Spring4 MVC HelloWord实例

Spring4 MVC HelloWord实例

Spring4 MVC入门教程

本教程是基于以下工具写的:
  • MyEclipse 10
  • Spring 4.0.3.RELEASE

2- 预览应用程序执行流程

Spring MVC DispatcherServlet 读取 xml 配置文件的原则:
  • {servlet-name} ==> /WEB-INF/{servlet-name}-servlet.xml

如果你不想用 SpringMVC 使用原则,可以重新配置 SpringMVC  DispatcherServlet 在 web.xml 文件中:
<servlet>
   <servlet-name>my-dispatcher-name</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <init-param>
       <!-- override default name {servlet-name}-servlet.xml -->
       <param-name>contextConfigLocation</param-name>
       <param-value>/WEB-INF/springmvc-myconfig.xml</param-value>
   </init-param>
   <load-on-startup>1</load-on-startup>
</servlet>
应用程序的流程:

3 - 创建Maven工程

创建Maven项目类型。 Maven是帮助我们管理库的最好方式。
在 Eclipse, 选择 "File/New/Other..."


选择 archetype "maven-archetype-webapp"。

输入:
  • Group Id: com.zyiz
  • Artifact Id: HelloSpringMVC
  • Package: com.zyiz.springmvc

这样将创建项目,结构如下图所示:

不要担心项目在创建的时候出现错误信息。原因是,现在我们还没有声明 Servlet 库。
在 Eclipse 中创建 Maven 项目结构可能是错误的。需要我们去检查出来并完善。

4- 配置Spring

这是项目建成后的文件结构图:

配置 Maven 使用 Spring 库.
  • pom.xml
<projectxmlns="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
     http://maven.apache.org/maven-v4_0_0.xsd">
 
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.zyiz</groupId>
    <artifactId>HelloSpringMVC</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>HelloSpringMVC Maven Webapp</name>
    <url>http://maven.apache.org</url>
 
 
    <dependencies>
 
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
 
        <!-- Servlet Library -->
        <!-- http://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
 
        <!-- Spring dependencies -->
        <!-- http://mvnrepository.com/artifact/org.springframework/spring-core -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.1.4.RELEASE</version>
        </dependency>
 
        <!-- http://mvnrepository.com/artifact/org.springframework/spring-web -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>4.1.4.RELEASE</version>
        </dependency>
 
        <!-- http://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.4.RELEASE</version>
        </dependency>
 
    </dependencies>
     
    <build>
        <finalName>HelloSpringMVC</finalName>
        <plugins>
         
            <!-- Config: Maven Tomcat Plugin -->
            <!-- http://mvnrepository.com/artifact/org.apache.tomcat.maven/tomcat7-maven-plugin -->
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <!-- Config: contextPath and Port (Default - /HelloSpringMVC : 8080) -->
                <!--
                <configuration>
                    <path>/</path>
                    <port>8899</port>
                </configuration>
                -->   
            </plugin>
        </plugins>
    </build>   
     
</project>
配置 web.xml:
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
   id="WebApp_ID" version="3.0">
    
   <display-name>HelloWorldSpring</display-name>
    
   <servlet>
       <servlet-name>spring-mvc</servlet-name>
       <servlet-class>
           org.springframework.web.servlet.DispatcherServlet
       </servlet-class>
       <load-on-startup>1</load-on-startup>
   </servlet>   
    
   <servlet-mapping>
       <servlet-name>spring-mvc</servlet-name>
       <url-pattern>/</url-pattern>
   </servlet-mapping>
 
    <!-- Other XML Configuration -->
   <!-- Load by Spring ContextLoaderListener -->
   <context-param>
       <param-name>contextConfigLocation</param-name>
       <param-value>/WEB-INF/root-context.xml</param-value>
   </context-param>
 
    
    <!-- Spring ContextLoaderListener -->
   <listener>
       <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>
    
</web-app>
Spring MVC 的 DispatcherServlet将根据原则读取XML配置文件:
  • {servlet-name} ==> /WEB-INF/{servlet-name}-servlet.xml

  • spring-mvc-servlet.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:p="http://www.springframework.org/schema/p"
    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-4.1.xsd 
      http://www.springframework.org/schema/context
      http://www.springframework.org/schema/context/spring-context-4.1.xsd 
      http://www.springframework.org/schema/mvc
      http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
 
   <context:component-scan base-package="com.zyiz.tutorial.springmvc"/>
    
   <context:annotation-config/>
    
   <bean
       class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        
       <property name="prefix">
           <value>/WEB-INF/pages/</value>
       </property>
        
       <property name="suffix">
           <value>.jsp</value>
       </property>       
        
   </bean>
    
</beans>
:
在Spring应用程序 ContextLoaderListener 将读取其他 XML 配置文件(如下的 abc.xml 和 root-context.xml 两个文件)。 可能不需要配置 ContextLoaderListener,如果你的应用程序并不需要读取其他XML配置文件。
<!-- web.xml -->
<!-- Spring ContextLoaderListener -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
 
<!-- Load by Spring ContextLoaderListener -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
       /WEB-INF/root-context.xml,
       /WEB-INF/abc.xml
 </param-value>
</context-param>
  • /WEB-INF/root-context.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">
 
  <!-- Empty -->
 
</beans>
  • HelloWorldController.java
package com.zyiz.springmvc;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
 
@Controller
public class HelloWorldController {
 
    @RequestMapping("/hello")
    public String hello(Model model) {
         
        model.addAttribute("greeting", "Hello Spring MVC");
         
        return"helloworld";
         
    }
 
}

  • helloworld.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Spring4 MVC -HelloWorld</title>
</head>
<body>
    <h1>${greeting}</h1>
</body>
</html>

5- 运行Spring应用程序

首先,运行应用程序之前,需要构建整个项目。
右键单击该项目并选择:
  • Run As/Maven install



运行配置:



输入:
  • Name: Run HelloSpringMVC
  • Base directory: ${workspace_loc:/HelloSpringMVC} =>${workspace_loc:/HelloSpringMVC Maven Webapp}
  • Goals: tomcat7:run

点击Run:

第一次运行该程序将需要几分钟(看你的网速),它需要下载 Tomcat 插件库才能运行。
一切准备就绪:

运行URL,如下图:

6 - 应用程序的流程

完成您的项目后,并成功地在上一步中运行。现在,我们来看一看程序的运行方式。

7- 控制器和方法

7.1- HttpServletRequest & HttpServletResponse

可以使用 HttpServletRequest, HttpServletResponse 在控制器的方法中。
  • OtherExampleController.java
package com.zyiz.springmvc;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
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 org.springframework.web.bind.annotation.RequestParam;
 
@Controller
public class OtherExampleController {
 
   ......
 
   @RequestMapping("/somePath")
   public String requestResponseExample(HttpServletRequest request,
           HttpServletResponse reponses, Model model) {
 
       // Todo something here
 
       return "someView";
   }
 
   ......
}

7.2- 控制器中的重定向

使用前缀 "redirect:" ,该方法返回字符串,可以重定向到另一页面。参见图:
  • RedirectExampleController.java
package com.zyiz.springmvc;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
 
@Controller
public class RedirectExampleController {
 
    @RequestMapping(value = "/redirect", method = RequestMethod.GET)
    public String authorInfo(Model model) {
 
       // Do somethong here
 
        return "redirect:/hello";
    }
}
运行URL:

7.3- @RequestParam示例

使用@RequestParam 注解将请求参数绑定到你的控制器方法参数。
下面的代码片段显示了这个用法:
  • RequestParamExampleController.java
package com.zyiz.springmvc;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
 
@Controller
public class RequestParamExampleController {
     
    @RequestMapping("/user")
    public String userInfo(Model model,
            @RequestParam(value = "name", defaultValue = "Guest") String name) {
 
        model.addAttribute("name", name);
 
        if("admin".equals(name)) {
            model.addAttribute("email", "admin@zyiz.net");
        } else{
            model.addAttribute("email", "Not set");
        }
        return "userInfo";
    }
  
}
  • /WEB-INF/pages/userInfo.jsp
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>User Info</title>
</head>
<body>
 
   <h2>${name}</h2>
 
   Email: ${email}
   <br>
</body>
</html>
运行 URL:

7.4- @PathVariable示例

在Spring MVC中,可以使用@PathVariable注释将一个方法参数绑定到一个URI模板变量的值:
例如,这是一个模板的URI:
  • /web/fe/{sitePrefix}/{language}/document/{id}/{naturalText}
而下面的 URI 模板匹配上面:
  1. /web/fe/default/en/document/8108/spring-mvc-for-beginners
  2. /web/fe/default/vi/document/8108/spring-mvc-cho-nguoi-moi-bat-dau
  3. .....

下面的代码片段显示了用法:
  • PathVariableExampleController.java
package com.zyiz.springmvc;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
 
@Controller
public class PathVariableExampleController {
  
 
    /**
     * @PathVariable Example:
     *
     */
    @RequestMapping("/web/fe/{sitePrefix}/{language}/document/{id}/{naturalText}")
    public String documentView(Model model,
            @PathVariable(value = "sitePrefix") String sitePrefix,
            @PathVariable(value = "language") String language,
            @PathVariable(value = "id") Long id,
            @PathVariable(value = "naturalText") String naturalText) {
 
        model.addAttribute("sitePrefix", sitePrefix);
        model.addAttribute("language", language);
        model.addAttribute("id", id);
        model.addAttribute("naturalText", naturalText);
 
        String documentName = "Java tutorial for Beginners";
        if(id == 8108) {
            documentName = "Spring MVC for Beginners";
        }
 
        model.addAttribute("documentName", documentName);
 
        return "documentView";
    }
}
  • /WEB-INF/pages/documentView.jsp
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>${documentName}</title>
</head>
<body>
 
    <h3>${documentName}</h3>
 
    Site Prefix: ${sitePrefix}
    <br> Language: ${language}
    <br> ID: ${id}
    <br> Natural Text: ${naturalText}
    <br>
 
</body>
</html>
运行 URL:

7.5- @ResponseBody示例

如果您使用 @ResponseBody 注释到方法, spring 将尝试转换它的返回值,并自动写入到HTTP响应。在这种情况下,并不需要一个特定的视图。
注:方法不一定需要返回字符串类型。


使用@ResponseBody和方法返回字符串的简单例子。

  • ResponseBodyExample1Controller.java
package com.zyiz.springmvc;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
@Controller
public class ResponseBodyExample1Controller {
 
    // Simple example, method returns String.
    @RequestMapping(value = "/saveResult")
    @ResponseBody
    publicString authorInfo(Model model) {
        return "saved";
    }
 
     
}
运行示例的结果:
使用@ResponseBody 的一个例子,方法返回一个对象。
代码下载:http://pan.baidu.com/s/1mgYKoA0
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