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使用Jdbc Template的基本操作步骤

时间:2021-07-01 10:21:17 帮助过:2人阅读

="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//
     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//
     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//
     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());
     }
     
     
 
 }

 

使用Jdbc Template的基本操作步骤

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