Mybatis入門案例

Mybatis入門案例

1.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">
<!--mybatis的主配置文件 -->
<configuration>
    <!--配置環境-->
<environments default="mysql">
    <!--配置mysql的環境-->
    <environment id="mysql">
        <!--配置事務的類型-->
        <transactionManager type="JDBC"></transactionManager>
         <!--配置數據源（連接池）-->
        <dataSource type="POOLED">
            <!--配置連接數據庫的4個基本信息-->
            <property name="driver" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/eesy"/>
            <property name="username" value="root"/>
            <property name="password" value="123456"/>
        </dataSource>
    </environment>
</environments>
<!--指定映射配置文件的位置，映射配置文件指的是每個dao獨立的配置文件-->
    <mappers>
        <mapper resource="com/itcast/dao/IUserDao.xml"/>
    </mappers>
<!--    <mappers>  &lt;!&ndash;全限定類名&ndash;&gt;
        <mapper class="com.itcast.dao.IUserDao"/>
    </mappers>-->
</configuration>

 

2.log4j.properties 配置文件

### 設置###
log4j.rootLogger = debug,stdout,D,E

### 輸出信息到控制擡 ###
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 = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

### 輸出DEBUG 級別以上的日誌到=E://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File =  C://Users//cs//Desktop/log.log 
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

### 輸出ERROR 級別以上的日誌到=E://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = C://Users//cs//Desktop/error.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR 
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

3.User 類

package com.itcast.domin;


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


public class User implements Serializable {
    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 + '\'' +
                '}';
    }
}

 

4.IUserDao 接口

package com.itcast.dao;

import com.itcast.domin.User;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 *
 * 用戶持久層接口
 */
public interface IUserDao {
    /**
     * 查詢所有操作
     * @return
     */
 /*  @Select("select * from user")*/
    List<User> findAll();
}

 

5.IUserDao配置文件

<?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.itcast.dao.IUserDao">
    <!--配置查詢所有-->
    <select id="findAll" resultType="com.itcast.domin.User">
        select * from user
    </select>

</mapper>

 

6.MybatisTest 測試類

package com.itcast.test;

import com.itcast.dao.IUserDao;
import com.itcast.domin.User;
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 java.io.InputStream;
import java.util.List;

public class MybatisTset {
    /**
     * 入門案例
     */
    public static void main(String[] args) throws Exception {
        //1.讀取配置文件
        InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
       //2.創建SqlSeesionFactory工廠
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory factory=builder.build(in);
        //3.使用工廠生產SqlSession對象
        SqlSession session=factory.openSession();
        //4.使用SqlSession 創建Dao接口的代理對象
        IUserDao userDao=session.getMapper(IUserDao.class);
        //5.使用代理對象執行方法
        List<User> users=userDao.findAll();
        for (User user:users){
            System.out.println(user);
        }
        //6.釋放資源
        session.close();
        in.close();

    }
}

 

7.補充： 建立數據庫

CREATE DATABASE eesy;
SELECT * FROM user

INSERT INTO user VALUES(41,'老王','2019-11-28 3:34:23','男','北京'),(42,'小二王','2019-11-26 13:56:27','男','北京金燕龍'),
(43,'老二王','2019-11-24 18:29:53','女','北京金燕龍'),(44,'西安交大','2019-11-21 23:44:13','男','北京金燕龍'),
(45,'老王','2019-11-28 3:34:23','男','北京'),(48,'小馬寶莉','2019-11-28 22:33:13','男','北京修正');