Hibernate 多对多关联映射对象级联增删改查示例

客官°小女子只卖身不卖艺 2022-06-07 09:18 150阅读 0赞

**这里主要用教师和学生做示例开发,一个教师可以教多个学生,一个学生也可以学多个老师教的课程,所以二者是多对多的映射关系,这里我写一个例子,作级联增删改查操作.**

**代码:**

**\#数据模型层**

**Teacher.java**

package com.sunline.entity;
    
    import java.util.HashSet;
    import java.util.Set;
    
    
    /**
     * Teacher entity. @author MyEclipse Persistence Tools
     */
    
    public class Teacher  implements java.io.Serializable {
    
    
        // Fields    
    
         private Integer id;
         private Set<Student> Students = new HashSet<Student>();
         private String name;
    
    
        // Constructors
    
        /** default constructor */
        public Teacher() {
        }
    
    	/** minimal constructor */
        public Teacher(String name) {
            this.name = name;
        }
        
        /** full constructor */
        public Teacher(Set Students, String name) {
            this.Students = Students;
            this.name = name;
        }
    
       
        // Property accessors
    
        public Integer getId() {
            return this.id;
        }
        
        public void setId(Integer id) {
            this.id = id;
        }
    
        public Set getStudents() {
            return this.Students;
        }
        
        public void setStudents(Set Students) {
            this.Students = Students;
        }
    
        public String getName() {
            return this.name;
        }
        
        public void setName(String name) {
            this.name = name;
        }
       
    }

**teacher.hbm.xml**

<?xml version="1.0" encoding="utf-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
    
    <hibernate-mapping>
        <class name="com.sunline.entity.Teacher" table="teacher" catalog="association">
            <id name="id" type="java.lang.Integer">
                <column name="id" />
                <generator class="increment"></generator>
            </id>
            
              
    		<set name="Students" table="stu_tea" inverse="false" cascade="save-update" lazy="false">
    			<key column="tea_id"></key>
    			<many-to-many class="com.sunline.entity.Student" column="stu_id"></many-to-many>
    		</set>
            <property name="name" type="java.lang.String">
                <column name="name" length="60" not-null="true" />
            </property>
        </class>
    </hibernate-mapping>

**Student.java**

package com.sunline.entity;
    
    import java.util.HashSet;
    import java.util.Set;
    
    
    /**
     * Student entity. @author MyEclipse Persistence Tools
     */
    
    public class Student  implements java.io.Serializable {
    
    
        // Fields    
    
         private Integer id;
         private Set<Teacher> Teachers = new HashSet<Teacher>();
         private String name;
    
    
        // Constructors
    
        /** default constructor */
        public Student() {
        }
    
    	/** minimal constructor */
        public Student(String name) {
            this.name = name;
        }
        
        /** full constructor */
        public Student(Set Teachers, String name) {
            this.Teachers = Teachers;
            this.name = name;
        }
    
       
        // Property accessors
    
        public Integer getId() {
            return this.id;
        }
        
        public void setId(Integer id) {
            this.id = id;
        }
    
        public Set getTeachers() {
            return this.Teachers;
        }
        
        public void setTeachers(Set Teachers) {
            this.Teachers = Teachers;
        }
    
        public String getName() {
            return this.name;
        }
        
        public void setName(String name) {
            this.name = name;
        }
    }

**Student.hbm.xml**

<?xml version="1.0" encoding="utf-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
    
    <hibernate-mapping>
        <class name="com.sunline.entity.Student" table="student" catalog="association">
            <id name="id" type="java.lang.Integer">
                <column name="id" />
                <generator class="increment"></generator>
            </id>
            <set name="Teachers" table="stu_tea" cascade="save-update">
                <key column="stu_id"></key>
               <many-to-many class="com.sunline.entity.Teacher" column="tea_id"></many-to-many>
            </set>
            <property name="name" type="java.lang.String">
                <column name="name" length="40" not-null="true" />
            </property>
        </class>
    </hibernate-mapping>

**\#数据访问层**

**TeacherDao.java**

package com.sunline.dao;
    
    import javax.annotation.Resource;
    
    import org.hibernate.SessionFactory;
    import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
    import org.springframework.stereotype.Repository;
    
    import com.sunline.entity.Teacher;
    
    @Repository(value="teacherDao")
    public class TeacherDao extends HibernateDaoSupport {
    	/*
    	 * 使用注解必须添加以下方式
    	 */
        @Resource  
        public void setSessionFacotry(SessionFactory sessionFacotry) {  
            super.setSessionFactory(sessionFacotry);  
        }  
        
    	/*
    	 * 添加教师信息
    	 */
        public void AddTeacher(Teacher teacher){
    	    System.out.println("成功添加教师信息");
    		this.getHibernateTemplate().save(teacher);
        }
        
    	/*
    	 * 查询id为XX的所有教师信息
    	 */
    	public Teacher findById(int id) {
    		Teacher teacher=(Teacher)this.getHibernateTemplate().get(Teacher.class,id);
    		return teacher;
    	}
    	
    	/*
    	 * 根据id级联删除教师信息
    	 */
    	public void DeleteTeacher(int id){
    		System.out.println("成功删除数据!");
    		this.getHibernateTemplate().delete(findById(id));
    	}
    	
    	/*
    	 * 修改教师姓名
    	 */
    	public void UpdateName(String name, int id){
    		System.out.println("成功修改数据!");
    		this.getHibernateTemplate().bulkUpdate("update Teacher set name = ? where id = ?",new Object[]{name,id}) ;
    	}
    }

**\#业务逻辑层**

**TeacherBiz.java**

package com.sunline.biz;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.stereotype.Service;
    
    import com.sunline.dao.TeacherDao;
    import com.sunline.entity.Teacher;
    
    @Service(value="teacherBiz")
    public class TeacherBiz {
    	
    	/*
    	 * 添加部门
    	 */
    	@Autowired
    	@Qualifier("teacherDao")            //使用@Qualifier注解来说明使用哪一个实现类
        TeacherDao teacherDao;
        public void AddTeacher(Teacher teacher){
           teacherDao.AddTeacher(teacher);
        }
        
    	/*
    	 * 查询id为XX的所有学生信息
    	 */
    	public Teacher findById(int id) {
    		return teacherDao.findById(id);
    	}
    	
    	/*
    	 * 根据id级联删除教师信息
    	 */
    	public void DeleteTeacher(int id){
    		teacherDao.DeleteTeacher(id);
    	}
    	
    	/*
    	 * 修改教师姓名
    	 */
    	public void UpdateName(String name, int id){
    		teacherDao.UpdateName(name, id);
    	}
    }

**\#测试类**

**AddTest.java(级联添加)**

package com.sunline.test;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.transaction.annotation.Propagation;
    import org.springframework.transaction.annotation.Transactional;
    
    import com.sunline.biz.TeacherBiz;
    import com.sunline.entity.Student;
    import com.sunline.entity.Teacher;
    
    @Transactional(propagation=Propagation.REQUIRED)
    public class AddTest {
    
    	/**
    	 * @param args
    	 */
    	@SuppressWarnings("unchecked")
    	@Transactional(propagation=Propagation.REQUIRED)        //用事务管理做双重保障
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
            ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
            TeacherBiz teacherBiz = (TeacherBiz) ctx.getBean("teacherBiz");
            
            Teacher teacher1 = new Teacher();
            teacher1.setName("杨老师");
            
            Teacher teacher2 = new Teacher();
            teacher2.setName("刘老师");
            
            Student student1 = new Student();
            student1.setName("小张");
            
            Student student2 = new Student();
            student2.setName("晓林");
            
            Student student3 = new Student();
            student3.setName("杨旭");
            
            teacher1.getStudents().add(student1);
            teacher1.getStudents().add(student3);
            teacher2.getStudents().add(student1);
            teacher2.getStudents().add(student2);
            
            teacherBiz.AddTeacher(teacher1);
            teacherBiz.AddTeacher(teacher2);
    	}
    
    }

**DeleteTest.java(级联删除)**

package com.sunline.test;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.transaction.annotation.Propagation;
    import org.springframework.transaction.annotation.Transactional;
    
    import com.sunline.biz.StudentBiz;
    import com.sunline.biz.TeacherBiz;
    import com.sunline.entity.Student;
    import com.sunline.entity.Teacher;
    
    @Transactional(propagation=Propagation.REQUIRED)
    public class DeleteTest {
    
    	/**
    	 * @param args
    	 */
    	@SuppressWarnings("unchecked")
    	@Transactional(propagation=Propagation.REQUIRED)        //用事务管理做双重保障
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
            ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
            TeacherBiz teacherBiz = (TeacherBiz) ctx.getBean("teacherBiz");
    //        StudentBiz studentBiz = (StudentBiz) ctx.getBean("studentBiz");
            
    //        Student student = studentBiz.findById(1);
            Teacher teacher = teacherBiz.findById(3);
            teacher.getStudents().clear();// 解除与这老师有关联关系的所有学生，所有，可能移除多条关联关系，也有可能一条都没有或只有一条关联关系  
    //        teacher.getStudents().remove(student);      //从老师方移除与该学生有关的关联关系，仅仅移除一条关联关系  
            teacherBiz.DeleteTeacher(3);
    	}
    
    }

**UpdateTest.java(改)**

**QueryTest.java(级联查找)**

package com.sunline.test;
    
    import java.util.Set;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.transaction.annotation.Propagation;
    import org.springframework.transaction.annotation.Transactional;
    
    import com.sunline.biz.TeacherBiz;
    import com.sunline.entity.Student;
    import com.sunline.entity.Teacher;
    
    @Transactional(propagation=Propagation.REQUIRED)
    public class QueryTest {
    
    	/**
    	 * @param args
    	 */
    	@SuppressWarnings("unchecked")
    	@Transactional(propagation=Propagation.REQUIRED)        //用事务管理做双重保障
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
            ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
            TeacherBiz teacherBiz = (TeacherBiz) ctx.getBean("teacherBiz");
            
            Teacher teacher = teacherBiz.findById(2);    
            Set<Student> set = teacher.getStudents();
            for(Student student : set){
            	System.out.println("该老师教的学生有: " +student.getId()+" " + student.getName());  
            }
    	}
    
    }