后台,所以需要利用ajax请求获取数据)<script>
去获取,click
点击事件<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> <script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script> <script> $(function(){ $("#btn").click(function(){ /* $.post(url,param(可以省略),success) */ $.post("${pageContext.request.contextPath}/a2",function(data) { //console.log(data); var html=""; //JavaScript6新特性,var外面也可以调用,let只能在for用使用 for(var i = 0; i < data.length;i++){ html += "<tr>" + "<td>" + data[i].name + "</td>"+ "<td>" + data[i].age + "</td>"+ "<td>" + data[i].sex + "</td>"+ "</tr>" } $("#content").html(html); }); }) }); </script> <body> <input type="button" value="加载数据" id="btn"> <table> <tr> <td>姓名</td> <td>年龄</td> <td>性别</td> </tr> <tbody id="content"> <%-- 数据:后台 --%> </tbody> </table> </body> </head>
动态请求响应,局部刷新
请求页面
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> <script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script> <script> function a1(){ $.post({ url:"${pageContext.request.contextPath}/a3", data:{"name":$("#name").val()}, <%-- success回调函数 --%> success:function(data){ if(data.toString()==='ok'){ $("#userInfo").css("color","green"); }else{ $("#userInfo").css("color","red"); } $("#userInfo").html(data); } }) } function a2(){ $.post({ url:"${pageContext.request.contextPath}/a3", data:{"pwd":$("#pwd").val()}, <%-- success回调函数 --%> success:function(data){ if(data.toString()==='ok'){ $("#pwdInfo").css("color","green"); }else{ $("#pwdInfo").css("color","red"); } $("#pwdInfo").html(data); } }) } </script> </head> <body> <p> 用户名:<input type="text" id="name" οnblur="a1()"/> <span id="userInfo"></span> </p> <p> 密码:<input type="text" id="pwd" οnblur="a2()"/> <span id="pwdInfo"></span> </p> </body> </html>
Controller.java
@RequestMapping("/a3") public String a3(String name,String pwd){ String msg =""; if(name!=null) { //admin应该为数据库信息 if ("admin".equals(name)) { msg="ok"; }else { msg="false"; } } if(pwd!=null) { if ("123456".equals(pwd)) { msg="ok"; }else { msg="false"; } } return msg; }
json乱码问题
<mvc:annotation-driven> <mvc:message-converters register-defaults="true"> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <constructor-arg value="UTF-8"/> </bean> <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> <property name="objectMapper"> <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"> <property name="failOnEmptyBeans" value="false"/> </bean> </property> </bean> </mvc:message-converters> </mvc:annotation-driven>
报错No converter found for return value of type: class java.util.ArrayList]
解决办法,pom增加jackson依赖
<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.4</version> </dependency>
https://www.cnblogs.com/zhoujian43/p/6640804.html
和Context.xml
<mvc:annotation-driven/>
想他们依赖多个jackson,可能会报下面的错误
<properties> <jackson.version>2.5.4</jackson.version> </properties> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>${jackson.version}</version> </dependency>
Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter': Instantiation of bean failed; nested exception is
网站
SpringMVC的处理器拦截器类似于Servlet开发中的过滤器Filter,用于对处理器进行预处理和后处理。开发者可以自己定义一些拦截器来实现特定的功能。
过滤器与拦截器的区别:拦截器是AOP思想的具体应用。
过滤器
拦截器
那如何实现拦截器呢?
想要自定义拦截器,必须实现 HandlerInterceptor 接口。
1、新建一个Moudule , springmvc-07-Interceptor , 添加web支持
2、配置web.xml 和 springmvc-servlet.xml 文件
/springmvc-07/src/main/java/com/kuang/controller/Textcontroller.java
package com.kuang.controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class Textcontroller { @GetMapping("/t1") public String test() { System.out.println("Textcontroller---test"); return "ok"; } }
applicationContext.xml
<!-- 拦截器配置 --> <mvc:interceptors> <mvc:interceptor> <!-- 包括这个请求下面的所有的请求 --> <mvc:mapping path="/**"/> <!-- 谁去拦截 --> <bean class="com.kuang.config.MyInterceptor"/> </mvc:interceptor> </mvc:interceptors>
3、编写一个拦截器
/springmvc-07/src/main/java/com/kuang/config/MyInterceptor.java
package com.kuang.config; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class MyInterceptor implements HandlerInterceptor{ //return ture ;执行下一个拦截器,方向 //return false;不执行下一个拦截器 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("--------------处理前-----------"); return true; } //主要用上面的,下面主要功能是拦截日志 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { System.out.println("--------------处理后-----------"); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { System.out.println("--------------清理中-----------"); } }
创建一个主页
有登录页面(按钮)和首页(按钮)
/springmvc-07/src/main/webapp/index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <h1><a href="${pageContext.request.contextPath}/goLogin">登录页面</a></h1> <h1><a href="${pageContext.request.contextPath}/main">首页</a></h1> </body> </html>
创建一个前端控制层
/springmvc-07/src/main/java/com/kuang/controller/LoginController.java
package com.kuang.controller; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller @RequestMapping("/user") public class LoginController { @RequestMapping("/main") public String main() { return "main"; } @RequestMapping("/goLogin") public String login() { return "login"; } @RequestMapping("/login") public String login(HttpSession session,String username,String password,Model model) { //把用户的信息存在session中,方便向下传递; //model 返回用户信息 session.setAttribute("userLoginInfo", username); model.addAttribute("username", username); return "main"; } }
创建一个登录页面
/springmvc-07/src/main/webapp/jsp/login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <!-- 在web-inf下的所有页面或者资源,只能通过controller,或者sevlet进行访问 --> <h1>登录页面</h1> <form action="${pageContext.request.contextPath}/user/login" method="post"> 用户名:<input type="text" name="username"/> 密码:<input type="text" name="password"/> <input type="submit" value="提交"/> </form> </body> </html>
首页
/springmvc-07/src/main/webapp/jsp/main.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <h1>首页</h1> <!-- 首页显示用户信息 --> <span>${username}</span> </body> </html>
编写一个新拦截器
拦截未登录的用户,不能查看首页
/springmvc-07/src/main/java/com/kuang/config/LoginInterceptor.java
public class LoginInterceptor implements HandlerInterceptor{ @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)throws Exception { //放行:判断什么情况下需要登录 HttpSession session = request.getSession(); //登录页面直接放行 if(request.getRequestURI().contains("goLogin")){ return true; } //说明我在提交登录 if(request.getRequestURI().contains("login")){ return true; } //用户session有值的时候 if(session.getAttribute("userLoginInfo")!=null){ return true; } //判断什么情况下没有登录 request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request,response); return false; } }
?疑问:Login放行?那即使账号不正确或者不输入会不会也能登陆?
applicationContext.xml配置拦截器
添加LoginInterceptor父类user, 只拦截父类user目录下的所有请求
<!-- 拦截器配置 --> <mvc:interceptors> <mvc:interceptor> <!-- 包括这个请求下面的所有的请求 --> <mvc:mapping path="/user/**"/> <!-- 谁去拦截 --> <bean class="com.kuang.config.LoginInterceptor"/> </mvc:interceptor> </mvc:interceptors>
增加注销功能
注销动作,同时在login中添加Model获取用户信息
/springmvc-07/src/main/java/com/kuang/controller/LoginController.java
@RequestMapping("/login") public String login(HttpSession session,String username,String password,Model model) { //把用户的信息存在session中,方便向下传递; session.setAttribute("userLoginInfo", username); model.addAttribute("username",username); return "main"; } @RequestMapping("/goOut") public String goOut(HttpSession session) { //删除指定attr对象 session.removeAttribute("userLoginInfo"); return "main"; }
首页
/springmvc-07/src/main/webapp/jsp/main.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <h1>首页</h1> <!-- 首页显示用户信息 --> 用户信息:<span>${username}</span> <p> <a href="${pageContext.request.contextPath}/user/goOut">注销</a> </p> </body> </html>
?疑问:首页显示用户信息后,再次刷新网页用户信息就为空了
文件上传是项目开发中最常见的功能之一 ,springMVC 可以很好的支持文件上传,但是SpringMVC上下文中默认没有装配MultipartResolver,因此默认情况下其不能处理文件上传工作。如果想使用Spring的文件上传功能,则需要在上下文中配置MultipartResolver。
前端表单要求:为了能上传文件,必须将表单的method设置为POST,并将enctype设置为multipart/form-data。只有在这样的情况下,浏览器才会把用户选择的文件以二进制数据发送给服务器;
对表单中的 enctype 属性做个详细的说明:
<form action="" enctype="multipart/form-data" method="post"> <input type="file" name="file"/> <input type="submit"> </form>
一旦设置了enctype为multipart/form-data,浏览器即会采用二进制流的方式来处理表单数据,而对于文件上传的处理则涉及在服务器端解析原始的HTTP响应。在2003年,Apache Software Foundation发布了开源的Commons FileUpload组件,其很快成为Servlet/JSP程序员上传文件的最佳选择。
1、导入文件上传的jar包,commons-fileupload , Maven会自动帮我们导入他的依赖包 commons-io包;
<!--文件上传--> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency> <!--servlet-api导入高版本的--> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>4.0.1</version> </dependency>
2、配置bean:multipartResolver
【注意!!!这个bena的id必须为:multipartResolver , 否则上传文件会报400的错误!在这里栽过坑,教训!】
<!--文件上传配置--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 请求的编码格式,必须和jSP的pageEncoding属性一致,以便正确读取表单的内容,默认为ISO-8859-1 --> <property name="defaultEncoding" value="utf-8"/> <!-- 上传文件大小上限,单位为字节(10485760=10M) --> <property name="maxUploadSize" value="10485760"/> <property name="maxInMemorySize" value="40960"/> </bean>
CommonsMultipartFile 的 常用方法:
String getOriginalFilename():获取上传文件的原名
InputStream getInputStream():获取文件流
void transferTo(File dest):将上传文件保存到一个目录文件中
我们去实际测试一下
3、编写前端页面
<form action="/upload" enctype="multipart/form-data" method="post"> <input type="file" name="file"/> <input type="submit" value="upload"> </form>
4、Controller
package com.kuang.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.multipart.commons.CommonsMultipartFile; import javax.servlet.http.HttpServletRequest; import java.io.*; @Controller public class FileController { //@RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象 //批量上传CommonsMultipartFile则为数组即可 @RequestMapping("/upload") public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException { //获取文件名 : file.getOriginalFilename(); String uploadFileName = file.getOriginalFilename(); //如果文件名为空,直接回到首页! if ("".equals(uploadFileName)){ return "redirect:/index.jsp"; } System.out.println("上传文件名 : "+uploadFileName); //上传路径保存设置 String path = request.getServletContext().getRealPath("/upload"); //如果路径不存在,创建一个 File realPath = new File(path); if (!realPath.exists()){ realPath.mkdir(); } System.out.println("上传文件保存地址:"+realPath); InputStream is = file.getInputStream(); //文件输入流 OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件输出流 //读取写出 int len=0; byte[] buffer = new byte[1024]; while ((len=is.read(buffer))!=-1){ os.write(buffer,0,len); os.flush(); } os.close(); is.close(); return "redirect:/index.jsp"; } }
5、测试上传文件,OK!
采用file.Transto 来保存上传的文件
1、编写Controller
/* * 采用file.Transto 来保存上传的文件 */ @RequestMapping("/upload2") public String fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException { //上传路径保存设置 String path = request.getServletContext().getRealPath("/upload"); File realPath = new File(path); if (!realPath.exists()){ realPath.mkdir(); } //上传文件地址 System.out.println("上传文件保存地址:"+realPath); //通过CommonsMultipartFile的方法直接写文件(注意这个时候) file.transferTo(new File(realPath +"/"+ file.getOriginalFilename())); return "redirect:/index.jsp"; }
2、前端表单提交地址修改
3、访问提交测试,OK!
1、设置 response 响应头
2、读取文件 – InputStream
3、写出文件 – OutputStream
4、执行操作
5、关闭流 (先开后关)
代码实现:
@RequestMapping(value="/download") public String downloads(HttpServletResponse response ,HttpServletRequest request) throws Exception{ //修改只需要改这个位置 //要下载的图片地址 String path = request.getServletContext().getRealPath("/upload"); String fileName = "基础语法.jpg"; //1、设置response 响应头 response.reset(); //设置页面不缓存,清空buffer response.setCharacterEncoding("UTF-8"); //字符编码 response.setContentType("multipart/form-data"); //二进制传输数据 //设置响应头 response.setHeader("Content-Disposition", "attachment;fileName="+URLEncoder.encode(fileName, "UTF-8")); File file = new File(path,fileName); //2、 读取文件--输入流 InputStream input=new FileInputStream(file); //3、 写出文件--输出流 OutputStream out = response.getOutputStream(); byte[] buff =new byte[1024]; int index=0; //4、执行 写出操作 while((index= input.read(buff))!= -1){ out.write(buff, 0, index); out.flush(); } out.close(); input.close(); return null; }
前端
<a href="/download">点击下载</a>
测试,文件下载OK,大家可以和我们之前学习的JavaWeb原生的方式对比一下,就可以知道这个便捷多了!
拦截器及文件操作在我们开发中十分重要,一定要学会使用!
更简单的方法
如果创建一个statics文件夹,存放1.png
<a href="${pageContext.request.contextPath}/statics/1.png">下载图片</a>
直接使用a标签获取这个文件,获取这个文件就会下载