public class Student {

public String id;
public String name;
public Student() {
}
public Student(String id,String name) {
this.id = id;
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public boolean equals(Object obj) {
Student s=(Student)obj; 
return id.equals(s.id) && name.equals(s.name); 
}
@Override
public int hashCode() {
String in = id + name;
return in.hashCode();
}
}

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class QuSame {
 
 public static void main(String[] args) {
 List<Student> stu = new ArrayList<Student>();
 stu.add(new Student("1","yi"));
 stu.add(new Student("3","san"));
 stu.add(new Student("3","san"));
 stu.add(new Student("2","er"));
 stu.add(new Student("2","er"));
 //set集合保存的是引用不同地址的对象
 Set<Student> ts = new HashSet<Student>();
 ts.addAll(stu);
 
 for (Student student : ts) {
  System.out.println(student.getId()+"-"+student.getName());
 }
 }
}