04-Spring和MyBatis事务的处理

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/linzhaoliangyan/article/details/88740416

* 有问题可以参加Java技术交流群：839366464 

* 前期准备

        * Student，Teacher，Classes对象没有变

        * 在SM集成的基础上

   * dao

public interface ClassesMapper {
    /**
     * 查询教html班级的信息(包含老师)
     * @param cname
     * @return
     */

    public Classes queryClassesFromName(String cname);

    /**
     * cno : 班级号
     * isAdd:不是增加学生就是减少学生，true为增加学生，false为减少学生
     * @param map
     */
    public void updateClasses(HashMap map);
}

package com.hx.hx02.dao;

import com.hx.hx02.bean.Student;

import java.util.HashMap;
import java.util.List;

/**
 * @author xiaozhao
 */
public interface StudentMapper {
    /**
     * 查询某班级某学号学生信息
     * @param map
     * sid:学生姓名
     * cno:班级名称
     * @return map
     */
     Student queryStudent(HashMap map);

    /**
     * 更新学生的班级号
     * @param student
     */
     void updateStudent(Student student);
}


<?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.hx.hx02.dao.ClassesMapper">

	<select id="queryClassesFromName" parameterType="string" resultMap="rstc">
		SELECT * FROM classes c,teacher t,student s WHERE c.tid=t.tid AND c.cno=s.cno AND c.cname=#{c.cname}
	</select>

	<resultMap id="rstc" type="Classes">
		<id column="cno" property="cno"/>
		<result column="cname" property="cname"/>
		<result column="cnum" property="cnum"/>
		<result column="cdes" property="cdes"/>
		<association property="teacher" javaType="Teacher">
			<id column="tid" property="tid"/>
			<result column="tname" property="tname"/>
			<result column="tsex" property="tsex"/>
			<result column="tage" property="tage"/>
		</association>
		<collection property="students" ofType="Student">
			<id column="sid" property="sid"/>
			<result column="cno" property="cno"/>
			<result column="sname" property="sname"/>
			<result column="ssex" property="ssex"/>
			<result column="sage" property="sage"/>
			<result column="colleage" property="colleage"/>
		</collection>
	</resultMap>

	<!-- 方式一 -->
	<!--<select id="queryClassesFromName" parameterType="string" resultMap="rstc">
		SELECT * FROM classes c WHERE c.cname=#{cname}
	</select>

	<resultMap id="rstc" type="Classes">
		<id column="cno" property="cno"/>
		<result column="cname" property="cname"/>
		<result column="cnum" property="cnum"/>
		<result column="cdes" property="cdes"/>
		<association property="teacher" column="tid" select="getTeacher"></association>
	</resultMap>

	<select id="getTeacher" parameterType="int" resultType="Teacher">
		SELECT * FROM teacher t WHERE t.tid=#{tid}
	</select>-->


    <update id="updateClasses" parameterType="hashMap">
        UPDATE classes
          <set>
            <choose>
                <when test="isAdded==true">
                    cnum=cnum+1
                </when>
                <otherwise>
                    cnum=cnum-1
                </otherwise>
            </choose>
          </set>
          <where>
              <if test="cno!=null">
                  cno=#{cno}
              </if>
          </where>
    </update>
</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.hx.hx02.dao.StudentMapper">

    <select id="queryStudent" parameterType="Student" resultType="Student">
        SELECT sid,cno,sname,ssex,sage,colleage FROM student WHERE sid=#{sid} AND cno=#{cno}
    </select>

    <update id="updateStudent" parameterType="Student">
        UPDATE student SET cno=#{cno} WHERE sid=#{sid}
    </update>
</mapper>

* 业务层传递数据的实体

/**
 * @author xiaozhao
 */
public class TransferDataVo {
    private int sid;
    private int oldCno;
    private int newCno;

    public int getSid() {
        return sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    public int getOldCno() {
        return oldCno;
    }

    public void setOldCno(int oldCno) {
        this.oldCno = oldCno;
    }

    public int getNewCno() {
        return newCno;
    }

    public void setNewCno(int newCno) {
        this.newCno = newCno;
    }

    @Override
    public String toString() {
        return "TransferDataVo{" +
                "sid=" + sid +
                ", oldCno=" + oldCno +
                ", newCno=" + newCno +
                '}';
    }
}

* 业务层

public interface TransferService {
    /**
     *  某个学生转班
     * @param dataVo
     * @return
     */
    public boolean transfer(TransferDataVo dataVo);
}

package com.hx.hx02.service.impl;

import com.hx.hx02.bean.Student;
import com.hx.hx02.bean.vo.TransferDataVo;
import com.hx.hx02.dao.ClassesMapper;
import com.hx.hx02.dao.StudentMapper;
import com.hx.hx02.service.TransferService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.HashMap;

/**
 * @author xiaozhao
 */
@Service
public class TransferServiceImpl implements TransferService {
    @Autowired
    private ClassesMapper mClassesMapper;
    @Autowired
    private StudentMapper mStudentMapper;
    @Override
    public boolean transfer(TransferDataVo dataVo) {
        HashMap map=new HashMap();
        map.put("cno",dataVo.getOldCno());
        map.put("sid",dataVo.getSid());
        Student student = mStudentMapper.queryStudent(map);
        if(student!=null){
            // 设置学生为新班级
            student.setCno(dataVo.getNewCno());
            mStudentMapper.updateStudent(student);
            // 更新需要转班班级的人数
            map.put("cno",dataVo.getOldCno());
            map.put("isAdded",false);
            mClassesMapper.updateClasses(map);
            // 更新被转班班级的人数
            map.put("cno",dataVo.getNewCno());
            map.put("isAdded",true);
            mClassesMapper.updateClasses(map);
            return true;
        }else{
            System.out.println(dataVo.getOldCno()+"班级没有存在"+dataVo.getSid()+"学生");
        }
        return false;
    }
}

* 测试

  @Autowired
    private TransferService mTransferService;

    @Test
    public void test6(){
        TransferDataVo transferDataVo=new TransferDataVo();
        transferDataVo.setSid(100001);
        transferDataVo.setOldCno(1001);
        transferDataVo.setNewCno(1002);
        mTransferService.transfer(transferDataVo);
    }

 * 结果可以正确的更新数据

 * 模拟异常，继续测试

* 添加事务管理

      * 添加事务的命名工具

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/tx
	   http://www.springframework.org/schema/tx/spring-tx.xsd">

* 添加事务管理器    

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="c3p0"></property>
    </bean>

<tx:annotation-driven transaction-manager="transactionManager"/>

  * 配置

  @Transactional

* 测试ok

* 有问题可以参加Java技术交流群：839366464