Mybatis环境搭建——注解和xml两种

使用xml文件搭建：

1.创建maven项目

2.连接数据库，时间不对的可以设置成

Asia/Shanghai

2.配置pom 注入所需依赖

<?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>org.example</groupId>
    <artifactId>mybatis_test1</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>

    </dependencies>
</project>

3.配置mybatis核心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>
<!--    配置环境-->
    <environments default="mysql">
<!--        配置mysql的和环境-->
        <environment id="mysql">
<!--            配置事务-->
            <transactionManager type="JDBC"></transactionManager>
<!--            配置连接池-->
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.jdbc.Driver"></property>
                    <property name="url" value="jdbc:mysql://localhost:3306/bobo?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf8"></property>
                    <property name="username" value="root"></property>
                    <property name="password" value="123456"></property>
                </dataSource>
        </environment>
    </environments>
<!--    配置映射文件的位置-->
    <mappers>
        <mapper resource="cn/bobo/IUserDao/IUserDao.xml"></mapper>  
    </mappers>
</configuration>

4.创建实体类user

package cn.bobo.User;

import java.io.Serializable;

public class User  implements Serializable {
    private  Integer id;
    private  String name;
    private  String pwd;

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

5.创建接口IUserDao

package cn.bobo.IUserDao;
import cn.bobo.UserDao.user;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface IUserDao {
//    @Select("select * from user")
    List<user> findall();
}

6.在resouorves中导入log4j.properties

log4j.rootLogger=debug, stdout, R

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n

log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=example.log

log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=5

log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n

7.测试类：

package cn.bobo;
import cn.bobo.IUserDao.IUserDao;
import cn.bobo.UserDao.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 org.junit.Test;

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

public class test1 {
    @Test
    public void testfindall() throws IOException {
//        1.读取配置文件，生成字节输入流
        InputStream in = Resources.getResourceAsStream("mybatis.xml");
//        2. 获取SqlSwssionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
//        3.获取SqlSession对象
        SqlSession sqlSession = factory.openSession();
//        4. 获取dao的代理对象
        IUserDao userDao = sqlSession.getMapper(IUserDao.class);
//        5. 执行查询所有方法
        List<user> users = userDao.findall();
        for (user user1 :users ){
            System.out.println(user1);
        }
//        6. 释放资源
        sqlSession.close();
        in.close();
    }
}

使用注解实现

与xml文件不同的是
1.接口中使用selec

xml中：

2.mapper映射不同
注解使用的是class

xml中