标签：blog http color os io 使用 java ar for
一如Hibernate中的两个对象之间的关系在MyBatis中也关于两个对象之间的关联关系的描述！好了不多说，直接进入正题。
为了测试数据简单使用表的字段较少！
student：id，name，supervisor_id
teacher：id，name
项目结构截图
项目中引入包的截图
com,iss.model.Student
public class Student {
private int id;
private String name;
private Teacher supervisor;
public Teacher getSupervisor() {
return supervisor;
}
public void setSupervisor(Teacher supervisor) {
this.supervisor = supervisor;
}
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;
}
}
package com.iss.model;
import java.util.ArrayList;
import java.util.List;
public class Teacher {
private int id;
private String name;
// private Set<Student> students = new HashSet<Student>();
private List<Student> students = new ArrayList<Student>();
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 List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
// public Set<Student> getStudents() {
// return students;
// }
//
// public void setStudents(Set<Student> students) {
// this.students = students;
// }
}
package com.iss.dao;
import com.iss.model.Student;
public interface StudentMapper {
public Student getById(int id);
public void addStudent(Student student);
}
package com.iss.dao;
import com.iss.model.Teacher;
public interface TeacherMapper {
public void addTeacher(Teacher teacher);
public Teacher getById(int id);
}
com,iss,dao,StudentMapper.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.iss.dao.StudentMapper">
<!--查询数据 -->
<select id="getById" parameterType="int" resultMap="studentResultMap">
select s.name,t.name from student s,teacher t where
s.supervisor_id=t.id
and s.id=#{id}
<!-- select name from student where id=#{id} -->
</select>
<!--学生实体映射 -->
<resultMap type="Student" id="studentResultMap">
<result property="id" column="id" />
<result property="name" column="name" />
<!-- <association property="supervisor" javaType="Teacher"> <result property="id"
column="id" /> <result property="name" column="name" /> </association> -->
<association property="supervisor"
resultMap="com.iss.dao.TeacherMapper.supervisorResultMap"></association>
</resultMap>
<!--插入数据 -->
<insert id="addStudent" useGeneratedKeys="true" parameterType="User"
keyProperty="id">
insert into student
values(#{id},#{name},#{supervisor.id})
</insert>
</mapper>com.iss.dao,TeacherMapper.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.iss.dao.TeacherMapper">
<!--增加老师 -->
<insert id="addTeacher" useGeneratedKeys="true" parameterType="Teacher"
keyProperty="id">
insert into teacher values(#{id},#{name});
</insert>
<!--查询老师 -->
<select id="getById" parameterType="int" resultMap="supervisorResultMap">
select t.id
t_id,
t.name t_name,s.name from student s,teacher t where
s.supervisor_id=t.id and
t.id=#{id}
</select>
<!-- 教师实体映射 -->
<resultMap type="Teacher" id="supervisorResultMap">
<result property="id" column="t_id" />
<result property="name" column="t_name" />
<collection property="students"
resultMap="com.iss.dao.StudentMapper.studentResultMap"></collection>
</resultMap>
</mapper>
下面看一下Spring和Mybatis整合的配置文件
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>
<!-- 把数据源交给Spring管理 -->
<!-- <mappers>
<mapper resource="com/iss/dao/UserMapper.xml" />
</mappers> -->
</configuration>
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:aop="http://www.springframework.org/schema/aop" 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-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/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <!-- 配置数据源 --> <bean id="jdbcDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"> <value>org.gjt.mm.mysql.Driver</value> </property> <property name="url"> <value>jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8 </value> </property> <property name="username"> <value>root</value> </property> <property name="password"> <value>root</value> </property> </bean> <!--配置SqlSessionFactory --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="jdbcDataSource" /> <property name="typeAliasesPackage" value="com.iss.model"></property> <!-- <property name="configLocation" value="classpath:mybatis-config.xml"></property> --> </bean> <!-- <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean"> <property name="mapperInterface" value="com.iss.dao.UserMapper"></property> <property name="sqlSessionFactory" ref="sqlSessionFactory"></property> </bean> --> <!-- MappperScannerConfigure:扫描特定的包自动创建成批地映射器。 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.iss.dao"></property> </bean> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="jdbcDataSource" /> </bean> <!--配置事务处理策略，transaction-manager属性指定事务管理器。 若事务管理器bean的id即为transactionManager，则 transaction-manager的属性可以不指定 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <!--所有以find开头的方法都是只读的 --> <tx:method name="get*" read-only="true" /> <tx:method name="add*" /> <!--其他方法使用默认事务策略 --> <tx:method name="*" /> </tx:attributes> </tx:advice> <!-- AOP配置 --> <aop:config> <!--pointcut元素定义一个切入点，execution中的第一个星号 用以匹配方法的返回类型，这里星号表明匹配所有返回类型。 com.abc.dao.*.*(..)表明匹配com.abc.dao包下的所有类的所有 方法 --> <aop:pointcut id="myPointcut" expression="execution(* com.iss.dao.*.*(..))" /> <!--将定义好的事务处理策略应用到上述的切入点 --> <aop:advisor advice-ref="txAdvice" pointcut-ref="myPointcut" /> </aop:config> </beans>
package com.iss.test;
import java.util.List;
import java.util.Set;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.iss.dao.StudentMapper;
import com.iss.dao.TeacherMapper;
import com.iss.dao.UserMapper;
import com.iss.model.Student;
import com.iss.model.Teacher;
import com.iss.model.User;
public class Test {
public static void main(String[] args) {
ApplicationContext ctx = null;
ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
StudentMapper studentMapper = (StudentMapper) ctx
.getBean("studentMapper");
TeacherMapper teacherMapper = (TeacherMapper) ctx
.getBean("teacherMapper");
Teacher teacher = teacherMapper.getById(1);
List<Student> students = teacher.getStudents();
System.out.println(students.size());
for (Student stu : students) {
System.out.println(stu.getSupervisor().getName());
}
}
}
标签：blog http color os io 使用 java ar for
原文地址：http://blog.csdn.net/wangdianyong/article/details/39134555
