mybatis学习之CLOB、BLOB处理及多参数方法映射

CLOB数据mysql对应数据类型为longtext、BLOB类型为longblob：

model实体：

...
private Integer id;
private String name;
private int age;

private byte[] pic; // 映射blob
private String remark; // 映射longtext
...

1、blob、clob数据插入：

<insert id="insertStudent" parameterType="Student">
    insert into t_student values(null,#{name},#{age},#{pic},#{remark})
</insert>

对应Dao接口：

/**
* 插入学生
* @param student
* @return
*/
public int insertStudent(Student student);

junit测试：

@Test
    public void testInsert() throws Exception {
        logger.info("新增学生");
        Student student = new Student();
        student.setAge(12);
        student.setName("晁州");
        student.setRemark("长文本");
        byte[] pic = null;
        try {
            File file = new File("c://test.png");
            InputStream is = new FileInputStream(file);
            pic = new byte[is.available()];
            is.read(pic);
            is.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        student.setPic(pic);
        studentDao.insertStudent(student);
        sqlSession.commit();
    }

2、blob、clob数据查询（blob数据查询出来对应java的byte[]）：

<select id="getStudentById" parameterType="Integer" resultType="Student">
    select * from t_student where id = #{id}
</select>

Dao接口部分：

@Test
    public void testGet() throws Exception {
        logger.info("查询学生");
        Student student = studentDao.getStudentById(34);
        System.out.println(student);
        byte[] pic = student.getPic();
        try {
            File file = new File("c://output.png");
            OutputStream os = new FileOutputStream(file);
            os.write(pic);
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

3、mybatis的多参数查询：

Dao接口部分：

/**
     * 根据姓名和年龄进行查询（mybatis多参数查询）
     * @param name
     * @param age
     * @return
     */
    public List<Student> getStudentsBy2Args(String name,Integer age);

对应mapper映射：

<select id="getStudentsBy2Args" resultMap="StudentResult">
    select * from t_student where name like #{param1} and age = #{param2}        <!-- 与方法的参数顺序一一对应 -->
</select>

junit测试：

@Test
    public void testGetStudentsBy2Args() throws Exception {
        List<Student> students = studentDao.getStudentsBy2Args("%晁%", 24);
        for (Student student : students) {
            System.out.println("####### "+student);
        }
    }