Spring JDBC PreparedStatementSetter接口示例
Spring JDBC PreparedStatementSetter接口示例
org.springframework.jdbc.core.PreparedStatementSetter接口充当JdbcTemplate类使用的一般回调接口。该接口在JdbcTemplate类提供的PreparedStatement上设置了使用相同SQL的批处理中的每个更新的值。实现负责设置必要的参数。已经提供带有占位符的SQL，使用此接口比PreparedStatementCreator更容易：JdbcTemplate将创建PreparedStatement，回调仅负责设置参数值。
接口的声明
以下是org.springframework.jdbc.core.PreparedStatementSetter接口的声明 -
public interface PreparedStatementSetter
用法
步骤1 - 使用配置的数据源创建一个JdbcTemplate对象。
步骤2 - 使用JdbcTemplate对象方法进行数据库操作，同时传递PreparedStatementSetter对象来替换查询中的占位符。
实例
以下示例将演示如何使用JdbcTemplate类和PreparedStatementSetter接口进行读取查询。这里我们将从student表中读取记录。
语法
final String SQL = "select * from Student where id = ? ";
List <Student> students = jdbcTemplateObject.query(SQL, new PreparedStatementSetter() {
public void setValues(PreparedStatement preparedStatement) throws SQLException {
preparedStatement.setInt(1, id);
}
},
new StudentMapper());
在上面示例(语法)代码中 -
- SQL - 选择查询语句来来读取学生记录信息。
- jdbcTemplateObject -
StudentJDBCTemplate对象从数据库中读取Student对象。 - PreparedStatementSetter -
PreparedStatementSetter对象在查询中设置参数。 - StudentMapper -
StudentMapper是一个RowMapper对象，用于将每个获取的记录映射到学生对象。
实例项目
要了解上述与Spring JDBC相关的概念，下面我们编写一个select查询语句的示例。打开Eclipse IDE，并按照以下步骤创建一个Spring应用程序，这里创建一个名称为：PreparedStatementSetter 的项目。
步骤说明
- 参考第一个Spring JDBC项目来创建一个Maven项目 - http://www.zyiz.net/springjdbc/first_application.html
- 更新bean配置并运行应用程序。
完整的项目结构如下所示 -
以下是Maven配置文件：pom.xml的代码内容：
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.zyiz</groupId>
<artifactId>PreparedStatementSetter</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>PreparedStatementSetter</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.40</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.1.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.1.4.RELEASE</version>
</dependency>
</dependencies>
</project>
以下是数据访问对象接口文件：StudentDAO.java的内容：
package com.zyiz;
import java.util.List;
import javax.sql.DataSource;
public interface StudentDAO {
/**
* This is the method to be used to initialize database resources ie.
* connection.
*/
public void setDataSource(DataSource ds);
/**
* This is the method to be used to list down all the records from the
* Student table.
*/
public List<Student> listStudents();
public Student getStudent(Integer id);
public void create(String name, Integer age);
}
以下是文件：Student.java的代码内容：
package com.zyiz;
public class Student {
private Integer age;
private String name;
private Integer id;
public void setAge(Integer age) {
this.age = age;
}
public Integer getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getId() {
return id;
}
}
以下是文件：StudentMapper.java的代码内容：
package com.zyiz;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
public class StudentMapper implements RowMapper<Student> {
public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
Student student = new Student();
student.setId(rs.getInt("id"));
student.setName(rs.getString("name"));
student.setAge(rs.getInt("age"));
return student;
}
}
实现类StudentJDBCTemplate.java实现了定义的DAO接口 - StudentDAO.java，以下是文件：StudentJDBCTemplate.java的代码内容：
package com.zyiz;
import java.sql.PreparedStatement;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ParameterizedPreparedStatementSetter;
import org.springframework.jdbc.core.PreparedStatementSetter;
import java.sql.SQLException;
public class StudentJDBCTemplate implements StudentDAO {
private DataSource dataSource;
private JdbcTemplate jdbcTemplateObject;
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
this.jdbcTemplateObject = new JdbcTemplate(dataSource);
}
public List<Student> listStudents() {
String SQL = "select * from Student";
List<Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
return students;
}
public void create(String name, Integer age) {
// TODO Auto-generated method stub
String insertQuery = "insert into student (name, age) values (?, ?)";
jdbcTemplateObject.update(insertQuery, name, age);
System.out.println("Created Record Name = " + name + " Age = " + age);
return;
}
public Student getStudent(final Integer id) {
final String SQL = "select * from Student where id = ? ";
List<Student> students = jdbcTemplateObject.query(SQL, new PreparedStatementSetter() {
public void setValues(PreparedStatement preparedStatement) throws SQLException {
preparedStatement.setInt(1, id);
}
}, new StudentMapper());
return students.get(0);
}
}
以下是文件：MainApp.java的代码内容：
package com.zyiz;
import java.util.ArrayList;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.zyiz.StudentJDBCTemplate;
public class MainApp {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("application-beans.xml");
StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate) context.getBean("studentJDBCTemplate");
System.out.println("------Records Creation--------");
studentJDBCTemplate.create("Maxsu", 21);
studentJDBCTemplate.create("Curry", 22);
studentJDBCTemplate.create("Suzend", 23);
System.out.println("------Get Student Info by ID=1 --------");
Student student = studentJDBCTemplate.getStudent(1);
System.out.print("ID : " + student.getId());
System.out.println(", Age : " + student.getAge());
System.out.println("------Listing Multiple Records--------");
List<Student> students = studentJDBCTemplate.listStudents();
for (Student record : students) {
System.out.print("ID : " + record.getId());
System.out.print(", Name : " + record.getName());
System.out.println(", Age : " + record.getAge());
}
}
}
以下是文件：application-beans.xml的代码内容：
<?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-3.0.xsd ">
<!-- Initialization for data source -->
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=true" />
<property name="username" value="root" />
<property name="password" value="123456" />
</bean>
<!-- Definition for studentJDBCTemplate bean -->
<bean id="studentJDBCTemplate" class="com.zyiz.StudentJDBCTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
</beans>
注意： application-beans.xml 文件的位置是：{workspace}/fistapp/src/main/java 目录，如果放置错了，程序可能会因为找不到此配置文件而出错。
完成创建源代码和bean和数据库连接信息的文件配置后，运行应用程序。这里先简单说明一下运行的步骤，在项目名称(PreparedStatementSetter)上点击右键，在弹出的菜单中选择：【Run As】-> 【Maven test】
在运行测试成功后，应该会输出类似以下内容(含有 BUILD SUCCESS 的信息) 。
接下来，点击类文件：MainApp.java 选择【Run As】->【Java Application】，如果应用程序一切正常，这将打印以下结果：
------Records Creation-------- Created Record Name = Maxsu Age = 21 Created Record Name = Curry Age = 22 Created Record Name = Suzend Age = 23 ------Get Student Info by ID=1 -------- ID : 1, Age : 21 ------Listing Multiple Records-------- ID : 1, Name : Maxsu, Age : 21 ID : 2, Name : Curry, Age : 22 ID : 3, Name : Suzend, Age : 23
目录
Spring JDBC批处理示例
Spring JDBC对象
