package Dec2016;  

import java.util.ArrayList;

import java.util.List;  

public class Ques1228 {  

    public static void main(String[] arg){

        Student stu01 = new Student("001");

        Student stu02 = new Student("001 ");  // stu02中001后面有个空格  

        List<Student> students = new ArrayList<Student>();

        students.add(stu01);

        students.add(stu02);

        System.out.println("students是否包含001学号："+students.contains(stu01));

        System.out.println("students是否包含002学号："+students.contains(stu02));

    }

}  

class Student{

    private String stuId;  

    public Student(String stuId) {

        super();

        this.stuId = stuId;

    }  

    public String getStuId() {

        return stuId;

    }

    public void setStuId(String stuId) {

        this.stuId = stuId;

    }  

    @Override

    public boolean equals(Object obj) {

        if(obj instanceof Student){

            Student stu = (Student) obj;

            return stuId.equalsIgnoreCase(stu.getStuId().trim());

        }

        return false;

    }

}