映射关系级别注解

Posted 黄小鱼ZZZ

tags:

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映射关系级别注解

   一对一单向外键

           @OneToOne(cascade=CascadeType.ALL)
@JoinColumn(name="pid",unique=true)
注意：保存时应该先保存外键对象，在保存主表对象
   实例：将环境配置好，所需要的包前边已经提到过，

      学生实体类：
            
package com.oto;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private IdCard card;//身份证
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         
         public Students(){
        	 
         }

		public Students(IdCard card,  String gender,
				Date date, String major) {
//			super();
			this.card = card;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
        
		@OneToOne(cascade=CascadeType.ALL)
		@JoinColumn(name="pid",unique=true)
		public IdCard getCard() {
			return card;
		}

		public void setCard(IdCard card) {
			this.card = card;
		}


         
}

身份证实体类：
package com.oto;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

import org.hibernate.annotations.GenericGenerator;

@Entity
public class IdCard {
	     @Id
	     @GeneratedValue(generator="pid")
	     @GenericGenerator(name="pid",strategy="assigned")
	     @Column(length=18)
         private String pid; //身份证号
         private String sname;//姓名
         
         public IdCard(){
        	 
        	 
         }
         
         
		public IdCard(String pid, String sname) {
			this.pid = pid;
			this.sname = sname;
		}


		public String getPid() {
			return pid;
		}
		public void setPid(String pid) {
			this.pid = pid;
		}
		public String getSname() {
			return sname;
		}
		public void setSname(String sname) {
			this.sname = sname;
		}
         
         
}
测试类：
   
package com.oto;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	//往数据库中添加学生数据
	@Test
	public void addStudents(){
		  //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
       //创建会话
 	   Session session = sessionFactory.getCurrentSession();
 	   //创建事务
 	   Transaction tx = session.beginTransaction();
 	   IdCard card = new IdCard("123456789012345678","猪八戒");
 	   Students stu = new Students(card,"男",new Date(),"计算机");
 	   session.save(card);
 	   session.save(stu);
 	   tx.commit();
	}
}

hibernate.cfg.xml中的配置：下面的使用的是同一个配置，下边的代码中不再列举，
       
<!DOCTYPE hibernate-configuration PUBLIC
	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
	<session-factory>
	<property name="hibernate.dialect">org.hibernate.dialect.mysqlDialect</property>
		<!-- 
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="hibernate.connection.url">jdbc:mysql:///hibernate_struts_stumanager</property>
		 -->
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mypage</property>
		
		
		<property name="hibernate.connection.username">root</property>
		<property name="hibernate.connection.password">root</property>
		<property name="hibernate.show_sql">false</property>
		<property name="hibernate.hbm2ddl.auto">create</property>
		<property name="current_session_context_class">thread</property>
		<!-- <mapping class="com.oto.Students"/>
		<mapping class="com.oto.IdCard"/> --><!-- 一对一单向外键关联 -->
		
		<!-- <mapping class="com.oto_11.Students"/>
		<mapping class="com.oto_11.IdCard"/>  -->        <!--一对一双向外键关联  -->
		
		<!-- <mapping class="com.mto.Students"/>
		<mapping class="com.mto.ClassRoom"/> --><!--  多对一单向外键关联-->
		
		<!-- <mapping class="com.otm.Students"/>
		<mapping class="com.otm.ClassRoom"/> --><!-- 一对多单向外键关联 -->
		
		<!-- <mapping class="com.otm_11.Students"/>
		<mapping class="com.otm_11.ClassRoom"/> --><!-- 一对多双向外键 -->
		
		<!-- <mapping class="com.mtm.Students"/>
		<mapping class="com.mtm.Teachers"/>  --> <!-- 多对多单向外键关联 -->
		
		<mapping class="com.mtm_11.Students"/>
		<mapping class="com.mtm_11.Teachers"/>   <!-- 多对多双向外键关联 -->
	</session-factory>
</hibernate-configuration>

一对一双向外键关联

主控方的配置同一对一单向外键关联
@OneToOne(mappedBy="card")//被控方
双向关联，必须设置mappedBy属性。因为双向关联只能交给一方去控制，不可能在双方
都设置外键保存关联关系，否则双方都无法保存
实例：
       学生实体类
 
package com.oto_11;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private IdCard card;//身份证
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         
         public Students(){
        	 
         }

		public Students(IdCard card,  String gender,
				Date date, String major) {
//			super();
			this.card = card;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
        
		@OneToOne(cascade=CascadeType.ALL)
		@JoinColumn(name="pid",unique=true)
		public IdCard getCard() {
			return card;
		}

		public void setCard(IdCard card) {
			this.card = card;
		}


         
}

身份证实体类：
    
package com.oto_11;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToOne;

import org.hibernate.annotations.GenericGenerator;

@Entity
public class IdCard {
	     @Id
	     @GeneratedValue(generator="pid")
	     @GenericGenerator(name="pid",strategy="assigned")
	     @Column(length=18)
         private String pid; //身份证号
         private String sname;//姓名
         
         @OneToOne(mappedBy="card")
         private Students stu;
         
         public IdCard(){
        	 
        	 
         }
         
         
		public IdCard(String pid, String sname) {
			this.pid = pid;
			this.sname = sname;
		}


		public Students getStu() {
			return stu;
		}


		public void setStu(Students stu) {
			this.stu = stu;
		}


		public String getPid() {
			return pid;
		}
		public void setPid(String pid) {
			this.pid = pid;
		}
		public String getSname() {
			return sname;
		}
		public void setSname(String sname) {
			this.sname = sname;
		}
         
         
}
测试类：
   
package com.oto_11;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	@Test
	public void addStudents(){
		  //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
       //创建会话
 	   Session session = sessionFactory.getCurrentSession();
 	   //创建事务
 	   Transaction tx = session.beginTransaction();
 	   IdCard card = new IdCard("123456789012345678","猪八戒");
 	   Students stu = new Students(card,"男",new Date(),"计算机");
 	   session.save(card);
 	   session.save(stu);
 	   tx.commit();
	}
}

                一对一单向外键联合主键
一对一双向外键联合主键

 创建主键类
主键类必须实现serializable接口，重写hashCode()和equals()方法。
主键类
     @Embeddable
实体类
     @EmbeddedId
                

多对一单向外键关联

       多方持有一方的引用
  @ManyToOne(cascade={CascadeType.ALL},
  fetch=FetchType.EAGER)
  @JoinColumn(name="cid",referencedColumnName="CID")
学生实体类：
 
package com.mto;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         private ClassRoom classroom;
         private String sname;
         
         public Students(){
        	 
         }

		public Students(String sname,  String gender,
				Date date, String major) {
//			super();
            this.sname = sname;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getSname() {
			return sname;
		}

		public void setSname(String sname) {
			this.sname = sname;
		}

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
		@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)
		@JoinColumn(name="cid",referencedColumnName="CID")
		public ClassRoom getClassroom() {
			return classroom;
		}

		public void setClassroom(ClassRoom classroom) {
			this.classroom = classroom;
		}


         
}

班级实体类：
 
package com.mto;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

import org.hibernate.annotations.GenericGenerator;

//班级实体类
@Entity
public class ClassRoom {
	   @Id
	   @GeneratedValue(generator="cid")
	   @GenericGenerator(name="cid",strategy="assigned")
	   @Column(length=4)
       private String cid;//班级的编号
       private String cname;//班级的名字
       
       public ClassRoom(){
    	   
       }
       
	public ClassRoom(String cid, String cname) {
		this.cid = cid;
		this.cname = cname;
	}

	public String getCid() {
		return cid;
	}
	public void setCid(String cid) {
		this.cid = cid;
	}
	public String getCname() {
		return cname;
	}
	public void setCname(String cname) {
		this.cname = cname;
	}
       
       
       
}
测试类：
  
package com.mto;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	//往数据库中添加学生数据
	@Test
	public void addStudents(){
		  //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
       //创建会话
 	   Session session = sessionFactory.getCurrentSession();
 	   //创建事务
 	   Transaction tx = session.beginTransaction();
       //创建班级对象
 	   ClassRoom c1 = new ClassRoom("0001","软件工程");
 	   ClassRoom c2 = new ClassRoom("0002","通信工程");
 	   //创建学生对象
 	   Students s1 = new Students("小王","男",new Date(),"计算机");
 	   Students s2 = new Students("小黄","男",new Date(),"计算机");
 	   Students s3 = new Students("小花","女",new Date(),"计算机");
 	   Students s4 = new Students("小红","女",new Date(),"计算机");
 	   
 	   s1.setClassroom(c1);
 	   s2.setClassroom(c1);

 	   s3.setClassroom(c2);
 	   s4.setClassroom(c2);
 	   
 	   session.save(c1);
 	   session.save(c2);
 	   session.save(s1);
 	   session.save(s2);
 	   session.save(s3);
 	   session.save(s4);
      tx.commit(); 	   
	}
}

一对多单向外键关联

 一方持有多方的集合
  @OneToMany(cascade={cascadeType.ALL},fetch=FetchType.LAZY)
  @JoinColumn(name="cid")
     实例：
学生实体类：
       
package com.otm;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         private String sname;
         
         public Students(){
        	 
         }

		public Students(String sname,  String gender,
				Date date, String major) {
//			super();
            this.sname = sname;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getSname() {
			return sname;
		}

		public void setSname(String sname) {
			this.sname = sname;
		}

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}


         
}
班级实体类：
         
package com.otm;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;

import org.hibernate.annotations.GenericGenerator;

//班级实体类
@Entity
public class ClassRoom {
	   @Id
	   @GeneratedValue(generator="cid")
	   @GenericGenerator(name="cid",strategy="assigned")
	   @Column(length=4)
       private String cid;//班级的编号
       private String cname;//班级的名字
       
       @OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY)
	   @JoinColumn(name="cid")
       private Set<Students> stus;//一方持有多方的集合
       public ClassRoom(){
    	   
       }
       
	public ClassRoom(String cid, String cname) {
		this.cid = cid;
		this.cname = cname;
	}

	public String getCid() {
		return cid;
	}
	public void setCid(String cid) {
		this.cid = cid;
	}
	public String getCname() {
		return cname;
	}
	public void setCname(String cname) {
		this.cname = cname;
	}

	public Set<Students> getStus() {
		return stus;
	}

	public void setStus(Set<Students> stus) {
		this.stus = stus;
	}
       
       
       
}

测试类：
      
package com.otm;

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	@Test
	public void addStudents(){
		  //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
       //创建会话
 	   Session session = sessionFactory.getCurrentSession();
 	   //创建事务
 	   Transaction tx = session.beginTransaction();
       //创建班级对象
 	   ClassRoom c1 = new ClassRoom("0001","软件工程");
 	   ClassRoom c2 = new ClassRoom("0002","通信工程");
 	   //创建学生对象
 	   Students s1 = new Students("小王","男",new Date(),"计算机");
 	   Students s2 = new Students("小黄","男",new Date(),"计算机");
 	   Students s3 = new Students("小花","女",new Date(),"计算机");
 	   Students s4 = new Students("小红","女",new Date(),"计算机");
 	   
 	   Set<Students> set1 = new HashSet<Students>();
 	   set1.add(s1);
 	   set1.add(s2);
 	   
 	   Set<Students> set2 = new HashSet<Students>();
 	   set2.add(s3);
 	   set2.add(s4);
 	   
 	   session.save(s1);
 	   session.save(s2);
 	   session.save(s3);
 	   session.save(s4);
 	   
 	   session.save(c1);
 	   session.save(c2);
      tx.commit(); 	   
	}
}

一对多双向外键关联

多方：多方持有一方的引用
@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)
@JoinColumn(name="cid")
一方：一方持有多方的集合
@OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY)
@JoinColumn(name="cid")
        实例：
      
package com.otm_11;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         private String sname;//姓名
         private ClassRoom classroom;
         public Students(){
        	 
         }

		public Students(String sname,  String gender,
				Date date, String major) {
//			super();
            this.sname = sname;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getSname() {
			return sname;
		}

		public void setSname(String sname) {
			this.sname = sname;
		}

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
		@ManyToOne(cascade={CascadeType.ALL},fetch=FetchType.EAGER)
		@JoinColumn(name="cid")
		public ClassRoom getClassroom() {
			return classroom;
		}

		public void setClassroom(ClassRoom classroom) {
			this.classroom = classroom;
		}

     
         
}

班级实体类：
  
package com.otm_11;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;

import org.hibernate.annotations.GenericGenerator;

//班级实体类
@Entity
public class ClassRoom {
	   @Id
	   @GeneratedValue(generator="cid")
	   @GenericGenerator(name="cid",strategy="assigned")
	   @Column(length=4)
       private String cid;//班级的编号
       private String cname;//班级的名字
       
       @OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY)
	   @JoinColumn(name="cid")
       private Set<Students> stus;//一方持有多方的集合
       public ClassRoom(){
    	   
       }
       
	public ClassRoom(String cid, String cname) {
		this.cid = cid;
		this.cname = cname;
	}

	public String getCid() {
		return cid;
	}
	public void setCid(String cid) {
		this.cid = cid;
	}
	public String getCname() {
		return cname;
	}
	public void setCname(String cname) {
		this.cname = cname;
	}

	public Set<Students> getStus() {
		return stus;
	}

	public void setStus(Set<Students> stus) {
		this.stus = stus;
	}
       
       
       
}
测试类：
 
package com.mto_11;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

import com.otm_11.ClassRoom;
import com.otm_11.Students;

public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	@Test
	public void addStudents(){
		  //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
       //创建会话
 	   Session session = sessionFactory.getCurrentSession();
 	   //创建事务
 	   Transaction tx = session.beginTransaction();
       //创建班级对象
 	   ClassRoom c1 = new ClassRoom("0001","软件工程");
 	   ClassRoom c2 = new ClassRoom("0002","通信工程");
 	   //创建学生对象
 	   Students s1 = new Students("小王","男",new Date(),"计算机");
 	   Students s2 = new Students("小黄","男",new Date(),"计算机");
 	   Students s3 = new Students("小花","女",new Date(),"计算机");
 	   Students s4 = new Students("小红","女",new Date(),"计算机");
 	   
 	   s1.setClassroom(c1);
 	   s2.setClassroom(c1);

 	   s3.setClassroom(c2);
 	   s4.setClassroom(c2);
 	   
 	   session.save(c1);
 	   session.save(c2);
 	   session.save(s1);
 	   session.save(s2);
 	   session.save(s3);
 	   session.save(s4);
      tx.commit(); 	   
	}
}

多对多单向外键关联

 其中一个多方持有另一个多方的集合对象
 创建中间表
 @MantToMany
 @JoinTable(
     name="teachers_students",
     joinColumns={@JoinColumn(name="sid")},inverseJoinColumns={@JoinColumn(name="tid")}
 )
实例：
学生实体类：
package com.mtm;

import java.util.Date;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         private String sname;//学生姓名
         private Set<Teachers> teachers; //学生持有教师的集合
         
         public Students(){
        	 
         }

		public Students(String sname,  String gender,
				Date date, String major) {
//			super();
            this.sname = sname;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getSname() {
			return sname;
		}

		public void setSname(String sname) {
			this.sname = sname;
		}

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
		 @ManyToMany
		  @JoinTable(
		      name="teachers_students",
		      joinColumns={@JoinColumn(name="sid")},
		      inverseJoinColumns={@JoinColumn(name="tid")}
		  )
		public Set<Teachers> getTeachers() {
			return teachers;
		}

		public void setTeachers(Set<Teachers> teachers) {
			this.teachers = teachers;
		}


         
}

老师实体类：
 
package com.mtm;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

import org.hibernate.annotations.GenericGenerator;

//教师实体类
@Entity
public class Teachers {
	      @Id
	      @GeneratedValue(generator="tid")
	      @GenericGenerator(name="tid",strategy="assigned")
	      @Column(length=4)
          private String tid;//教师id
          private String tname;//教师名字
          
          public Teachers(){
        	  
          }
          
          
		public Teachers(String tid, String tname) {
//			super();
			this.tid = tid;
			this.tname = tname;
		}


		public String getTid() {
			return tid;
		}
		public void setTid(String tid) {
			this.tid = tid;
		}
		public String getTname() {
			return tname;
		}
		public void setTname(String tname) {
			this.tname = tname;
		}
          
          
}

测试类：
package com.mtm;

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;


public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	@Test
	public void addStudents(){
		 //创建hibernate配置对象
	 	   Configuration config = new Configuration().configure();
	 	   //创建服务注册对象
	 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
	        //生成SessionFactory
	 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
	 	   Session session = sessionFactory.getCurrentSession();
	 	   Transaction tx = session.beginTransaction();
	 	   
	 	   //创建教师对象
	 	   Teachers t1 = new Teachers("0001","张老师");
	 	   Teachers t2 = new Teachers("0002","黄老师");
	 	   Teachers t3 = new Teachers("0003","李老师");
	 	   Teachers t4 = new Teachers("0004","王老师");
	 	   
	 	   Students s1 = new Students("张三","男",new Date(),"计算机");
	 	   Students s2 = new Students("李四","男",new Date(),"计算机");
	 	   Students s3 = new Students("王五","女",new Date(),"通信");
	 	   Students s4 = new Students("赵六","女",new Date(),"通信");
	 	   
	 	   Set<Teachers> set1 = new HashSet<Teachers>();
	 	   set1.add(t1);
	 	   set1.add(t2);
	 	   
	 	   Set<Teachers> set2 = new HashSet<Teachers>();
	 	   set2.add(t3);
	 	   set2.add(t4);
	 	   
	 	   Set<Teachers> set3 = new HashSet<Teachers>();
	 	   set3.add(t1);
	 	   set3.add(t3);
	 	   set3.add(t4);
	 	   
	 	   Set<Teachers> set4 = new HashSet<Teachers>();
	 	   set4.add(t2);
	 	   set4.add(t3);
	 	   set4.add(t4);
	 	   
	 	   s1.setTeachers(set1);
	 	   s2.setTeachers(set2);
	 	   s3.setTeachers(set3);
	 	   s4.setTeachers(set4);
	 	   
	 	   session.save(t1);
	 	   session.save(t2);
	 	   session.save(t3);
	 	   session.save(t4);
	 	   
	 	   session.save(s1);
	 	   session.save(s2);
	 	   session.save(s3);
	 	   session.save(s4);
	 	   
	 	   tx.commit();
	}
}

多对多双向外键关联

双方持有对方的集合对象，其中一方设置
 //教师类
 @ManyToMany(mappedBy="teachers")
 另一方
 //学生类
 @ManyToMany
 @JoinTable(
    name="teachers_students",
    joinColumns={@JoinColumn(name="sid")},
    inverseJoinColumns={@JoinColumn(name="tid")}
 )
实例：
学生实体类：
 
package com.mtm_11;

import java.util.Date;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Entity;//JPA注解
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;

/*
 * 学生实体类
 */
@Entity
public class Students {
         private int sid; //学号
         private String gender;//性别
         private Date birthday;//出生日期
         private String major;//专业
         private String sname;//学生姓名
         private Set<Teachers> teachers; //学生持有教师的集合
         
         public Students(){
        	 
         }

		public Students(String sname,  String gender,
				Date date, String major) {
//			super();
            this.sname = sname;
			this.gender = gender;
			this.birthday = date;
			this.major = major;
		}
        @Id
        @GeneratedValue
        public int getSid() {
			return sid;
		}

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

		public String getSname() {
			return sname;
		}

		public void setSname(String sname) {
			this.sname = sname;
		}

		public String getGender() {
			return gender;
		}

		public void setGender(String gender) {
			this.gender = gender;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public String getMajor() {
			return major;
		}

		public void setMajor(String major) {
			this.major = major;
		}
		 @ManyToMany
		  @JoinTable(
		      name="teachers_students",
		      joinColumns={@JoinColumn(name="sid")},
		      inverseJoinColumns={@JoinColumn(name="tid")}
		  )
		public Set<Teachers> getTeachers() {
			return teachers;
		}

		public void setTeachers(Set<Teachers> teachers) {
			this.teachers = teachers;
		}


         
}
老师实体类：
  
package com.mtm_11;

import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;

import org.hibernate.annotations.GenericGenerator;

//教师实体类
@Entity
public class Teachers {
	      @Id
	      @GeneratedValue(generator="tid")
	      @GenericGenerator(name="tid",strategy="assigned")
	      @Column(length=4)
          private String tid;//教师id
          private String tname;//教师名字
          
          @ManyToMany(mappedBy="teachers")
          private Set<Students> stus;//教师持有学生的集合
          
          public Teachers(){
        	  
          }
          
          
		public Teachers(String tid, String tname) {
//			super();
			this.tid = tid;
			this.tname = tname;
		}


		public String getTid() {
			return tid;
		}
		public void setTid(String tid) {
			this.tid = tid;
		}
		public String getTname() {
			return tname;
		}
		public void setTname(String tname) {
			this.tname = tname;
		}
          
          
}
测试类：
  
package com.mtm_11;

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;


public class TestStudents {
	@Test
    public void testShemaExport(){
 	   //创建hibernate配置对象
 	   Configuration config = new Configuration().configure();
 	   //创建服务注册对象
 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
        //生成SessionFactory
 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
        SchemaExport export = new SchemaExport(config);
        export.create(true,true);
    }
	@Test
	public void addStudents(){
		 //创建hibernate配置对象
	 	   Configuration config = new Configuration().configure();
	 	   //创建服务注册对象
	 	   ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(config.getProperties()).buildServiceRegistry();
	        //生成SessionFactory
	 	   SessionFactory sessionFactory = config.buildSessionFactory(serviceRegistry);
	 	   Session session = sessionFactory.getCurrentSession();
	 	   Transaction tx = session.beginTransaction();
	 	   
	 	   //创建教师对象
	 	   Teachers t1 = new Teachers("0001","张老师");
	 	   Teachers t2 = new Teachers("0002","黄老师");
	 	   Teachers t3 = new Teachers("0003","李老师");
	 	   Teachers t4 = new Teachers("0004","王老师");
	 	   
	 	   Students s1 = new Students("张三","男",new Date(),"计算机");
	 	   Students s2 = new Students("李四","男",new Date(),"计算机");
	 	   Students s3 = new Students("王五","女",new Date(),"通信");
	 	   Students s4 = new Students("赵六","女",new Date(),"通信");
	 	   
	 	   Set<Teachers> set1 = new HashSet<Teachers>();
	 	   set1.add(t1);
	 	   set1.add(t2);
	 	   
	 	   Set<Teachers> set2 = new HashSet<Teachers>();
	 	   set2.add(t3);
	 	   set2.add(t4);
	 	   
	 	   Set<Teachers> set3 = new HashSet<Teachers>();
	 	   set3.add(t1);
	 	   set3.add(t3);
	 	   set3.add(t4);
	 	   
	 	   Set<Teachers> set4 = new HashSet<Teachers>();
	 	   set4.add(t2);
	 	   set4.add(t3);
	 	   set4.add(t4);
	 	   
	 	   s1.setTeachers(set1);
	 	   s2.setTeachers(set2);
	 	   s3.setTeachers(set3);
	 	   s4.setTeachers(set4);
	 	   
	 	   session.save(t1);
	 	   session.save(t2);
	 	   session.save(t3);
	 	   session.save(t4);
	 	   
	 	   session.save(s1);
	 	   session.save(s2);
	 	   session.save(s3);
	 	   session.save(s4);
	 	   
	 	   tx.commit();
	}
}
这里列举了几个简单的例子，大神直接略过啊~~~~

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