mybatis入门（五）

根据用户名称模糊查询用户信息

@Test
    public void findUserByNameTest() throws IOException {
        // 通过工厂得到SqlSession
        SqlSession sqlSession = null;
        try {
            // mybatis配置文件
            String resource = "SqlMapConfig.xml";
            // 得到配置文件流
            InputStream inputStream = Resources.getResourceAsStream(resource);
            // 创建会话工厂，传入mybatis的配置文件信息
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
                    .build(inputStream);
            sqlSession = sqlSessionFactory.openSession();
            // 通过SqlSession操作数据库
            // 第一个参数：映射文件中statement的id，等于=namespace+"."+statement的id
            // 第二个参数：指定和映射文件中所匹配的parameterType类型的参数
            // sqlSession.selectOne结果 是与映射文件中所匹配的resultType类型的对象
            List<User> list = sqlSession
                    .selectList("test.findUserByName", "小明");
            System.out.println(list);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (sqlSession != null) {
                // 释放资源
                sqlSession.close();
            }

        }
    }

User.xml

<!-- 根据用户名称模糊查询用户信息，可能返回多条
    resultType：指定就是单条记录所映射的java对象 类型
    ${}:表示拼接sql串，将接收到参数的内容不加任何修饰拼接在sql中。
    使用${}拼接sql，引起 sql注入
    ${value}：接收输入 参数的内容，如果传入类型是简单类型，${}中只能使用value
     -->
    <select id="findUserByName" parameterType="String" resultType="ql.mybatis.pojo.User">
        SELECT * FROM USER WHERE username LIKE '%${value}%'
    </select>

结果：

DEBUG [main] - Logging initialized using 'class org.apache.ibatis.logging.slf4j.Slf4jImpl' adapter.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - PooledDataSource forcefully closed/removed all connections.
DEBUG [main] - Opening JDBC Connection
DEBUG [main] - Created connection 1426420214.
DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@550571f6]
DEBUG [main] - ==>  Preparing: SELECT * FROM USER WHERE username LIKE '%小明%'
DEBUG [main] - ==> Parameters:
DEBUG [main] - <==      Total: 3
[User [id=16, username=张小明, sex=1, birthday=null, address=河南郑州], User [id=22, username=陈小明, sex=1, birthday=null, address=河南郑州], User [id=25, username=陈小明, sex=1, birthday=null, address=河南郑州]]
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@550571f6]
DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@550571f6]
DEBUG [main] - Returned connection 1426420214 to pool.

注意：输出的日志的sql语句不是用？占位符的，所以会引起sql注入