mybatis实体类与数据库字段映射

mybatis实体类与数据库字段映射

1.pom

<?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.lq</groupId>
    <artifactId>mybatis-annotation</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>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
    </dependencies>

</project>

2.UserDao

package com.lq.dao;

import com.lq.domain.User;
import com.lq.domain.User1;
import org.apache.ibatis.annotations.*;

import java.util.List;

/**
 * @ProjectName: mybatis-annotation
 * @Package: com.lq.dao
 * @ClassName: UserDao
 * @Author: liqiang
 * @Date: 2020/2/20 0020 17:46
 * @Version: 1.0
 */
public interface UserDao {
    @Select(value = "select * from user")
    @Results(id="userMap",value={
            @Result(id=true,column = "id",property = "userId"),
            @Result(column = "username",property = "userName"),
            @Result(column = "address",property = "userAddress"),
            @Result(column = "sex",property = "userSex"),
            @Result(column = "birthday",property = "userBirthday")})
    List<User1> findAll();

    @Select("select * from user  where id=#{id} ")
    @ResultMap(value = {"userMap"})
    User1 findById(Integer userId);

    @Select("select * from user where username like #{username} ")
    @ResultMap(value = {"userMap"})
    List<User1> findUserByName(String username);
}

3.User1

package com.lq.domain;

import java.io.Serializable;
import java.util.Date;

/**
 * @ProjectName: mybatis-annotation
 * @Package: com.lq.domain
 * @ClassName: User
 * @Author: liqiang
 * @Date: 2020/2/20 0020 17:40
 * @Version: 1.0
 */
public class User1 implements Serializable {
    private Integer userId;
    private String userName;
    private Date userBirthday;
    private String userSex;
    private String userAddress;

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Date getUserBirthday() {
        return userBirthday;
    }

    public void setUserBirthday(Date userBirthday) {
        this.userBirthday = userBirthday;
    }

    public String getUserSex() {
        return userSex;
    }

    public void setUserSex(String userSex) {
        this.userSex = userSex;
    }

    public String getUserAddress() {
        return userAddress;
    }

    public void setUserAddress(String userAddress) {
        this.userAddress = userAddress;
    }

    @Override
    public String toString() {
        return "User1{" +
                "userId=" + userId +
                ", userName='" + userName + '\'' +
                ", userBirthday=" + userBirthday +
                ", userSex='" + userSex + '\'' +
                ", userAddress='" + userAddress + '\'' +
                '}';
    }
}

4.jdbcConfig.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/eesy
jdbc.username=root
jdbc.password=root

5.log4j.properties

# Set root category priority 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=d:\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

6.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>
    <!-- 配置properties-->
    <properties resource="jdbcConfig.properties"></properties>
    <!--设置懒加载-->
    <settings>
        <setting name="lazyLoadingEnabled" value="true"/>
        <setting name="aggressiveLazyLoading" value="false"/>
    </settings>
    <!--使用typeAliases配置别名，它只能配置domain中类的别名 -->
    <typeAliases>
        <package name="com.lq.domain"></package>
    </typeAliases>

    <!--配置环境-->
    <environments default="mysql">
        <!-- 配置mysql的环境-->
        <environment id="mysql">
            <!-- 配置事务 -->
            <transactionManager type="JDBC"></transactionManager>

            <!--配置连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"></property>
                <property name="url" value="${jdbc.url}"></property>
                <property name="username" value="${jdbc.username}"></property>
                <property name="password" value="${jdbc.password}"></property>
            </dataSource>
        </environment>
    </environments>
    <!-- 配置映射文件的位置 -->
    <mappers>
        <package name="com.lq.dao"></package>
    </mappers>
</configuration>

7.MyTest

package com.lq.test;

import com.lq.dao.UserDao;
import com.lq.domain.User;
import com.lq.domain.User1;
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.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

/**
 * @ProjectName: mybatis-annotation
 * @Package: com.lq.test
 * @ClassName: MyTest
 * @Author: liqiang
 * @Date: 2020/2/20 0020 17:57
 * @Version: 1.0
 */
public class MyTest {
    private InputStream inputStream;
    private SqlSessionFactory factory;
    private SqlSession sqlSession;
    private UserDao userDao;
    @Before
    public void init() throws Exception{
        //1.获取字节输入流
        inputStream = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.根据字节输入流构建sqlSessionFactory
        factory = new SqlSessionFactoryBuilder().build(inputStream);
        //3.sqlSessionFactory生产一个sqlSession
        sqlSession = factory.openSession();
        //4.使用sqlSession获取dao的代理对象
        userDao = sqlSession.getMapper(UserDao.class);
    }
    @After
    public void destroy() throws IOException {
        sqlSession.commit();
        //6.释放资源
        sqlSession.close();
        inputStream.close();
    }
    @Test
    public void testFindAll(){
        List<User1> users = userDao.findAll();
        for (User1 user : users) {
            System.out.println(user);
        }
    }
    @Test
    public void FindById(){
        User1 user = userDao.findById(50);
        System.out.println(user);
    }
    @Test
    public void FindByName(){
        List<User1> users = userDao.findUserByName("王");
        for (User1 user : users) {
            System.out.println(user);
        }
    }
}