Mybatis框架中Mapper动态代理方式 _MyBatis框架

采得百花成蜜后，为谁辛苦为谁甜。这篇文章主要讲述Mybatis框架中Mapper动态代理方式相关的知识，希望能为你提供帮助。
开发规范：
mapper接口开发方法只需要程序猿编写mapper接口(相当于Dao接口)，
由Mybatis框架根据接口定义创建接口的动态代理对象，
代理对象的方法体跟Dao接口实现类方法相同。
Mapper接口开发需要遵循以下规范：
1.Mapper.xml文件中namespace与mapper接口的路径相同。
2.Mapper接口方法和Mapper.xml中定义的每个statement的id相同。
3.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。
4.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。
一、创建项目并导包：

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二、代码实现：
1.创建工具类：

package com.zsq.Utils; import java.io.IOException; import java.io.InputStream; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; public class Utils { /* * 原始方法获得数据库连接对象 */ public static Connection getConnection() throws SQLException, ClassNotFoundException{String driver = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/zengsiqi"; String username = "root"; String userpass = "123456"; Class.forName(driver); Connectioncon = DriverManager.getConnection(url, username, userpass); return con; } /* * mybatis操作数据库获得session的静态方法 */ public static SqlSession getSqlSession() throws IOException{String config = "mybatis-config.xml"; InputStream configStream = Resources.getResourceAsStream(config); SqlSessionFactoryBuilder buider = new SqlSessionFactoryBuilder(); SqlSessionFactory factory = buider.build(configStream); SqlSession session = factory.openSession(); return session; } }

2.搭建mybatis-config.xml文件
复制代码

< ?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"/> --> < environments default="development"> < environment id="development"> < transactionManager type="JDBC"/> < dataSource type="POOLED"> < property name="driver" value="https://www.songbingjia.com/android/com.mysql.jdbc.Driver"/> < property name="url" value="https://www.songbingjia.com/android/jdbc:mysql://localhost:3306/zengsiqi"/> < property name="username" value="https://www.songbingjia.com/android/root"/> < property name="password" value="https://www.songbingjia.com/android/123456"/> < /dataSource> < /environment> < /environments> < mappers> < mapper resource="com/zsq/sqlmap/MyInfoMapper.xml"/> < /mappers> < /configuration>

【Mybatis框架中Mapper动态代理方式】3.创建beans类：

package com.zsq.beans; import java.util.Date; /* * javaBean类： */ public class MyInfo { private int id; private String myname; private String sex; private int age; private String email; private String address; private Date brith; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getMyname() { return myname; } public void setMyname(String myname) { this.myname = myname; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public Date getBrith() { return brith; } public void setBrith(Date brith) { this.brith = brith; } public MyInfo() { } public MyInfo(int id, String myname, String sex, int age, String email, String address, Date brith) { this.id = id; this.myname = myname; this.sex = sex; this.age = age; this.email = email; this.address = address; this.brith = brith; } @Override public String toString() { return "MyInfo [id=" + id + ", myname=" + myname + ", sex=" + sex + ", age=" + age + ", email=" + email + ", address=" + address + ", brith=" + brith + "]"; } }

注意：类的属性、属性名与表的字段类型、字段名是一一对应的：

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4.写sql语句的xml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="com.zsq.mapper.MyInfoMapper"> < !-- 插入一行数据 --> < insert id="insert1" > insert into myinfo (id,myname,sex,age,email,address,brith) values (default,‘杨云飞‘,‘男‘,26,‘[email protected]‘,‘河南‘,‘1992-5-6‘) < /insert> < !-- 根据id查询 --> < select id="selectById" parameterType="Integer" resultType="com.zsq.beans.MyInfo"> select * from myinfo where id = #{id} < /select> < !-- 全查 --> < select id="selectAll" resultType="com.zsq.beans.MyInfo"> select * from myinfo order by id desc < /select> < !-- 模糊查询根据姓名查 --> < select id="findMyName" parameterType="String" resultType="com.zsq.beans.MyInfo"> select * from MyInfo where myname like "%"#{haha}"%" < /select> < !-- 根据id更新部门字段内容 --> < update id="updateById" parameterType="int"> update myinfo set age = 99 where id=#{id} < /update> < !-- 根据地址修改信息 --> < update id="updateById2" parameterType="String"> update myinfo set id = 7,myname = "曾志伟" where address = #{address} < /update> < !-- 根据id跟新参数传一个对象 --> < update id="updayeMyInfoById" parameterType="com.zsq.beans.MyInfo" > update myinfo set myname = #{myname},age = #{age}, sex = #{sex},email = #{email},address = #{address}, brith = #{brith} where id = #{id} < /update> < !-- 删除用户根据id删除 --> < delete id="delById" parameterType="int" > delete from myinfo where id = #{id} < /delete> < /mapper>

5.mapper接口：

package com.zsq.mapper; import java.util.Date; import java.util.List; import com.zsq.beans.MyInfo; //实现动态代理：只写接口，实现类由动态代理生成 public interface MyInfoMapper { /* *重点：必须遵循四个原则 *1> 方法名 == myInfo.xml 中的 id名 * 2> 返回值类型与MyIndoMapper.xml文件中的返回值类型要一致 * 3> 方法的入参类型要与MyInfoMapper.xml中入参的类型一致 * 4> 命名空间绑定此接口 */ //插入一行数据及内容是写死的 public int insert1(); //根据id查询方法 public MyInfo selectById(int id); //全查方法 public List< MyInfo> selectAll(); //模糊查询根据myname查的方法 public MyInfo findMyName(String myname); //根据id更新部门字段内容的方法 public int updateById(int id); //根据地址修改信息的方法 public int updateById2(String address); //根据id跟新参数传一个对象的方法 public int updayeMyInfoById(MyInfo user); //删除用户根据id删除的方法 public int delById(int id); }

6.test类：

package com.zsq.test; import java.util.Date; import java.util.List; import org.junit.Test; import com.zsq.Utils.Utils; import com.zsq.beans.MyInfo; import com.zsq.mapper.MyInfoMapper; import org.apache.ibatis.session.SqlSession; public class MyInfoMapperTest { @Test public void Test1() throws Exception { //获得session SqlSession session = Utils.getSqlSession(); /* * 1> session帮我生成一个实现类 * 2> 返回的还是接口，然后再调方法 */ MyInfoMapper info = session.getMapper(MyInfoMapper.class); /* 插入一行数据 int i = info.insert1(); System.out.println(i); *//*根据id查询 MyInfo selectById = info.selectById(5); System.out.println(selectById); *//* 全查 List< MyInfo> all = info.selectAll(); for (MyInfo myInfo : all) { System.out.println(myInfo); }*//*模糊查询根据姓名查 MyInfo info2 = info.findMyName("云"); System.out.println(info2); System.out.println(info2.getMyname()); *//*根据id更新部门字段内容 int id = info.updateById(3333); System.out.println(id); *//*根据地址修改信息 int id2 = info.updateById2("莲花乡"); System.out.println(id2); *//*根据id跟新参数传一个对象 MyInfo user = new MyInfo(); user.setId(3350); user.setMyname("曾志伟 "); user.setSex("女"); user.setAge(2323); user.setEmail("[email protected]"); user.setAddress("西城"); user.setBrith(new Date()); int t1 = info.updayeMyInfoById(user); System.out.println(t1); *///删除用户根据id删除 int t1 = info.delById(3353); System.out.println(t1); //id为3353的删除session.commit(); session.close(); } }