知识是用来运用的，一辈子用不上的等于没学，学了忘了的等于没学，学了不会用的等于没学

 

//TreeSetDemo2.java

package saturday2;

import java.util.HashSet;

import java.util.Iterator;

import java.util.TreeSet;

public class TreeSetDemo2 {

public static void main(String[] args) {

TreeSet<Student> t=new TreeSet<Student>();

Student s1 = new Student("liudehua",52);

Student s2 = new Student("chenglong",60);

Student s3 = new Student("zhouxingchi",44);

Student s4 = new Student("sunyang",34);

Student s5 = new Student("lingqingxia",36);

Student s6 = new Student("lingqingxia",26);

Student s7 = new Student("lingqing",26);

t.add(s1);

t.add(s2);

t.add(s3);

t.add(s4);

t.add(s5);

t.add(s6);

t.add(s7);

for(Student st:t){

System.out.println(st);

}

System.out.println("==================");

System.out.println("华丽的分割线");

System.out.println("==================");

Iterator<Student> iterator1 = t.iterator();

while(iterator1.hasNext()){

System.out.println(iterator1.next());

}

}

}

 

//Student.java

 

package saturday2;

 

public class Student  implements java.lang.Comparable {//实现Comparable接口，对对象数组排序

private String name;

private int age;

public Student(){

super();

}

public Student(String name, int age){

super();

this.name = name;

this.age = age;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public boolean equals(Object obj){

if(this==obj){

return true;

}

if(!(obj instanceof Student)){

return false;

}

Student s = (Student) obj;

return(this.age==s.age);

}

@Override

 public int compareTo(Object o){      // 实现 Comparable 接口的抽象方法，定义排序规则

            Student p = (Student)o;

            return this.age - p.age;                      // 升序排列，反之降序

     }

@Override

public String toString(){

return("Student  [name="+name+",age="+age+"]");

}

}