mybatis整合Mapper通用工具，实现单表基本操作

木秀于林，风必摧之

文档资料：https://github.com/abel533/Mapper

需要导入的maven依赖文件如下：

<dependency>
			<groupId>tk.mybatis</groupId>
			<artifactId>mapper</artifactId>
			<version>3.2.2</version>
		</dependency>
		
		<dependency>
			<groupId>javax.persistence</groupId>
			<artifactId>persistence-api</artifactId>
			<version>1.0</version>
		</dependency>

* 第二个是用于model注解的使用。

mybatis.xml配置文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
		                    http://www.springframework.org/schema/beans/spring-beans.xsd 		                    http://www.springframework.org/schema/context 
		                    http://www.springframework.org/schema/context/spring-context.xsd 		                    http://www.springframework.org/schema/tx 
		                    http://www.springframework.org/schema/tx/spring-tx.xsd 		                    http://www.springframework.org/schema/aop 
		                    http://www.springframework.org/schema/aop/spring-aop.xsd"> 	<!-- 配置MyBatis SqlSessionFactory -->
	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<property name="dataSource" ref="dataSource" />
		<property name="configLocation" value="classpath:myBatis-config.xml"></property>
		<property name="mapperLocations"
			value="classpath*:com/citic/gatz/mapping/*Mapper.xml"></property>
	</bean>
	<!-- 采用自动扫描包的形式来实例化dao层 -->
	<bean class="tk.mybatis.spring.mapper.MapperScannerConfigurer">
		<property name="basePackage" value="com.citic.gatz.dao.**" />
		<property name="properties">
			<value>
				mappers=tk.mybatis.mapper.common.Mapper
			</value>
		</property>
	</bean>
</beans>

mybatis-config.xml文件如下：

<?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>
	<settings>
		<setting name="cacheEnabled" value="false" />
		<setting name="useGeneratedKeys" value="true" />
		<setting name="defaultExecutorType" value="REUSE" />
	</settings>
	<!-- 别名配置 -->
	<typeAliases>
		<package name="com.citic.gatz.model" />
	</typeAliases>
	
	<plugins>
		<plugin interceptor="com.github.pagehelper.PageHelper">
			<property name="dialect" value="mysql" />
		</plugin>
	</plugins>
</configuration>

IBaseDao:

package com.citic.gatz.base;

import tk.mybatis.mapper.common.BaseMapper;

/**
 * 
 * @author fengchao
 * Mapper中通用的方法：
 * 		继承了base组合接口中的4个组合接口，包含完整的CRUD方法
 *
 * @param <T>
 */
public interface IBaseMapper<T> extends BaseMapper<T> {

}

以UserTest为例来说明：

sql：

CREATE TABLE `user_test` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(32) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=78 DEFAULT CHARSET=utf8;

model：

package com.citic.gatz.model;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Table;
/**
 * model层测试类
 * @author fengchao
 *
 */
@Table(name="user_test")
public class UserTest implements Serializable {
	private static final long serialVersionUID = 6626527450093471276L;
	@Id  
    @Column(name = "id") 
	private Integer id;
	
	private String username;
	
	private Integer age;

	public Integer getId() {
		return id;
	}

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

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}
}

*若有的属性不需要和数据库挂钩，在使用@Transient进行注解标示

dao：

package com.citic.gatz.dao;

import java.util.List;

import com.citic.gatz.base.IBaseMapper;
import com.citic.gatz.model.UserTest;

public interface UserTestMapper extends IBaseMapper<UserTest> {
	/**
	 * 根据username查找对应的信息
	 * @param username
	 * @return
	 */
	List<UserTest> selectByUsername(String username);
}

*其中里面有一个特点的业务的方法selectByUsername,只时候需要自己在Mapper文件里面完善。

mapper：

<?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.citic.gatz.dao.UserTestMapper">
	<resultMap id="BaseResultMap" type="userTest">
		<id column="id" property="id" jdbcType="INTEGER" />
		<result column="username" property="username" jdbcType="VARCHAR" />
		<result column="age" property="age" jdbcType="INTEGER" />
	</resultMap>
  
  	<sql id="Base_Column_List" >
        id,username,age
  	</sql>
	
	<!-- 根据用户名查找 -->
	<select id="selectByUsername" parameterType="java.lang.String" resultMap="BaseResultMap">
		select
			<include refid="Base_Column_List" />
		from
			user_test ut
		where 
			ut.username = #{username}
	</select>
</mapper>

测试类如下：

package com.dao.test;

import java.util.List;

import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.citic.gatz.dao.UserTestMapper;
import com.citic.gatz.model.UserTest;
import com.github.pagehelper.PageHelper;

@RunWith(SpringJUnit4ClassRunner.class)  
@ContextConfiguration(locations ={"classpath:beans.xml"})
public class UserTestDaoTest {
	@Autowired
	private UserTestMapper userTestMapper;
	
	@Test
	public void insert() {
		for(int i = 0; i < 10; i++) {
			UserTest obj = new UserTest();
			obj.setUsername("feng" + i);
			obj.setAge(24 + i);
			int insert = userTestMapper.insert(obj);
			System.out.println(insert);
		}
	}
	
	@Test
	public void delete() {
		int key = userTestMapper.deleteByPrimaryKey(8);
		System.out.println(key);
	}
	
	@Test
	public void update() {
		UserTest userTest = userTestMapper.selectByPrimaryKey(7);
		userTest.setUsername("saaa");
		
		//根据主键更新实体全部字段，null值会被更新
		int key = userTestMapper.updateByPrimaryKey(userTest);
		System.out.println(key);
	}
	
	@Test
	public void find() {
		PageHelper.startPage(2, 3);  //第二页 三条数据
		List<UserTest> list = userTestMapper.selectAll();
		for (UserTest userTest : list) {
			System.out.println(userTest.getUsername());
		}
	}
	
	@Test
	public void findByUsername() {
		List<UserTest> list = userTestMapper.selectByUsername("feng9");
		for (UserTest userTest : list) {
			System.out.println(userTest.getUsername());
		}
	}
}

除了最后一个方法是自己写的，其余的都是通过Mapper插件完成。 完毕！详细API还是查找文档······