Java MyBatis3（2） Mapper代理的开发方式
Mapper代理的开发规范
1、 mapper接口的全限定名要和mapper映射文件的namespace值一致。
2、 mapper接口的方法名称要和mapper映射文件的statement的id一致。
3、 mapper接口的方法参数类型要和mapper映射文件的statement的parameterType的值一致，而且它的参数是一个。
4、 mapper接口的方法返回值类型要和mapper映射文件的statement的resultType的值一致。
代码实战
1.搭建如下工程
2.mapper接口——interface UserMapper
package com.mf.mybatis.mapper; import java.util.List; import com.mf.mybatis.po.User; import com.mf.mybatis.po.UserQueryVO; public interface UserMapper { public User findUserById(int id) throws Exception; public void insertUser(User user) throws Exception; public List<User> findUserList(UserQueryVO vo); public int findUserCount(UserQueryVO vo); public User findUserRstMap(int id); }
3.mapper映射文件——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> <properties resource="db.properties"> <property name="db.username" value="123" /> </properties> <typeAliases> <typeAlias type="com.mf.mybatis.po.User" alias="user"/> <package name="com.mf.mybatis.po" /> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="${db.driver}" /> <property name="url" value="${db.url}" /> <property name="username" value="${db.username}" /> <property name="password" value="${db.password}" /> </dataSource> </environment> </environments> <mappers> <!--<mapper resource="mapper/UserMapper.xml" /> --> <package name="com.mf.mybatis.mapper" /> </mappers> </configuration>
4.Db.properties
db.driver=com.mysql.jdbc.Driver db.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8 db.username=root db.password=root
5.log4j.properties
# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# 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
6.UserMapper.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"> <mapper namespace="com.mf.mybatis.mapper.UserMapper"> <select id="findUserById" parameterType="int" resultType="User"> SELECT * FROM USER WHERE id =#{id} </select> <insert id="insertUser" parameterType="com.mf.mybatis.po.User"> <selectKey keyProperty="id" resultType="int" order="AFTER"> SELECT LAST_INSERT_ID() </selectKey> INSERT INTO USER(username,birthday,sex,address) VALUES(#{username},#{birthday},#{sex},#{address}) </insert> <sql id="whereClause"> <if test="user != null"> <if test="user.username != null and user.username != ''"> AND username LIKE '%${user.username}%' </if> <if test="user.sex != null and user.sex != ''"> AND sex = #{user.sex} </if> </if> <if test="idList != null"> AND id IN <foreach collection="idList" item="id" open="(" close=")" separator=","> #{id} </foreach> </if> </sql> <select id="findUserList" parameterType="com.mf.mybatis.po.UserQueryVO" resultType="user"> SELECT * FROM user <where> <include refid="whereClause" /> </where> </select> <select id="findUserCount" parameterType="com.mf.mybatis.po.UserQueryVO" resultType="int"> SELECT count(*) FROM user <where> <include refid="whereClause" /> </where> </select> <resultMap type="user" id="UserRstMap"> <id column="id_" property="id" /> <result column="username_" property="username" /> <result column="sex_" property="sex" /> </resultMap> <select id="findUserRstMap" parameterType="int" resultMap="UserRstMap"> Select id id_,username username_,sex sex_ from user where id = #{id} </select> </mapper>
7.UserQueryVO.java
package com.mf.mybatis.po; import java.util.List; public class UserQueryVO { private User user; private List<Integer> idList; public List<Integer> getIdList() { return idList; } public void setIdList(List<Integer> idList) { this.idList = idList; } public User getUser() { return user; } public void setUser(User user) { this.user = user; } }
8.UserMapperTest.java
package com.mf.mybatis.mapper; import java.io.InputStream; import java.util.ArrayList; 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.Before; import org.junit.Test; import com.mf.mybatis.po.User; import com.mf.mybatis.po.UserQueryVO; public class UserMapperTest { private SqlSessionFactory sqlSessionFactory; @Before public void setUp() throws Exception { String resource = "SqlMapConfig.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); } @Test public void testFindUserById() throws Exception { SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.findUserById(1); System.out.println(user); sqlSession.close(); } @Test public void testInsertUser() throws Exception { SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = new User(); user.setUsername("sgz"); user.setAddress("北京"); mapper.insertUser(user); System.out.println(user.getId()); sqlSession.commit(); sqlSession.close(); } @Test public void testFindUserList() throws Exception { SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); UserQueryVO vo = new UserQueryVO(); // User user= new User(); // user.setUsername("沐风"); // user.setSex("1"); // vo.setUser(user); List<Integer> idList = new ArrayList<>(); idList.add(1); idList.add(2); idList.add(10); vo.setIdList(idList); List<User> list = mapper.findUserList(vo); int count = mapper.findUserCount(vo); System.out.println(list); System.out.println(count); sqlSession.close(); } @Test public void testFindUserRstMap() throws Exception { SqlSession sqlSession = sqlSessionFactory.openSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.findUserRstMap(1); System.out.println(user); sqlSession.close(); } }
