mybatis笔记<一> Demo-白红宇

mybatis笔记<一> Demo

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发布时间：2019-06-14

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mybatis作为一个orm互联网公司基本都在用，今天写个笔记。记录一下mybatis使用

参考官网：

这里使用的mysql，建了一个数据库db_test，表person，字段id, name, age。插了一条数据，id为1。demo 主要功能从mysql中读取这条记录。

mybatis主要通过读取配置文件xml，初始化得到SqlSessionFactory，通过facotry拿到session，然后操作数据库。这里具体还要看下源码，后面在做个笔记记录一下。

同时会写下集成spring后的用法

代码：

pom.xml


     
         
      
       4.0.0
          
      
       com.gxf.mybatis
          
      
       demo
          
      
       1.0-SNAPSHOT
          
              
                   
        
         org.mybatis
                    
        
         mybatis
                    
        
         3.4.6
                
               
                   
        
         mysql
                    
        
         mysql-connector-java
                    
        
         8.0.11

mybatis-config.xml

Person.java

package com.gxf.mybatis.util;public class Person {    private int id;    private String name;    private int age;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    @Override    public String toString() {        return "Person{" +                "id=" + id +                ", name='" + name + '\'' +                ", age=" + age +                '}';    }}

PersonMapper.java

package com.gxf.mybatis.mapper;import com.gxf.mybatis.util.Person;public interface PersonMapper {    Person selectPerson(int id);}

PersonMapper1.java

package com.gxf.mybatis.mapper;import com.gxf.mybatis.util.Person;import org.apache.ibatis.annotations.Select;public interface PersonMapper1 {    @Select("SELECT * FROM person WHERE id = #{idss}")    Person selectPerson(int idss);}

SqlSessionFactoryHelper.java

package com.gxf.mybatis.util;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import java.io.InputStream;public class SqlSessionFactoryHelper {    public static SqlSessionFactory getSqlSessionFactory() {        SqlSessionFactory sqlSessionFactory = null;        try{            String resource = "mybatis-config.xml";            InputStream inputStream = Resources.getResourceAsStream(resource);            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);        }catch (Exception e){            e.printStackTrace();        }        return sqlSessionFactory;    }}

测试类mai方法

package com.gxf.mybatis.util;import com.gxf.mybatis.mapper.PersonMapper;import com.gxf.mybatis.mapper.PersonMapper1;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;public class PersonTableOps {    private static SqlSessionFactory sqlSessionFactory = SqlSessionFactoryHelper.getSqlSessionFactory();    public static void main(String[] args) {//        selectOne1();//        selectOne2();        selectOne3();    }    /**     * 第一种方式     * */    public static void selectOne1(){        SqlSession session = sqlSessionFactory.openSession();        try {            Person person = session.selectOne(                    "com.gxf.mybatis.mapper.PersonMapper.selectPerson", 1);            System.out.println(person);        } finally {            session.close();        }    }    /**     * 第二种方式     * */    public static void selectOne2(){        SqlSession session = sqlSessionFactory.openSession();        try {            PersonMapper mapper = session.getMapper(PersonMapper.class);            Person person = mapper.selectPerson(1);            System.out.println(person);        } finally {            session.close();        }    }    /**     * 第三种方式     * */    public static void selectOne3(){        SqlSession session = sqlSessionFactory.openSession();        try {            sqlSessionFactory.getConfiguration().addMapper(PersonMapper1.class);            PersonMapper1 mapper = session.getMapper(PersonMapper1.class);            Person person = mapper.selectPerson(1);            System.out.println(person);        } finally {            session.close();        }    }}

转载于:https://www.cnblogs.com/luckygxf/p/9508995.html

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