Mybatis系列之全注解方式操作数据库例子

我不是女神ヾ 2021-09-10 23:36 317阅读 0赞

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User.java:

package com.mybatis.entity;
    
    public class User {
    
    	/*
    	 * ID
    	 */
    	private int id;
    	
    	/*
    	 * 用户姓名 
    	 */
    	private String name;
    	
    	/*
    	 * age
    	 */
    	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 "User [id=" + id + ", name=" + name + ", age=" + age + "]";
    	}
    	
    }

注解方式的UserMapper.java

package com.mybatis.mapper;
    
    import java.util.List;
    
    import org.apache.ibatis.annotations.Delete;
    import org.apache.ibatis.annotations.Insert;
    import org.apache.ibatis.annotations.Select;
    import org.apache.ibatis.annotations.Update;
    
    import com.mybatis.entity.User;
    
    public interface UserMapper {
    	@Insert("insert into users(name,age) values(#{name},#{age})")
    	public void save(User user);
    	@Update("update users set name=#{name},age=#{age} where id=#{id}")
    	public boolean update(User user);
    	@Delete("delete from users where id=#{id}")
    	public boolean delete(int id);
    	@Select("select * from users where id=#{id}")
    	public User findById(int id);
    	@Select("select * from users")
    	public List<User> findAll();
    }

注册这个接口,mybatis-config.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>
    	
    	 
        <properties resource="db.properties" />  
         
       
    	<typeAliases>
    		<typeAlias alias="User" type="com.mybatis.entity.User" />
    	</typeAliases>
    	
    	
    	<environments default="development">
    		<environment id="development">
    			<transactionManager type="JDBC" />
    			<dataSource type="POOLED">
    				<property name="driver" value="${driver}"/>
    	            <property name="url" value="${url}" />
    	            <property name="username" value="${username}"/>
    	            <property name="password" value="${password}"/>
    			</dataSource>
    		</environment>
    	</environments>
    	
    	
    	
    	<mappers>
    		<mapper class="com.mybatis.mapper.UserMapper"/>
    	</mappers>
    	
    </configuration>

db.properties:

driver=com.mysql.jdbc.Driver
    url=jdbc\:mysql\://localhost\:3306/db_mysql?useUnicode\=true&characterEncoding\=utf-8
    username=root
    password=111

日志文件

log4j.properties\uFF0C
    log4j.rootLogger=DEBUG, Console
    #Console
    log4j.appender.Console=org.apache.log4j.ConsoleAppender
    log4j.appender.Console.layout=org.apache.log4j.PatternLayout
    log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n
    log4j.logger.java.sql.ResultSet=INFO
    log4j.logger.org.apache=INFO
    log4j.logger.java.sql.Connection=DEBUG
    log4j.logger.java.sql.Statement=DEBUG
    log4j.logger.java.sql.PreparedStatement=DEBUG

进行测试：

import java.io.Reader;
    
    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 com.mybatis.entity.User;
    import com.mybatis.mapper.UserMapper;
    
    
    public class Test {
    
    	public static void main(String[] args) {
    //		String resource = "mybatis-config.xml";
    //		try{
    //			//加载Mybatis的配置文件
    //			Reader reader = Resources.getResourceAsReader(resource);
    //			//构建sqlSession的工厂
    //	        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
    //			//创建可以执行sql的SqlSession
    //	        SqlSession session = sessionFactory.openSession();
    //			//映射sql的标志字符串
    //	        String statement = "com.mybatis.mapper.userMapper.findById";
    //	        //执行查询返回id为1的User对象
    //			User user = session.selectOne(statement,1);
    //			System.out.println(user);
    //			
    //		}catch (Exception e) {
    //			e.printStackTrace();
    //		}
    		
    		String resource = "mybatis-config.xml";
    		try{
    			//加载Mybatis的配置文件
    			Reader reader = Resources.getResourceAsReader(resource);
    			//构建sqlSession的工厂
    	        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
    			//创建可以执行sql的SqlSession
    	        SqlSession session = sessionFactory.openSession();
    			UserMapper mapper = session.getMapper(UserMapper.class);
    			User user = mapper.findById(1);
    	        System.out.println(user);
    		}catch (Exception e) {
    			e.printStackTrace();
    		}
    		
    		
    	}
    }

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