大哥们帮帮看看错在哪里 hibernate Annotation 老师 学生 的多对多双向
这是两个实体类，分别是学生和老师


这是错误信息
org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: com.model.Teacher.students




老师类

Java code

package com.model;import java.util.HashSet;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.ManyToMany;@Entitypublic class Teacher {    private int id;    private String name;    private HashSet<Student> students = new HashSet<Student>();    @Id    @GeneratedValue    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;    }    @ManyToMany    public HashSet<Student> getStudents() {        return students;    }    public void setStudents(HashSet<Student> students) {        this.students = students;    }}

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学生类

Java code

package com.model;import java.util.HashSet;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.ManyToMany;@Entitypublic class Student {    private int id;    private String name;    private HashSet<Teacher> teahcers = new HashSet<Teacher>();        @ManyToMany(mappedBy="students")    public HashSet<Teacher> getTeahcers() {        return teahcers;    }    public void setTeahcers(HashSet<Teacher> teahcers) {        this.teahcers = teahcers;    }    @Id    @GeneratedValue    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;    }    }

[解决办法]
看代码好似乎没问题哦。不知道那里有问题。
[解决办法]

探讨

发现在问题了：

集合必要为Set ,我弄成HashSet了。

大家可以试一下我这个，看看。

[解决办法]
最好不要用“ManyToMany”，因为中间表往往还有其他字段。
[解决办法]
Hibernate 中不能使用实体类的，要用接口