student类源码

public class Student {

 public String id;

 public String name;

 public Set<Course> courses; //存储学生课程信息

 @Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + ((name == null) ? 0 : name.hashCode());

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (!(obj instanceof Student))

return false;

Student other = (Student) obj;

if (name == null) {

if (other.name != null)

return false;

} else if (!name.equals(other.name))

return false;

return true;

}

public Student(String id,String name){

this.id=id;

this.name=name;

this.courses = new HashSet<Course>();//实例化

 }

}

看一下你student类是什么定义的？你发一下student源代码