TreeSet的使用
TreeSet的使用：请按照姓名的长度排序
public classStudent implementsComparable<Student>{
private String name;
private int age;
public Student() {
super();
// TODO Auto-generated constructor stub
}
public Student(String name, int age) {
super();
this.name = name;
this.age = age;
}
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}
/**
* @return the age
*/
public int getAge() {
return age;
}
/**
* @param age the age to set
*/
public void setAge(int age) {
this.age = age;
}
@Override
public int compareTo(Student s) {
// TODO Auto-generated method stub
//主要条件
int num = this.name.length() - s.name.length();
//姓名的长度相同，不代表姓名的内容不同
int num2 = num ==0? this.name.compareTo(s.name) : num;
//姓名的长度和内容相同，不代表年龄相同，所以还得继续判断年龄
int num3 = num2 == 0? this.age - s.age : num2;
return num3;
}
}
import java.util.TreeSet;
/**
* 需求：请按照姓名的长度排序
* @author wym
*
*/
public classTreeSetDemo {
public static void main(String[] args) {
// TODO Auto-generated method stub
// 创建集合对象
TreeSet<Student>ts = newTreeSet<Student>();
// 创建元素
Students1 = newStudent("linqingxia", 27);
Students2 = newStudent("zhangguorong", 29);
Students3 = newStudent("wanglihong", 23);
Students4 = newStudent("linqingxia", 27);
Students5 = newStudent("liushishi", 22);
Students6 = newStudent("wuqilong", 40);
Students7 = newStudent("fengqingy", 22);
Students8 = new Student("linqingxia",29);
// 添加元素
ts.add(s1);
ts.add(s2);
ts.add(s3);
ts.add(s4);
ts.add(s5);
ts.add(s6);
ts.add(s7);
ts.add(s8);
// 遍历
for (Student s : ts) {
System.out.println(s.getName() + "---" + s.getAge());
}
}
}
运行结果：
wuqilong---40
fengqingy---22
liushishi---22
linqingxia---27
linqingxia---29
wanglihong---23
zhangguorong---29