DBUtils提供的jar包实现CRUD操作

导入jar包：

commons-dbutils-1.3.jar

使用现成的jar中的QueryRunner测试增、删、改的操作:

//测试插入

@Test
public void testInsert(){
    Connection connection = null;
    try {
        QueryRunner runner = new QueryRunner();
        connection = JDBCUtils.getConnection();
        String sql = "insert into customers(name,email,birth)values(?,?,?)";
        int insertCount = runner.update(connection, sql, "张三", "zhangsan@126.com", "2000-09-08");
        System.out.println("添加了"+ insertCount + "条记录");
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        JDBCUtils.closeResource(connection,null);
    }
}

使用现成的jar中的QueryRunner测试查询的操作:

/**
 * 测试查询
 * BeanHandler:是ResultHandler接口的实现类，用于封装表中的一条记录
 */
@Test
public void testQuery1(){
    Connection connection = null;
    try {
        QueryRunner runner = new QueryRunner();
        connection = JDBCUtils.getConnection();
        String sql = "select id,name ,email,birth from customers where id = ?";
        BeanHandler<Customer> beanHandler = new BeanHandler<>(Customer.class);
        Customer customer = runner.query(connection, sql, beanHandler, 22);
        System.out.println("customer = " + customer);
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        JDBCUtils.closeResource(connection,null);
    }
}
/**
* BeanListHandler:是ResultHandler接口的实现类，用于封装表中的多条记录构成的集合
 */
@Test
public void testQuery2(){
    Connection connection = null;
    try {
        QueryRunner runner = new QueryRunner();
        connection = JDBCUtils.getConnection();
        String sql = "select id,name ,email,birth from customers where id < ?";
        BeanListHandler<Customer> handler = new BeanListHandler<>(Customer.class);
        List<Customer> customers = runner.query(connection, sql, handler, 22);
        customers.forEach(System.out::println);
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        JDBCUtils.closeResource(connection,null);
    }
}

使用dbutils.jar包中的DbUtils工具类实现连接等资源的关闭：

public static void closeResource1(Connection conn,Statement ps,ResultSet rs){
		DbUtils.closeQuietly(conn);
		DbUtils.closeQuietly(ps);
		DbUtils.closeQuietly(rs);
}