Mapper动态代理开发

在开发的过程中只需要写Dao层的借口，无需写其实现类，实现类有框架自己补充。
框架是根据mapper文件自动补充的，因此需要满足下面四个条件
Mapper接口开发需要遵循以下规范：

- Mapper.xml文件中的namespace与mapper接口的类路径相同。
- Mapper接口方法名和Mapper.xml中定义的每个statement的id相同
- Mapper接口方法的输入参数类型和mapper.xml中定义的每个sql 的parameterType的类型相同
- Mapper接口方法的输出参数类型和mapper.xml中定义的每个sql的resultType的类型相同

1，数据库

create table STUDENT ( STU_ID VARCHAR2(11) not null, STU_NAME VARCHAR2(50), STU_BIRTHDATE DATE, STU_PHONE VARCHAR2(50) )

2，pojo

package com.songyan.pojo; import java.util.Date; import java.lang.String; public class Student { private String stuId; private String stuName; private Date stuBirthdate; private String stuPhone; public String getStuId() { return stuId; } public void setStuId(String stuId) { this.stuId = stuId; } public String getStuName() { return stuName; } public void setStuName(String stuName) { this.stuName = stuName; } public Date getStuBirthdate() { return stuBirthdate; } public void setStuBirthdate(Date stuBirthdate) { this.stuBirthdate = stuBirthdate; } public String getStuPhone() { return stuPhone; } public void setStuPhone(String stuPhone) { this.stuPhone = stuPhone; } @Override public String toString() { return "student:"+this.stuId+"  "+this.stuName; } }

3，dao

package com.songyan.dao; import java.util.List; import com.songyan.pojo.Student; public interface StudentMapper { public void insertStudent(Student student); public void deteteStudent(String id); public void updateStudent(Student student); public List<Student> selectStudent(String id); }

4，xml

<?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">
<!-- 设置命名空间 -->
<mapper namespace="com.songyan.dao.StudentMapper">
    <resultMap type="student" id="BaseResultMap">
        <id column="STU_ID" property="stuId" javaType="java.lang.String" jdbcType="VARCHAR" />
        <result column="STU_NAME" property="stuName" javaType="java.lang.String" jdbcType="VARCHAR" />
        <result column="STU_BIRTHDATE" property="stuBirthdate" javaType="java.util.Date" jdbcType="DATE" />
        <result column="STU_PHONE" property="stuPhone" javaType="java.lang.String" jdbcType="VARCHAR" />
    </resultMap>
    <select id="selectStudent" parameterType="String" resultType="com.songyan.pojo.Student"> select * from student where STU_ID= #{stuId} </select>
    <insert id="insertStudent" parameterType="student" > insert into student(STU_ID,STU_NAME,STU_PHONE) values(#{stuId},#{stuName},#{stuPhone}) </insert>
    
    <delete id="deteteStudent" parameterType="String"> delete from student where STU_ID= #{stuId} </delete>
    
    <update id="updateStudent" parameterType="String"> update student set STU_NAME=#{stuName} where STU_ID = #{stuId} </update>
</mapper>

5，核心配置文件

<?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>
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>
    <typeAliases>
        <typeAlias type="com.songyan.pojo.Student" alias="student" />
    </typeAliases>
    <!--配置环境，默认的环境id为oracle -->
    <environments default="oracle">
        <!-- 配置环境为oracle的环境 -->
        <environment id="oracle">
            <!--使用JDBC的事务处理 -->
            <transactionManager type="JDBC" />
            <!--数据库连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver"></property>
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:inspur"></property>
                <property name="username" value="scott"></property>
                <property name="password" value="tiger"></property>
            </dataSource>
        </environment>
    </environments>
    <!--配置mapper的位置 -->
    <mappers>
        <mapper resource="com/songyan/dao/studentMapper.xml" />
    </mappers>
</configuration>

6，log4j

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p [%t] %c{1}:%L - %m%n
#\u5728\u5F00\u53D1\u73AF\u5883\u4E0B\u65E5\u5FD7\u7EA7\u522B\u8981\u8BBE\u7F6E\u6210DEBUG\uFF0C\u751F\u4EA7\u73AF\u5883\u8BBE\u7F6E\u6210info\u6216error
log4j.rootLogger=DEBUG, stdout
#log4j.rootLogger=stdout

7,测试类

package com.songyan.client; import java.io.IOException; import java.io.InputStream; import java.util.List; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import org.junit.Test; import com.songyan.dao.StudentMapper; import com.songyan.pojo.Student; public class Client { @Test public void testInsert() throws IOException { //读取配置信息
    String resource="applicationContext.xml"; //根据配置文件构建sqlsessionFactory
    InputStream in=Resources.getResourceAsStream(resource); //通过sqlsessionFactory创建sqlsession
    SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(in); SqlSession sqlSession =sqlSessionFactory.openSession(); //创建一个学生对象
    Student student =new Student(); student.setStuId("1"); student.setStuName("tom"); student.setStuPhone("111"); //获取接口类
    StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class); studentMapper.insertStudent(student); //输出结果
 sqlSession.commit(); sqlSession.close(); } @Test public void testDelete() throws IOException { //读取配置信息
    String resource="applicationContext.xml"; //根据配置文件构建sqlsessionFactory
    InputStream in=Resources.getResourceAsStream(resource); //通过sqlsessionFactory创建sqlsession
    SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(in); SqlSession sqlSession =sqlSessionFactory.openSession(); //获取接口类
    StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class); studentMapper.deteteStudent("1"); sqlSession.commit(); sqlSession.close(); } @Test public void testUpdate() throws IOException { //读取配置信息
    String resource="applicationContext.xml"; //根据配置文件构建sqlsessionFactory
    InputStream in=Resources.getResourceAsStream(resource); //通过sqlsessionFactory创建sqlsession
    SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(in); SqlSession sqlSession =sqlSessionFactory.openSession(); //创建一个学生对象
    Student student =new Student(); student.setStuId("2"); student.setStuName("tofm"); student.setStuPhone("111"); //获取接口类
    StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class); studentMapper.updateStudent(student); sqlSession.commit(); sqlSession.close(); } @Test public void testSelect() throws IOException { //读取配置信息
    String resource="applicationContext.xml"; //根据配置文件构建sqlsessionFactory
    InputStream in=Resources.getResourceAsStream(resource); //通过sqlsessionFactory创建sqlsession
    SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(in); SqlSession sqlSession =sqlSessionFactory.openSession(); //获取接口类
    StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class); List<Student> relstu=studentMapper.selectStudent("2"); System.out.println(relstu.toString()); //输出结果
    for(Student stu : relstu) { System.out.println(stu); } sqlSession.close(); } }

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