spring3+mbatis3开发实例

• 2020 年 1 月 7 日
• 筆記

最近一直在深入了解struts2，spring，hibernate以及mybatis框架，通过查看这些框架的源码和官方文档，发现自己对于这些框架的原理，使用有了更深的理解，那么今天

我给大家带来的是运用spring和mybatis这两个框架来开发的小例子，并给大家讲述一些开发中需要注意的一些细节。

1、新建一个web项目，修改web.xml文件，我的文件内容如下，大家把需要的拷走就行：

<?xml version="1.0" encoding="UTF-8"?>  <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns="http://java.sun.com/xml/ns/javaee"  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"  id="WebApp_ID" version="2.5">  <display-name>dreamMall-dubbo-provider</display-name>  <!-- 加载spring文件监听器 -->  <listener>  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>  </listener>  <!-- 加载log4j监听器 -->  <listener>  <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>  </listener>  <!-- 解决spring容器运行时可能产生的内存溢出 -->  <listener>  <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>  </listener>  <!-- spring文件路径 -->  <context-param>  <param-name>contextConfigLocation</param-name>  <param-value>classpath:spring-*.xml</param-value>  </context-param>  <!-- log4j文件路径 -->  <context-param>  <param-name>log4jConfigLocation</param-name>  <param-value>classpath:log4j.properties</param-value>  </context-param>  <!-- 开启watchdog线程监测配置文件的变化 -->  <context-param>  <param-name>log4jRefreshInterval</param-name>  <param-value>60000</param-value>  </context-param>  <!-- 设置编码格式 -->  <filter>  <filter-name>CharacterEncoding</filter-name>  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  <init-param>  <param-name>encoding</param-name>  <param-value>UTF-8</param-value>  </init-param>  <init-param>  <param-name>forceEncoding</param-name>  <param-value>true</param-value>  </init-param>  </filter>  <filter-mapping>  <filter-name>CharacterEncoding</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>  <!-- 配置session超时时间 -->  <session-config>           <session-timeout>30</session-timeout>      </session-config>  </web-app>

2、新建spring-app.xml和spring-mybatis.xml文件,其中：

spring-app.xml:

<?xml version="1.0" encoding="UTF-8"?>    <beans xmlns="http://www.springframework.org/schema/beans"   xmlns:aop="http://www.springframework.org/schema/aop"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns:p="http://www.springframework.org/schema/p"  xmlns:tx="http://www.springframework.org/schema/tx"   xmlns:context="http://www.springframework.org/schema/context"   xmlns:mvc="http://www.springframework.org/schema/mvc"   xsi:schemaLocation="        http://www.springframework.org/schema/beans         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd      http://www.springframework.org/schema/aop           http://www.springframework.org/schema/aop/spring-aop-3.0.xsd        http://www.springframework.org/schema/context        http://www.springframework.org/schema/context/spring-context-3.0.xsd      http://www.springframework.org/schema/tx        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd         http://www.springframework.org/schema/mvc        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"  default-autowire="byName">     <context:component-scan base-package="com.mall.dubbo" />      <aop:aspectj-autoproxy />  </beans>

注释的方法大家不用管，这些是我在下一篇博客要给大家带来的关于spring中aop的技术以及使用aop实现事务的管理

spring-mybatis.xml:

<?xml version="1.0" encoding="UTF-8"?>  <beans xmlns="http://www.springframework.org/schema/beans"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"  xmlns:context="http://www.springframework.org/schema/context"  xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"  xsi:schemaLocation="        http://www.springframework.org/schema/beans         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd        http://www.springframework.org/schema/context        http://www.springframework.org/schema/context/spring-context-3.0.xsd        http://www.springframework.org/schema/mvc        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd      http://www.springframework.org/schema/tx      http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"  default-autowire="byName">  <bean id="dbConfig"  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">  <property name="location">  <value>classpath:jdbc.properties</value>  </property>  </bean>  <!-- <context:property-placeholder location="classpath:jdbc.properties" /> -->  <!-- 配置数据源 -->  <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">  <property name="driverClassName" value="com.mysql.jdbc.Driver"/>  <property name="url" value="jdbc:mysql://localhost:3306/dreammall?useUnicode=true&characterEncoding=utf-8" />  <property name="username" value="root" />  <property name="password" value="1" />  </bean>  <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  <property name="mapperLocations" value="classpath:com/mall/dubbo/map/*.xml" />  <property name="dataSource" ref="dataSource" />  </bean>  <!-- 注册Mapper方式二：也可不指定特定mapper，而使用自动扫描包的方式来注册各种Mapper ，配置如下： -->  <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  <property name="basePackage" value="com.mall.dubbo.dao" />  <property name="markerInterface" value="com.mall.dubbo.dao.GenericDao" />  <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />   </bean>  </beans>

这里大家需要关注的是Mapper的注册方式，这里我采用的所有的dao都继承GenericiDao，这样的话,你就不需要再去一个一个Mapper的注册，开发中经常使用的是这种方式。

3、这里我需要简单的表述一下我的数据库中表的对于关系，我用了测试的有三个表，teacher表，cource表，student表，我假定一个teacher教一门Cource，一个teacher交

n个student，下面我用3个实体类来描述着三者的关系：

cource.java:

package com.mall.dubbo.entity;  import java.io.Serializable;  public class Cource implements Serializable {  /**   *    */  private static final long serialVersionUID = 1L;  private int id;  private String courceName;  private int teacherId;  public int getId() {  return id;  }  public void setId(int id) {  this.id = id;  }  public int getTeacherId() {  return teacherId;  }  public void setTeacherId(int teacherId) {  this.teacherId = teacherId;  }  public String getCourceName() {  return courceName;  }  public void setCourceName(String courceName) {  this.courceName = courceName;  }  @Override  public String toString() {  return "Cource [id=" + id + ", courceName=" + courceName + "]";  }  }

student.java:

package com.mall.dubbo.entity;  import java.io.Serializable;  public class Student implements Serializable {  /**   *    */  private static final long serialVersionUID = 1L;  private int id;  private int age;  private String studentName;  private int sex;  private int teacherId;  public int getId() {  return id;  }  public void setId(int id) {  this.id = id;  }  public int getAge() {  return age;  }  public void setAge(int age) {  this.age = age;  }  public String getStudentName() {  return studentName;  }  public void setStudentName(String studentName) {  this.studentName = studentName;  }  public int getSex() {  return sex;  }  public void setSex(int sex) {  this.sex = sex;  }  public int getTeacherId() {  return teacherId;  }  public void setTeacherId(int teacherId) {  this.teacherId = teacherId;  }  @Override  public String toString() {  return "Student [id=" + id + ", age=" + age + ", studentName="  + studentName + ", sex=" + sex + "]";  }  }

Teacher.java:

package com.mall.dubbo.entity;  import java.io.Serializable;  import java.util.List;  public class Teacher implements Serializable{  /**   *    */  private static final long serialVersionUID = 1L;  private int id;  private String teacherName;  private int sex;  private int age;  private Cource cource;  private List<Student> students;  public int getId() {  return id;  }  public void setId(int id) {  this.id = id;  }  public String getTeacherName() {  return teacherName;  }  public void setTeacherName(String teacherName) {  this.teacherName = teacherName;  }  public int getSex() {  return sex;  }  public void setSex(int sex) {  this.sex = sex;  }  public int getAge() {  return age;  }  public void setAge(int age) {  this.age = age;  }  public Cource getCource() {  return cource;  }  public void setCource(Cource cource) {  this.cource = cource;  }  public List<Student> getStudents() {  return students;  }  public void setStudents(List<Student> students) {  this.students = students;  }  @Override  public String toString() {  return "Teacher [id=" + id + ", teacherName=" + teacherName + ", sex="  + sex + ", age=" + age + "]";  }  }

4、建立映射关系，这部分是最重要的，这里面的知识点，我希望大家可以好好看，如果有什么问题的，可以评论留言，或者去查看mybatis3.2的官方文档

地址是 http://wenku.baidu.com/link?url=L6Lu0GufwrMCgBLGUbsfGy7Os6s7MEcKIsZQj7JhOxIo6BSbsULynqsWeqX0mIyIqkzLIozaQvnaAUROrWypUDQj3QBfe5j6jO3solfO3-G

cource.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.mall.dubbo.dao.CourceDao">  <resultMap type="com.mall.dubbo.entity.Cource" id="courceMap">  <id property="id" column="id" javaType="int" jdbcType="INTEGER"/>  <result property="courceName" column="cource_name" javaType="String" jdbcType="VARCHAR"/>  <result property="teacherId" column="teacher_id" javaType="int" jdbcType="INTEGER"/>  </resultMap>  <parameterMap type="com.mall.dubbo.entity.Cource" id="paraMap">  <parameter property="id"/>  <parameter property="courceName"/>  <parameter property="teacherId"/>  </parameterMap>  <sql id="courceSql">id,cource_name,teacher_id</sql>  <select id="selectAll" resultMap="courceMap">  select <include refid="courceSql"/> from cource  </select>  <select id="selectById" parameterType="int" resultMap="courceMap">  select <include refid="courceSql"/> from cource where  id=#{id,javaType=int,jdbcType=INTEGER}  </select>  <insert id="addCource" parameterMap="paraMap">  insert into cource (<include refid="courceSql"/>) values(  #{id,javaType=int,jdbcType=INTEGER},  #{courceName,javaType=String,jdbcType=VARCHAR},  #{teacherId,javaType=int,jdbcType=INTEGER}  )  </insert>  <update id="updateCourceById" parameterType="com.mall.dubbo.entity.Cource">  update cource set  cource_name=#{courceName,javaType=String,jdbcType=VARCHAR},  teacher_id=#{teacherId,javaType=int,jdbcType=INTEGER}  where id=#{id,javaType=int,jdbcType=INTEGER}  </update>  <delete id="deleteCourceById" parameterType="int">  delete from cource where id=#{id,javaType=int,jdbcType=INTEGER}  </delete>  <delete id="deleteAll">  delete from cource  </delete>  </mapper>

student.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.mall.dubbo.dao.StudentDao">  <resultMap type="com.mall.dubbo.entity.Student" id="studentMap">  <id property="id" column="id" javaType="int" jdbcType="INTEGER"/>  <result property="age" column="age" javaType="int" jdbcType="INTEGER"/>  <result property="studentName" column="student_name" javaType="String" jdbcType="VARCHAR"/>  <result property="sex" column="sex" javaType="int" jdbcType="INTEGER"/>  <result property="teacherId" column="teacher_id" javaType="int" jdbcType="INTEGER"/>  </resultMap>  <parameterMap type="com.mall.dubbo.entity.Student" id="parameMap">  <parameter property="id"/>  <parameter property="age"/>  <parameter property="studentName"/>  <parameter property="sex"/>  <parameter property="teacherId"/>  </parameterMap>  <sql id="studentSql">id,age,student_name,sex,teacher_id</sql>  <select id="selectAll" resultMap="studentMap">  select <include refid="studentSql"/> from student  </select>  <select id="selectById" parameterType="int" resultMap="studentMap">  select <include refid="studentSql"/> from student where id=#{id,javaType=int,jdbcType=INTEGER}  </select>  <insert id="addStudent" parameterType="com.mall.dubbo.entity.Student">  insert into student(<include refid="studentSql"/>) values (  #{id,javaType=int,jdbcType=INTEGER},  #{age,javaType=int,jdbcType=INTEGER},  #{studentName,javaType=String,jdbcType=VARCHAR},  #{sex,javaType=int,jdbcType=INTEGER},  #{teacherId,javaType=int,jdbcType=INTEGER}  )  </insert>  <update id="updateStudentById" parameterMap="parameMap">  update student set  age=#{age,javaType=int,jdbcType=INTEGER},  student_name=#{studentName,javaType=String,jdbcType=VARCHAR},  sex=#{sex,javaType=int,jdbcType=INTEGER},  teacher_id=#{teacherId,javaType=int,jdbcType=INTEGER}  where id=#{id,javaType=int,jdbcType=INTEGER}  </update>  <delete id="deleteStudentById" parameterType="int">  delete from student where id=#{id,javaType=int,jdbcType=INTEGER}  </delete>  <delete id="deleteAll">  delete from student  </delete>  </mapper>

teacher.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.mall.dubbo.dao.TeacherDao">  <resultMap type="com.mall.dubbo.entity.Teacher" id="TeacherMap">  <id property="id" column="id" javaType="int" jdbcType="INTEGER" />  <result property="teacherName" column="teacher_name" javaType="String"  jdbcType="VARCHAR" />  <result property="age" column="age" javaType="int" jdbcType="INTEGER" />  <result property="sex" column="sex" javaType="int" jdbcType="INTEGER" />  <!-- 方法一 -->  <!-- 使用这种方式，coulumn的名字不能重复，否则识别不了 -->  <association property="cource" javaType="com.mall.dubbo.entity.Cource">  <id property="id" column="cource_id" javaType="int" jdbcType="INTEGER" />  <result property="courceName" column="cource_name" javaType="String"  jdbcType="VARCHAR" />  <result property="teacherId" column="c_teacher_id" javaType="int"  jdbcType="INTEGER" />  </association>  <!-- 方法二 -->  <!-- <association property="cource" javaType="com.mall.dubbo.entity.Cource"   resultMap="courceMap"/> -->  <!-- 方法三 -->  <association property="cource" javaType="com.mall.dubbo.entity.Cource"   column="teacher_id" select="selectCourceById"/>  <!-- 方法一 -->  <!-- 使用这种方式，coulumn的名字不能重复，否则识别不了 -->  <collection property="students" ofType="com.mall.dubbo.entity.Student">  <id property="id" column="student_id" javaType="int" jdbcType="INTEGER" />  <result property="age" column="s_age" javaType="int" jdbcType="INTEGER" />  <result property="studentName" column="student_name" javaType="String"  jdbcType="VARCHAR" />  <result property="sex" column="s_sex" javaType="int" jdbcType="INTEGER" />  <result property="teacherId" column="s_teacher_id" javaType="int"  jdbcType="INTEGER" />  </collection>  <!-- 方法二 -->  <!-- <collection property="students" ofType="com.mall.dubbo.entity.Student"   resultMap="studentMap"/> -->  <!-- 方法三 -->  <!-- <collection property="students" ofType="com.mall.dubbo.entity.Student"   column="teacher_id" select="selectStudentByTeacherId"/> -->  </resultMap>  <!-- 对应于方法二 -->  <!-- <resultMap type="com.mall.dubbo.entity.Cource" id="courceMap"> <id   property="id" column="cource_id" javaType="int" jdbcType="INTEGER"/>   <result property="courceName" column="cource_name" javaType="String" jdbcType="VARCHAR"/>   <result property="teacherId"  column="c_teacher_id" javaType="int" jdbcType="INTEGER"/>   </resultMap> -->  <!-- 对应于方法二 -->  <!-- <resultMap type="com.mall.dubbo.entity.Student" id="studentMap"> <id   property="id" column="student_id" javaType="int" jdbcType="INTEGER"/>   <result property="age" column="s_age" javaType="int" jdbcType="INTEGER"/>  <result property="studentName" column="student_name" javaType="String" jdbcType="VARCHAR"/>   <result property="sex" column="s_sex" javaType="int" jdbcType="INTEGER"/>  <result property="teacherId" column="s_teacher_id" javaType="int" jdbcType="INTEGER"/>   </resultMap> -->  <parameterMap type="com.mall.dubbo.entity.Teacher" id="paraMap">  <parameter property="id" />  <parameter property="teacherName" />  <parameter property="age" />  <parameter property="sex" />  </parameterMap>  <sql id="teacherSql">id,teacher_name,age,sex</sql>  <!-- 对应于方法三 -->  <!-- <select id="selectCourceByTeacherId" parameterType="int" resultType="com.mall.dubbo.entity.Cource">   select * from cource where teacher_id=#{id,javaType=int,jdbcType=INTEGER}   </select>  <select id="selectStudentByTeacherId" parameterType="int" resultType="com.mall.dubbo.entity.Student">   select * from student where teacher_id=#{id,javaType=int,jdbcType=INTEGER}   </select> -->  <select id="selectTeacerById" parameterType="int" resultMap="TeacherMap">  select t.*,s.id student_id,s.age s_age,s.sex s_sex,s.teacher_id s_teacher_id,s.student_name,  c.id cource_id,c.cource_name,c.teacher_id c_teacher_id  from teacher t join cource c on t.id=c.teacher_id left outer join student  s on t.id=s.teacher_id  where t.id=#{id,javaType=int,jdbcType=INTEGER}  </select>  <!-- <select id="selectTeacerById" parameterType="int" resultMap="TeacherMap">  select * from teacher where id=#{id,javaType=int,jdbcType=INTEGER}  </select> -->  <select id="selectAll" resultMap="TeacherMap">  select t.*,s.id student_id,s.age s_age,s.sex s_sex,s.teacher_id s_teacher_id,s.student_name,  c.id cource_id,c.cource_name,c.teacher_id c_teacher_id  from teacher t join cource c on t.id=c.teacher_id left outer join student  s on t.id=s.teacher_id  </select>  <insert id="addTeacher" parameterMap="paraMap">  insert into teacher(  <include refid="teacherSql" />  )values(  #{id,javaType=int,jdbcType=INTEGER},  #{teacherName,javaType=String,jdbcType=VARCHAR},  #{age,javaType=int,jdbcType=INTEGER},  #{sex,javaType=int,jdbcType=INTEGER}  )  </insert>  </mapper>

以上就是三者的映射关系，在这里对于student.xml和cource.xml我不想过多的去说，大家注意resultMap，resultType,paramType,paramMap这四个属***的不同就行

我重点讲一下teacher.xml文件中的映射关系，这里面涉及到collection和association这两个元素，这两个元素分别代表者1对多和1对1的关系，需要注意的是，

查询的结果总不要有相同的字段名，如果存在相同的字段名会覆盖，从而导致查询的结果不对。

5、对应的Dao接口

GenericDao:

package com.mall.dubbo.dao;  public interface GenericDao {  }

该接口是所有的dao接口的父接口，对于与配置文件中的markerInterface

CourceDao:

package com.mall.dubbo.dao;  import org.springframework.stereotype.Repository;  import com.mall.dubbo.entity.Cource;  @Repository  public interface CourceDao extends GenericDao {  public abstract void addCource(Cource cource);  public abstract Cource selectById(int id);  public abstract void updateCourceById(Cource cource);  }

StudentDao:

package com.mall.dubbo.dao;  import com.mall.dubbo.entity.Student;  @Repository  public interface StudentDao extends GenericDao {  public abstract void addStudent(Student student);  }

TeacherDao:

package com.mall.dubbo.dao;  import java.util.List;  import org.springframework.stereotype.Repository;  import com.mall.dubbo.entity.Teacher;  @Repository  public interface TeacherDao extends GenericDao{  public abstract void addTeacher(Teacher teacher);  public abstract Teacher selectTeacerById(int id);  public abstract List<Teacher> selectAll();  }

6、编写测试类

CourceTest.java:

package com.mall.dubbo.test;  import org.junit.Test;  import org.springframework.context.ApplicationContext;  import org.springframework.context.support.FileSystemXmlApplicationContext;  import com.mall.dubbo.dao.CourceDao;  import com.mall.dubbo.entity.Cource;  public class CourceTest {  private ApplicationContext context = new FileSystemXmlApplicationContext("classpath:spring-mybatis.xml");  @Test  public void addCource(){  Cource cource = new Cource();  cource.setCourceName("English");  cource.setId(2);  cource.setTeacherId(1);  CourceDao dao = context.getBean(CourceDao.class);  dao.addCource(cource);  }  //@Test  public void getCourceById(){  CourceDao dao = context.getBean(CourceDao.class);  Cource c = dao.selectById(1);  System.out.println(c);  }  //@Test  public void updateCourceById(){  Cource cource = new Cource();  cource.setCourceName("France");  cource.setId(1);  cource.setTeacherId(2);  CourceDao dao = context.getBean(CourceDao.class);  dao.updateCourceById(cource);  }  }

StudentTest.java:

package com.mall.dubbo.test;  import org.junit.Test;  import org.springframework.context.ApplicationContext;  import org.springframework.context.support.FileSystemXmlApplicationContext;  import com.mall.dubbo.dao.StudentDao;  import com.mall.dubbo.entity.Student;  public class StudentTest {  ApplicationContext context = new FileSystemXmlApplicationContext("classpath:spring-mybatis.xml");  StudentDao dao = context.getBean(StudentDao.class);  @Test  public void addStudentTest(){  Student stu = new Student();  stu.setAge(21);  stu.setId(3);  stu.setSex(1);  stu.setStudentName("zhangqi");  stu.setTeacherId(1);  dao.addStudent(stu);  }  }

TeacherTest.java:

package com.mall.dubbo.test;  import java.util.List;  import org.junit.Test;  import org.springframework.context.ApplicationContext;  import org.springframework.context.support.FileSystemXmlApplicationContext;  import com.mall.dubbo.dao.TeacherDao;  import com.mall.dubbo.entity.Cource;  import com.mall.dubbo.entity.Student;  import com.mall.dubbo.entity.Teacher;  public class TeacherTest {  ApplicationContext context = new FileSystemXmlApplicationContext("classpath:spring-mybatis.xml");  TeacherDao dao = context.getBean(TeacherDao.class);  //@Test  public void addTeacherTest(){  Teacher t = new Teacher();  t.setAge(45);  t.setId(1);  t.setSex(0);  t.setTeacherName("liusanming");  dao.addTeacher(t);  }  @Test  public void getTeacherById(){  Teacher t = dao.selectTeacerById(1);  Cource c = t.getCource();  List<Student> stus = t.getStudents();  System.out.println(stus+","+stus.size());  System.out.println(c);  System.out.println(t);  }  //@Test  public void getTeachers(){  List<Teacher> ts = dao.selectAll();  System.out.println(ts.size());  Teacher t = ts.get(0);  Cource c = t.getCource();  List<Student> stus = t.getStudents();  System.out.println(stus+","+stus.size());  System.out.println(c);  System.out.println(t);  }  }

到此整个的开发过程就结束了，内容有点多，希望能够对大家有帮助。大家如果有什么问题，请留言！

本人也毕业未满一年，如果讲的有什么不对的地方，请指正，我们一块进步，谢谢！