Mybatis接口编程方式实现增删改查

桃扇骨 2021-09-10 12:46 276阅读 0赞

[林炳文Evankaka][Evankaka]原创作品。转载请注明出处[http://blog.csdn.net/evankaka][http_blog.csdn.net_evankaka]

前面一章[【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ][Mybatis_Mybatis_Mybatis_]，已经搭建好了eclipse,mybatis,mysql的环境，并且实现了一个简单的查询。请注意，这种方式是用SqlSession实例来直接执行已映射的SQL语句：

session.selectOne("com.mucfc.model.EmployeerMapper.findEmployeerByID", 1);

其实还有更简单的方法，而且是更好的方法，使用合理描述参数和SQL语句返回值的接口（比如EmployeerMapper.java），这样现在就可以至此那个更简单，更安全的代码，没有容易发生的字符串文字和转换的错误.下面是详细过程:

本文要改成以接口类来实现增删改查

整个工程目录 ：

![20150513091906306][]

[本文示例工程免费下载][Link 1]

1、首先还是mybatis的配置文件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="mysql.properties" /> 
    	
    	<typeAliases>
    		<typeAlias alias="Employeer" type="com.mucfc.model.Employeer"  />
    	</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 resource="com/mucfc/model/Employeer.xml" />
    	</mappers>
    </configuration>

其中配置文件mysql.properties

driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://localhost:3306/test?charset=utf8
    username=root
    password=christmas258@

2、数据表对应的类Employeer.JAVA

package com.mucfc.model;
    
    import java.io.Serializable;
    
    /**
     * 雇员信息类
     *@author linbingwen
     *@time 2015.5.11
     */
    public class Employeer {
    	private Integer employeer_id;
    	private String employeer_name;
    	private Integer employeer_age ;
    	private String employeer_department;
    	private String employeer_worktype;
    	
    	public Employeer() {
    		super();
    	}
    	public Integer getEmployeer_id() {
    		return employeer_id;
    	}
    	public void setEmployeer_id(Integer employeer_id) {
    		this.employeer_id = employeer_id;
    	}
    	public String getEmployeer_name() {
    		return employeer_name;
    	}
    	public void setEmployeer_name(String employeer_name) {
    		this.employeer_name = employeer_name;
    	}
    	public Integer getEmployeer_age() {
    		return employeer_age;
    	}
    	public void setEmployeer_age(Integer employeer_age) {
    		this.employeer_age = employeer_age;
    	}
    	public String getEmployeer_department() {
    		return employeer_department;
    	}
    	public void setEmployeer_department(String employeer_department) {
    		this.employeer_department = employeer_department;
    	}
    	public String getEmployeer_worktype() {
    		return employeer_worktype;
    	}
    	public void setEmployeer_worktype(String employeer_worktype) {
    		this.employeer_worktype = employeer_worktype;
    	}
    	@Override
    	public String toString() {
    		return "Employeer [employeer_id=" + employeer_id + ", employeer_name="
    				+ employeer_name + ", employeer_age=" + employeer_age
    				+ ", employeer_department=" + employeer_department
    				+ ", employeer_worktype=" + employeer_worktype + "]";
    	}
    	
    
    
    }

然后是SQL语句的配置Employeer.xml：

<?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.mucfc.mapper.EmployeerMapper">
     
         
         <select id="findEmployeerByID" parameterType="int" resultType="Employeer">
         select* from `t_employeer` where employeer_id =#{employeer_id}
         </select>
         
            
           
        <insert id="addEmployeer" parameterType="Employeer"
        useGeneratedKeys="true" keyProperty="employeer_id">  
            insert into `t_employeer`(employeer_name,employeer_age,employeer_department,employeer_worktype) 
            values(#{employeer_name},#{employeer_age},#{employeer_department},#{employeer_worktype})  
        </insert>  
        
         
        <delete id="deleteEmployeer" parameterType="int">  
            delete from `t_employeer` where employeer_id = #{employeer_id}  
        </delete>  
        
          
        <update id="updateEmployeer" parameterType="Employeer">  
            update t_employeer set employeer_name = #{employeer_name},employeer_age= #{employeer_age},employeer_department = #{employeer_department}
            ,employeer_worktype=#{employeer_worktype}  where employeer_id = #{employeer_id}  
        </update>  
        
     </mapper>

注意com.mucfc.mapper.EmployeerMapper这个类是存在的，它是一个接口类，上一讲我们是使用 com.mucfc.model.EmployeerMapper，而上一讲的这个类是不存在的

4、SQL语句映射类EmployeerMapper.java

package com.mucfc.mapper;
    
    import com.mucfc.model.Employeer;
    
    /**
     * SQL语句映射类
     * @author linbingwen
     * @time 2015.5.11
     */
    public interface EmployeerMapper {
    	/**
    	 * 注意要和Employeer.xml的方法名对应
    	 */
    	public Employeer findEmployeerByID(int id);
    
    	/**
    	 * 注意要和Employeer.xml的方法名对应
    	 */
    	public void addEmployeer(Employeer employeer);
    
    	/**
    	 * 注意要和Employeer.xml的方法名对应
    	 */
    	public void deleteEmployeer(int id);
    
    	/**
    	 * 注意要和Employeer.xml的方法名对应
    	 */
    	public void updateEmployeer(Employeer employeer);
    
    }

5、测试：

（1）增加命令

上一讲[【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ][Mybatis_Mybatis_Mybatis_]中的方式：

/**
    	 * 增加
    	 */
    	public static void addEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			 //返回值是记录条数  
                int resultCount = session.insert("com.mucfc.model.EmployeerMapper.addEmployeer", employeer );  
                System.out.printf("当前插入的employeer_id :%d    当前插入数据库中条数:%d " , employeer.getEmployeer_id() ,resultCount);  //获取插入对象的id  
                System.out.println("");
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}

改成以接口编程的方式：

/**
    	 * 增加
    	 */
    	public static void addEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.addEmployeer(employeer);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}

（2）删除命令

上一讲[【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ][Mybatis_Mybatis_Mybatis_]中的方式：

/**
    	 * 删除
    	 * 
    	 */
    	public static void deleteEmployeer(int id){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			 //返回值是记录条数  
    			 int resultCount=session.delete("com.mucfc.model.EmployeerMapper.deleteEmployeer",id); 
    			  System.out.println("当前删除数据库中条数: "+resultCount);  //获取插入对象的id  
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    	}

改成以接口编程的方式：

/**
    	 * 删除
    	 * 
    	 */
    	public static void deleteEmployeer(int id){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.deleteEmployeer(id);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    	}

（3）查找命令

上一讲[【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ][Mybatis_Mybatis_Mybatis_]中的方式：

/**
    	 * 查找
    	 */
    	public static void findEmployeerById(int id) {
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			Employeer employeer = (Employeer) session.selectOne(
    					"com.mucfc.model.EmployeerMapper.findEmployeerByID", 1);
    			if (employeer == null)
    				System.out.println("null");
    			else
    				System.out.println(employeer);
    		} finally {
    			session.close();
    		}
    	}

改成以接口编程的方式：

/**
    	 * 查找
    	 */
    	public static void findEmployeerById(int id) {
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			Employeer employeer=employeerMapper.findEmployeerByID(id);
    			if (employeer == null)
    				System.out.println("null");
    			else
    				System.out.println(employeer);
    		} finally {
    			session.close();
    		}
    	}

（4）修改命令

上一讲[【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ][Mybatis_Mybatis_Mybatis_]中的方式：

/**
    	 * 更改
    	 */
    	public static void updateEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession(); 
                session.update("com.mucfc.model.EmployeerMapper.updateEmployeer",employeer);    
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}

改成以接口编程的方式：

/**
    	 * 更改
    	 */
    	public static void updateEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession(); 
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.updateEmployeer(employeer);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}

这是一个完整的测试：

package com.mucfc.test;
    
    import java.io.IOException;
    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.mucfc.mapper.EmployeerMapper;
    import com.mucfc.model.Employeer;
    
    public class MybatisTest {
    	private static SqlSessionFactory sqlSessionFactory;
    	private static Reader reader;
    	static {
    		try {
    			reader = Resources.getResourceAsReader("mybatis-config.xml");
    			sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 查找
    	 */
    	public static void findEmployeerById(int id) {
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			Employeer employeer=employeerMapper.findEmployeerByID(id);
    			if (employeer == null)
    				System.out.println("null");
    			else
    				System.out.println(employeer);
    		} finally {
    			session.close();
    		}
    	}
    	/**
    	 * 增加
    	 */
    	public static void addEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.addEmployeer(employeer);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}
    	/**
    	 * 删除
    	 * 
    	 */
    	public static void deleteEmployeer(int id){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession();
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.deleteEmployeer(id);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    	}
    	/**
    	 * 更改
    	 */
    	public static void updateEmployeer(Employeer employeer){
    		SqlSession session = null;
    		try {
    			session = sqlSessionFactory.openSession(); 
    			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
    			employeerMapper.updateEmployeer(employeer);
                session.commit() ;  		
    		} finally {
    			session.close();
    		}
    		
    	}
    
    	public static void main(String[] args) {							
    		Employeer employeer1=new Employeer();
    		employeer1.setEmployeer_name("李四");
    		employeer1.setEmployeer_age(23);
    		employeer1.setEmployeer_department("产品一部");
    		employeer1.setEmployeer_worktype("开发工程师");
    		
    		Employeer employeer2=new Employeer();
    		employeer2.setEmployeer_name("张三");
    		employeer2.setEmployeer_age(30);
    		employeer2.setEmployeer_department("产品二部");
    		employeer2.setEmployeer_worktype("测试工程师");
    		
    		Employeer employeer3=new Employeer();
    		employeer3.setEmployeer_name("小王");
    		employeer3.setEmployeer_age(22);
    		employeer3.setEmployeer_department("产品三部");
    		employeer3.setEmployeer_worktype("数据分析师");
    		
    		
    		Employeer employeer4=new Employeer();
    		employeer4.setEmployeer_name("明明");
    		employeer4.setEmployeer_age(22);
    		employeer4.setEmployeer_department("财会部");
    		employeer4.setEmployeer_worktype("财务人员");
    	
    		//插入
         	addEmployeer(employeer1);
         	addEmployeer(employeer2);
         	addEmployeer(employeer3);
         	addEmployeer(employeer4);
         	findEmployeerById(26);
         	deleteEmployeer(27);
    		
    		//更改
    		employeer2.setEmployeer_id(28);
    		employeer2.setEmployeer_age(21);
    		employeer2.setEmployeer_department("产品四部");
    		updateEmployeer(employeer2);
    
    	}
    
    }

测试结果：

插入了4条数据，ID为25~28

然后27号被删除

29号被修改

![20150512160517539][][  
][Link 1]

[本文示例工程免费下载][Link 1]

[林炳文Evankaka][Evankaka]原创作品。转载请注明出处[http://blog.csdn.net/evankaka][http_blog.csdn.net_evankaka]

[Evankaka]: http://my.csdn.net/Evankaka
[http_blog.csdn.net_evankaka]: http://blog.csdn.net/evankaka
[Mybatis_Mybatis_Mybatis_]: http://blog.csdn.net/evankaka/article/details/45647401
[20150513091906306]: /images/20210811/c1928ba4573a4008a84b5aa1c7feab39.png
[Link 1]: http://download.csdn.net/detail/evankaka/8693771
[20150512160517539]: /images/20210811/b36a72c4c5c64009b1f4536ca8450903.png