Mybatis学习笔记------mybatis的CRUD(基于dao代理)

实例

pom.xml文件配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.xyc</groupId>
    <artifactId>MyBatis_Demo1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.15</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
</project>

log4j.properties文件配置

# Set root category to INFO and its only appender to CONSOLE.
# log4j.rootCategory=INFO,CONSOLE     debug info warn error fatal
log4j.rootCategory=debug, CONSOLE, LOGFILE

#Set the enterprise logger category to FATAL and its only appender to CONSOLE.
log4j.logger.org.apache.axis.enterprise=FATAL, CONSOLE

#CONSOLE is set to be a ConsoleAppender using a Patternlayout.
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x - %m/n

#LOGFILE is set to be a File appender using a PatternLayout.
log4j.appender.LOGFILE=org.apache.log4j.FileAppender
log4j.appender.LOGFILE.File=g:\axis.log
log4j.appender.LOGFILE.Append=true
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%d{ISO8601} %-6r [%15.15t] %-5p %30.30c %x -%m/n

SqlMapConfig.xml文件配置

<?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>
<!--    配置properties
        可以在标签内部配置连接数据库的信息,也可以通过属性引用外部配置文件信息
        resource属性: (常用属性)
            用于指定配置文件的位置,是按照类路径的写法来写的,并且必须存在于类路径下.
        url属性:
            要求按照url的写法来写地址
            URL: Uniform Resource Locator 统一资源定位符. 它是可以唯一标识一个资源的位置
                写法: http://localhost:8080/mybatisserver/demo1Servlet
-->
    <!-- <properties resource="" url="">
        <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="991016"/>
    </properties>-->

<!--    使用typeAliases配置别名,他只能配置domain中类的别名-->
    <!--   <typeAliases>
            typeAlias用于配置别名,type属性指定的是实体类的全限定类名,alias属性指定别名,当制定了别名就不再区分大小写
            <typeAlias type="com.xyc.domain.User" alias="user"></typeAlias>
            用于指定要配置别名的包,当指定之后,该包下的实体类都会注册别名,并且类名就是别名,不再区分大小写
            <package name="com.xyc.domain"/>
    </typeAliases>-->

    <!--    配置环境-->
    <environments default="mysql">
<!--        mysql的环境配置-->
        <environment id="mysql">
<!--            配置事务类型-->
            <transactionManager type="JDBC"/>
<!--            配置连接池-->
            <dataSource type="POOLED">
<!--                配置来连接数据库的基本信息-->
                <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="991016"/>
            </dataSource>
        </environment>
    </environments>
<!--    指定映射配置文件的位置,映射配置文件指的是每个dao独立的配置文件
           如果是用注解来配置的话,此处应该使用class属性指定注解的dao全限定类名,并在
-->
    <mappers>
        <mapper resource="com/xyc/dao/IUserDao.xml" />
<!--        package标签是用于指定dao接口所在的包 ,制定之后就不用写mapper以及resource和class了-->
    </mappers>
</configuration>

User类

package com.xyc.domain;

import com.sun.xml.internal.bind.v2.model.core.ID;

import java.util.Date;

/**
 * @Author: 薛云冲
 * Created on 2019/7/25 22:46
 */
public class User {
    private Integer id;
    private String username;
    private Date birthday;
    private String sex;
    private String address;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", birthday=" + birthday +
                ", sex='" + sex + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

IUserDao 接口

package com.xyc.dao;

import com.sun.org.apache.xml.internal.security.Init;
import com.xyc.domain.User;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 * @Author: 薛云冲
 * 用户持久层接口
 * Created on 2019/7/25 22:49
 */
public interface IUserDao {
    /**
     * 查询所有操作
     */
    //@Select("select * from user ")
    List<User> findAll();

    /**
     * 保存用户操作
     */
    boolean saveUser(User user);

    /**
     *  更新用户操作
     * @param user
     */
    boolean updateUser(User user);

    /**
     * 根据id删除用户信息操作
     * @param userId
     */
    boolean deleteUser(int userId);

    /**
     *  根据id查询用户信息
     */
    User findById(int userId);

    /**
     * 根据名称模糊查询用户信息 like
     * 注意在模糊查询时 传的 字符串前后 需手动加入"%"
     */
    List<User>findByUserame(String username);

    /**
     * 用聚合函数查询总人数
     **/
    int findTotal();
}

IUserDao接口的映射文件IUserDao.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.xyc.dao.IUserDao">
<!--    配置查询所有-->
    <select id="findAll" resultType="com.xyc.domain.User">
    select * from user;
  </select>
<!--    配置根据id查询用户信息-->
    <select id="findById" parameterType="int" resultType="com.xyc.domain.User">
        SELECT * from user where id=#{id};
    </select>
<!--    配置根据username模糊查询用户信息-->
    <select id="findByUserame" resultType="com.xyc.domain.User" parameterType="String">
        select * from user where username like #{username};
    </select>
<!--    配置使用聚合函数查询总人数-->
    <select id="findTotal" resultType="int">
        select count(id) from user;
    </select>
<!--    配置保存用户-->
    <insert id="saveUser" parameterType="com.xyc.domain.User">
    insert into user(username,address,sex,birthday) values(#{username},#{address},#{sex},#{birthday});
    </insert>
<!--    配置更新用户-->
    <update id="updateUser" parameterType="com.xyc.domain.User">
        update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id=#{id};
    </update>
<!--    配置删除用户-->
    <delete id="deleteUser" parameterType="int">
        delete from user where id=#{id};
    </delete>

</mapper>

测试类MybatisTest.java

package com.xyc.test;

import com.mysql.cj.Session;
import com.sun.xml.internal.bind.v2.model.core.ID;
import com.xyc.dao.IUserDao;

import com.xyc.domain.User;
import junit.framework.ComparisonCompactor;
import org.apache.ibatis.annotations.Select;
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.hamcrest.Factory;
import org.junit.Test;
import org.junit.validator.PublicClassValidator;
import sun.rmi.server.UnicastServerRef;

import javax.swing.plaf.SplitPaneUI;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

/**
 * @Author: 薛云冲
 * Created on 2019/7/26 9:58
 * mybatis 的入门案例
 */
public class MybatisTest {
    @Test
//    查询所有操作
    public void testFindAll() throws IOException {
        //1.读取配置文件
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建SqlSessionFactory工厂
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(inputStream);
        //3.使用工厂生产SqlSession对象
        SqlSession sqlSession = factory.openSession();
        //4.使用SqlSession创建Dao接口的代理对象(当dao接口实现类自写时就不用生成代理对象了,使用自己实现的类即可)
        IUserDao userDao = sqlSession.getMapper(IUserDao.class);
            //使用自写的dao实现类时
            //UserDaoImpl userDao = new UserDaoImpl(factory);
        //5.使用代理对象执行方法
        List<User> users = userDao.findAll();
        //6.处理数据
            System.out.println("");
        for (User user : users) {
            System.out.println(user);
        }
        //7.释放资源
        sqlSession.close();
        inputStream.close();
    }

    @Test
//    测试保存操作
    public void testSaveUser() throws IOException {
        User user=new User();
        user.setUsername("鲁班七号");
        user.setSex("男");
        user.setBirthday(new Date());
        user.setAddress("召唤师峡谷");
        //读取配置文件,生成字节输出流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //获取SqlSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession session = factory.openSession();
        //获取dao的代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //保存User
        mapper.saveUser(user);

        //提交事务
        session.commit();
        //释放资源
        session.close();
        inputStream.close();
    }
    @Test
//    测试更新操作
    public void testUpdate() throws IOException {
        User user = new User();
        user.setId(6);
        user.setUsername("鲁班七号");
        user.setAddress("王者峡谷");
        user.setBirthday(new Date());
        user.setSex("男");


        //读取配置文件,生成字节输出流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //获取SqlSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession session = factory.openSession();
        //获取dao的代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //修改User
        mapper.updateUser(user);
        //提价事务
        session.commit();

        //释放资源
        session.close();
        inputStream.close();

    }
    @Test
    //测试删除User信息操作
    public void testDeleteUser() throws IOException {

        int userId = 9;

        //读取配置文件,获取字节输出资源流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //获取SqlSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession session = factory.openSession();
        //获取dao代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //删除User
        mapper.deleteUser(userId);
        //提交事务
        session.commit();
        //关闭对象
        session.close();
        inputStream.close();
    }
    @Test
    //测试根据id查询User信息
    public void testFindById() throws IOException {
        int userId=3;
        //读取配置文件,获取字节输出资源流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //获取SqlSessionFactoryBuilder
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取SqlSession对象
        SqlSession session = factory.openSession();
        //获取dao代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //查询User信息
        User user = mapper.findById(userId);
        System.out.println();
        System.out.println(user);
        //释放资源
        session.close();
        inputStream.close();
    }
    @Test
    //根据Username查询User信息
    public void testFindByUsername() throws IOException {

        String username = "七";
        //读取配置文件,获取字节输出资源流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //创建SplSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //创建SqlSession对象
        SqlSession session = factory.openSession();
        //创建dao代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //查询User信息
        List<User> users = mapper.findByUserame("%"+username+"%");

        System.out.println();
        for (User user : users) {
            System.out.println(user);
        }
        //释放资源
        session.close();
        inputStream.close();
    }
    @Test
    //通过聚合函数查询总人数
    public void testFindTotal() throws IOException {
        //读取配置文件,获取字节输出资源流
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //创建SqlSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
        //创建SqlSession对象
        SqlSession session = factory.openSession();
        //创建dao代理对象
        IUserDao mapper = session.getMapper(IUserDao.class);
        //查询总人数
        int total = mapper.findTotal();
        System.out.println();
        System.out.println(total);
        //释放资源
        session.close();
        inputStream.close();

    }
}