Hibernate 注解 实现一对多

首先，我们知道，班级与学生是一对多关系。笔者就以此来编写Hibernate注解实现一对多关系。

先上【班级】类：Clazz.java （这里千万不要用class，否则你懂得。。。），代码如下：

package com.zhang.shun.entity;import java.util.Set;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.OneToMany;import javax.persistence.Table;@Entity@Table(name="CLAZZ")public class Clazz {private int id;private String name;private Set<Student> student;@Id            @GeneratedValue public int getId() {return id;}public void setId(int id) {this.id = id;}@Column(name="c_name",length=20)public String getName() {return name;}public void setName(String name) {this.name = name;}@OneToMany(mappedBy="clazz")//@JoinColumn(name="s")public Set<Student> getStudent() {return student;}public void setStudent(Set<Student> student) {this.student = student;}}

下面是Student.java。代码如下：

package com.zhang.shun.entity;import java.util.Set;import javax.persistence.Column;import javax.persistence.Entity;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.Table;@Entity@Table(name="STUDENT")public class Student {private int id;private String name;private Clazz clazz;private Set<Course> course;        @Id@GeneratedValuepublic int getId() {return id;}public void setId(int id) {this.id = id;}@Column(name="s_name",length=20)public String getName() {return name;}public void setName(String name) {this.name = name;}@ManyToOne(targetEntity=Clazz.class)@JoinColumn(name="c_id")public Clazz getClazz() {return clazz;}public void setClazz(Clazz clazz) {this.clazz = clazz;}/*@ManyToMany@JoinTable(name="stu_cour", joinColumns={@JoinColumn(name="s_id")}, inverseJoinColumns={@JoinColumn(name="c_id")}  )public Set<Course> getCourse() {return course;}public void setCourse(Set<Course> course) {this.course = course;}*/}

就这两个类即可实现。。。