J2EE进阶学习——Spring框架（六）——JdbcTempl

先导包

spring-jdbc、spring-tx、mysql驱动包，具体的自己去下载或者搜索

增加

• 创建对象，设置数据库

DriverManagerDataSource datasource = new DriverManagerDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUrl("jdbc:mysql:///user");
dataSource.setUsername("xxxx");
dataSource.setPassword("xxxxxx");

• 创建jdbcTemplate对象，设置数据源

JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
String sql = "insert into t_user values(?,?);

• 调用jdbcTemplate对象里面的方法实现操作

//更新的行数
int row = jdbcTemplate.update(sql,"xxx","xxx");
System.out.println(row);

修改

    @Test
    public void update(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql:///user");
        dataSource.setUsername("xxxx");
        dataSource.setPassword("xxxxxx");

        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        String sql = "update t_user set password=? where username=?";
        int row = jdbcTemplate.update(sql,"456789","TiHom");
        System.out.println(row);
    }

删除

@Test
    public void delete(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql:///user");
        dataSource.setUsername("xxxx");
        dataSource.setPassword("xxxxxx");

        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        String sql = "delete from t_user where username=?";
        int row = jdbcTemplate.update(sql,"TiHom");
        System.out.println(row);
    }

查询

• 查询返回对象

@Test
    public void search(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql:///user");
        dataSource.setUsername("xxxx");
        dataSource.setPassword("xxxxxx");

        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        String sql = "select * from t_user where username=?";
        //第二个参数需要自己实现接口实现类，自己做数据封装
        User user = jdbcTemplate.queryForObject(sql,new MyRowMapper(),"TiHom");
        
        System.out.println(user);
    }

MyRowMapper实现类

class MyRowMapper implements RowMapper<User>{
    @Override
    public User mapRow(ResultSet resultSet, int i) throws SQLException {
        //从结果集中获取数据
        String username = resultSet.getString("username");
        String password = resultSet.getString("password");
        User user = new User();
        //将数据封装到对象里面
        user.setUsername(username);
        user.setPassword(password);
        return user;
    }
}

• 查询返回list集合
  只需改动一处
  String sql = "select * from t_user";
  List<User> list = jdbcTemplate.query(sql,new MyRowMapper());