01.基于IDEA搭建mybatis的MAVEN项目

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基础环境

• IDEA
  
  
• MAVEN

工程目录

MySQL数据库

Maven Pom

添加mybatis以及mysql的依赖包

    4.0.0

    com.mu
    mybatis
    1.0-SNAPSHOT

    
        
            org.mybatis
            mybatis
            3.4.1
        
        
            mysql
            mysql-connector-java
            5.1.29
        
    
    
        
        
           
                src/main/resources
                
                    **/*.properties
                    **/*.xml
                    **/*.tld
                
                false
            
            
                src/main/java
                
                    **/*.properties
                    **/*.xml
                    **/*.tld
                
                false
            
        
    

创建各实体类以及mapper.xml文件

• User.java

package com.mu.mybatis.domain;

/**
 * Created by manunited1985 on 2017/11/23.
 */
public class User {
    private Integer userId;
    private String userName;
    private String userPassword;
    private String userEmail;

    public User(Integer userId, String userName, String userPassword, String userEmail) {
        this.userId = userId;
        this.userName = userName;
        this.userPassword = userPassword;
        this.userEmail = userEmail;
    }

    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 String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    public String getUserEmail() {
        return userEmail;
    }

    public void setUserEmail(String userEmail) {
        this.userEmail = userEmail;
    }

    @Override
    public String toString() {
        return "User [userId=" + userId + ", userName=" + userName
                + ", userPassword=" + userPassword + ", userEmail=" + userEmail
                + "]";
    }
}

• UserMapper.java

package com.mu.mybatis.mapper;
import com.mu.mybatis.domain.User;

/**
 * Created by manunited1985 on 2017/11/24.
 */
public interface UserMapper {
    public User selectUserById(Integer userId);
    public List selectUserAll();
    public void insertUser(User user);
}

• UserMapper.xml

    
    
        
        
        
        
    
    
    
        SELECT * FROM t_user WHERE USER_ID = #{userId}
    
         
    
        SELECT * FROM t_user
    
     
    
        insert into t_user (USER_ID,USER_NAME,USER_PASSWORD,USER_EMAIL)
        values (#{userId},#{userName},#{userPassword},#{userEmail})
    

• Main.java

package com.mu.mybatis;

import com.mu.mybatis.domain.User;
import com.mu.mybatis.mapper.UserMapper;
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.io.IOException;
import java.util.List;

/**
 * Created by manunited1985 on 2017/11/23.
 */
public class Main {

    public static void main(String[] args) throws IOException {

        SqlSession session = null;

        try {
            // 读取配置信息
            String resource = "application.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();

            // 选择不同的环境
            String env = "product";
            SqlSessionFactory factory = builder.build(inputStream,env);

            // 产生SqlSession对象
            session = factory.openSession();
            System.out.println(session);

            // 获取映射对象            
            UserMapper userMapper = session.getMapper(UserMapper.class);

            // 获取id为1的账户
            User user = userMapper.selectUserById(1);
            System.out.println(user);

            // 获取所有账户
            List arrayList = userMapper.selectUserAll();
            System.out.println(arrayList);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (session != null)
                // 关闭连接
                session.close();
        }

    }
}

数据库配置 jdbc.properties

jdbc_driver=com.mysql.jdbc.Driver
jdbc_url=jdbc\:mysql\://127.0.0.1\:3306/test?useUnicode=true&characterEncoding=utf-8
jdbc_username=root
jdbc_password=123456

应用配置application.xml

运行结果

org.apache.ibatis.session.defaults.DefaultSqlSession@454b70a9
User [userId=1, userName=xiaoming, userPassword=123456, userEmail=x@sina.com]
[User [userId=1, userName=xiaoming, userPassword=123456, userEmail=x@sina.com], User [userId=2, userName=tom, userPassword=123, userEmail=tom@sina.com], User [userId=3, userName=jack, userPassword=123, userEmail=jack@sina.com]]

备注

如果你利用IDEA创建的工程,在加载mapper.xml文件的时候,出现类似现象:

mybatis错误——java.io.IOException: Could not find resource com/xxx/xxxMapper.xml

那么,你可以在pom.xml文件的添加如下字段:

 
        
        
            
                src/main/java
                
                    **/*.xml
                
            
        
    

IDEA是不会编译src的java目录的xml文件，所以在Mybatis的配置文件中找不到xml文件！（也有可能是Maven构建项目的问题，网上教程很多项目是普通的Java web项目，所以可以放到src下面也能读取到）