【Java每日一题】20161229

package Dec2016;  

import java.util.ArrayList;
import java.util.List;  

public class Ques1229 {  

   public static void main(String[] args){
       Student stu01 = new Student("001");
       Student stu02 = new Student(null);  

       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null："+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;
    }
}  

今日问题： 
请问主程序输出结果是什么？（点击以下“【Java每日一题】20161229”查看20161228问题解析）

题目原发布于公众号、简书：【Java每日一题】20161229，【Java每日一题】20161229