存储学生对象，按年龄大小排序，保证唯一性 - 黑马程序员技术交流社区

package treesetdemo;
/**
* 定义学生对象，其可进行年龄大小的比较，所以需要实现Comparable接口
* */
public class Student implements Comparable<Student>{
private String name;
private int age;
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;
}
//复写Comparable中的compareTo方法
//返回正数则是自然升序负数为降序 0 则认为是是同一元素
@Override
public int compareTo(Student o) {
// TODO Auto-generated method stub
int result = this.age - o.age; //比较年龄大小
if(result == 0){
result = this.name.compareTo(o.name);//当年龄相同时，按姓名自然排序排
}
return result;
}
}
package treesetdemo;
import java.util.TreeSet;
public class TreeSetDemo1 {
/**
* 需求：存储自定义的学生对象，并保证元素的唯一性，并按照年龄从小到大排序
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//建立TreeSet
TreeSet<Student> ts = new TreeSet<Student>();
//建立学生对象
Student s1 = new Student("uiui",18);
Student s2 = new Student("haha",22);
Student s3 = new Student("gege",12);
Student s4 = new Student("Lili",18);
Student s5 = new Student("Licu",13);
Student s6 = new Student("Lili",18);
//添加对象
ts.add(s1);
ts.add(s2);
ts.add(s3);
ts.add(s4);
ts.add(s5);
ts.add(s6);
//遍历集合
for(Student s: ts){
System.out.println(s.getName()+"..."+s.getAge());
}
}
}

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