使用Jdbc Template的基本操作步骤

　1.appliactionContext.xml配置

<?xml version="1.0" encoding="UTF-8"?>
  <beans xmlns="http://www.springframework.org/schema/beans"
         xmlns:p="http://www.springframework.org/schema/p"
         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">
      
      <!--数据源的配置 -->
      <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
         <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
         <property name="url" value="jdbc:mysql:///spring"></property>
         <property name="username" value="root"></property>
         <property name="password" value=""></property>
     </bean>
     
     
 　　
     <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
         <property name="dataSource" ref="dataSource"></property>
     </bean>
     
     
     <bean id="userDao" class="cn.happy.impl.UserDAOImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
     </bean>
 
 </beans>

　　2.接口：IUserDAO.java

 public interface IUserDAO {
  
      public void addUser(User user);
 
     public void deleteUser(int id);
 
     public void updateUser(User user);
 
     public String searchUserName(int id);
     
     public User searchUser(int id);
     
     public List<User> findAll();
 
 }

3.接口实现类：UserDAOImpl.java

Spring提供了JdbcDaoSupport支持类，所有DAO继承这个类，就会自动获得JdbcTemplate（前提是注入DataSource）。

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
         <property name="dataSource" ref="dataSource"></property>
     </bean>
     
     
     <bean id="userDao" class="cn.happy.impl.UserDAOImpl">
         <property name="jdbcTemplate" ref="jdbcTemplate"></property>
     </bean>

JdbcTemplate主要提供下列方法：

　　1、execute方法：可以用于执行任何SQL语句，一般用于执行DDL语句；

　　2、update方法及batchUpdate方法：update方法用于执行新增、修改、删除等语句；batchUpdate方法用于执行批处理相关语句；

　　3、query方法及queryForXXX方法：用于执行查询相关语句；

　　4、call方法：用于执行存储过程、函数相关语句。

public class UserDAOImpl extends JdbcDaoSupport implements IUserDAO {
 
     public void addUser(User user) {
         String sql = "insert into user values(?,?,?)";
         this.getJdbcTemplate().update(sql, user.getId(), user.getUsername(),
                 user.getPassword());
     }
 
     public void deleteUser(int id) {
         String sql = "delete from user where id=?";
         this.getJdbcTemplate().update(sql, id);
 
     }
 
     public void updateUser(User user) {
         String sql = "update user set username=?,password=? where id=?";
         this.getJdbcTemplate().update(sql, user.getUsername(),
                 user.getPassword(), user.getId());
     }
 
     public String searchUserName(int id) {// 简单查询，按照ID查询，返回字符串
         String sql = "select username from user where id=?";
         // 返回类型为String(String.class)
         return this.getJdbcTemplate().queryForObject(sql, String.class, id);
 
     }
 
     public List<User> findAll() {// 复杂查询返回List集合
         String sql = "select * from user";
         return this.getJdbcTemplate().query(sql, new UserRowMapper());
 
     }
 
     public User searchUser(int id) {
         String sql="select * from user where id=?";
         return this.getJdbcTemplate().queryForObject(sql, new UserRowMapper(), id);
     }
 
     class UserRowMapper implements RowMapper<User> {
 　　　　　//rs为返回结果集，以每行为单位封装着
         public User mapRow(ResultSet rs, int rowNum) throws SQLException {
     
             User user = new User();
             user.setId(rs.getInt("id"));
             user.setUsername(rs.getString("username"));
             user.setPassword(rs.getString("password"));
             return user;
         }
 
    }
 
 }

4.测试类：UserTest.java

public class UserTest {
     
     @Test//增
     public void demo1(){
         User user=new User();
         user.setId(3);
         user.setUsername("admin");
         user.setPassword("123456");
         
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         dao.addUser(user);
         
     }
     
     @Test//改
     public void demo2(){
         User user=new User();
         user.setId(1);
         user.setUsername("admin");
        user.setPassword("admin");
         
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         dao.updateUser(user);
     }
     
     @Test//删
     public void demo3(){
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         dao.deleteUser(3);
     }
     
     @Test//查（简单查询，返回字符串）
     public void demo4(){
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         String name=dao.searchUserName(1);
         System.out.println(name);
     }
     
     @Test//查（简单查询，返回对象）
     public void demo5(){
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         User user=dao.searchUser(1);
         System.out.println(user.getUsername());
     }
     
     @Test//查（复杂查询，返回对象集合）
     public void demo6(){
         ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
         IUserDAO dao=(IUserDAO) applicationContext.getBean("userDao");
         List<User> users=dao.findAll();
         System.out.println(users.size());
     }
     
     
 
 }