今天完成的事情：用Mybatis编写了DAO层 ，并且用JUnit进行测试

明天计划的事情：学习Spring

遇到的问题：log4j不能用：是不是log4j.properties路径不正确？还是配置有问题？还是其他原因？

首先在这个目录下建立了log4j.properties

（试过把放在src/ 或 src/ main/ 或 src/ main/java/ 或 src/ main/java/mapperDao/ 下，都不行）

加载jar包

配置log4j.properties

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

（从网上copy了很多种配制方法都不能用）

最后提示

收获：

加载mabatis.jar，junit.jar和其他环境包

创建SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
   <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <!-- 数据库连接 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="640913"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 加载映射文件 -->
    <mappers>
       <mapper resource="config/mapperDao/mapperStudent.xml"/>
    </mappers>
</configuration>

编写映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="mapperDao.StuMapperDao">
    <select id="findStuById" parameterType="int" resultType="domain.Student">
    <!-- parameterType输入参数类型  resultType输出类型java类对象 -->
        select * from student where id = #{id}
       </select>

    <select id="findStuByName" parameterType="java.lang.String" resultType="domain.Student">
    <!-- 根据名字模糊查找list 该方法会引入sql注入问题 -->
        SELECT * FROM student WHERE name LIKE '%${value}%'
       </select>

    <insert id="addStu" parameterType="domain.Student">
       <!--      SELECT LAST_INSERT_ID()得到刚插入用户的自增id；将id值赋予 keyProperty=类对象的属性名称 -->
               <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
            SELECT LAST_INSERT_ID()
               </selectKey>
       INSERT into student(name,qq,type,university,wish) VALUES(#{name},#{qq},#{type},#{university},#{wish})
       </insert>

    <delete id="deleteStuById" parameterType="java.lang.Integer">
        DELETE FROM student WHERE id=#{value}
       </delete>

    <update id="updateStu" parameterType="domain.Student">
        UPDATE student SET name=#{name},qq=#{qq},type=#{type},university=#{university},wish=#{wish} WHERE ID=#{id}
       </update>
</mapper>

编写接口：

原则：

映射文件mapper.xml中namespace等于接口的地址；

接口的方法名等于mapper.xml中statement id 名；

接口中方法的返回类型对应mapper.xml中方法的resultType，参数类型对应mapper.xml中方法的parameterType。

package mapperDao;

import domain.Student;

import java.util.List;

public interface StuMapperDao {
    public Student findStuById(int id) throws Exception;
    public List<Student> findStuByName(String name) throws Exception;
    public void addStu(Student student) throws Exception;
    public void deleteStuById(int id) throws Exception;
    public void updateStu(Student student) throws Exception;
}

用junit测试mapper接口

public class MapperTest {
    private SqlSessionFactory sqlSessionFactory;
    @Before
    public void setUp() throws Exception {
       String resource = "config/SqlMapConfig.xml";

        //得到配置文件流
        InputStream inputStream = Resources.getResourceAsStream(resource);

        //创建会话工厂
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

       @Test
    public void addTest() throws Exception {
       SqlSession sqlSession = sqlSessionFactory.openSession();
        StuMapperDao stuMapperDao = sqlSession.getMapper(StuMapperDao.class);
        Student student = new Student();
        student.setUniversity("mapper");
        student.setName("mapper name+");
        student.setQq(956324758);
        student.setType("mapper");
        student.setWish("get money+");

        stuMapperDao.addStu(student);
    }
       @Test
    public void delTest() throws Exception {
       SqlSession sqlSession = sqlSessionFactory.openSession();
        StuMapperDao stuMapperDao = sqlSession.getMapper(StuMapperDao.class);
        stuMapperDao.deleteStuById(11);
    }
       @Test
    public void updateTest() throws Exception {
       SqlSession sqlSession = sqlSessionFactory.openSession();
        StuMapperDao stuMapperDao = sqlSession.getMapper(StuMapperDao.class);
        Student student = new Student();
        student.setId(9);
        student.setUniversity("nmapper");
        student.setName("nmapper name");
        student.setQq(95632475);
        student.setType("nmapper");
        student.setWish("get money");
        stuMapperDao.updateStu(student);
    }
       @Test
    public void findTest() throws Exception {
       SqlSession sqlSession = sqlSessionFactory.openSession();
        StuMapperDao stuMapperDao = sqlSession.getMapper(StuMapperDao.class);
        Student student = stuMapperDao.findStuById(7);
    }
       @Test
    public void findListTest() throws Exception {
       SqlSession sqlSession = sqlSessionFactory.openSession();
        StuMapperDao stuMapperDao = sqlSession.getMapper(StuMapperDao.class);
        List<Student> list = stuMapperDao.findStuByName("mj");
        System.out.print(list);
    }

}