1 public class Person implements Comparable{
2 private String name;
3 private int age;
4
5 public Person(){
6 super();
7 }
8 public Person(String name, int age)
9 {
10 super();
11 this.name = name;
12 this.age = age;
13 }
14
15
16 @Override
17 public int hashCode() {
18
19 return name.hashCode()+age*27;
20 }
21 @Override
22 public boolean equals(Object obj) {
23 if (this == obj)
24 return true;
25 if (!(obj instanceof Person))
26 throw new ClassCastException("類型錯誤");
27
28 Person p = (Person) obj;
29
30 return this.name.equals(p.name) && this.age == p.age;
31 }
32 @Override
33 public String toString() {
34
35 return name+":"+age;
36 }
37 public String getName() {
38 return name;
39 }
40 public void setName(String name) {
41 this.name = name;
42 }
43 public int getAge() {
44 return age;
45 }
46 public void setAge(int age) {
47 this.age = age;
48 }
49 @Override
50 public int compareTo(Object o) { //先按年齡排，再按姓名排
51
52 Person p = (Person)o;
53
54 int temp = this.age - p.age;
55
56 return temp==0? this.name.compareTo(p.name):temp;
57
58
59 }
60
61
62 }
1 import java.util.Comparator;
2
3 import cn.itcast.p1.bean.Person;
4
5 public class ComparatorByName implements Comparator { //先按姓名排，再按年齡排
6
7 @Override
8 public int compare(Object o1, Object o2) {
9 Person p1 = (Person)o1;
10 Person p2 = (Person)o2;
11
12 int temp = p1.getName().compareTo(p2.getName());
13
14 return temp==0?p1.getAge()-p2.getAge() : temp;
15 }
16
17 }
1 import java.util.Iterator;
2 import java.util.TreeSet;
3
4 import cn.itcast.p1.bean.Person;
5 import cn.itcast.p5.comparator.ComparatorByName;
6
7 public class TreeSetDemo {
8
9 public static void main(String[] args) {
10 // demo1();
11 TreeSet ts = new TreeSet(new ComparatorByName()); //添加 new ComparatorByName（），會出現結果一，去除的話 ，出現結果2
//Comparator 優先於 Comparable
12
13 ts.add(new Person("zhangsan",28));
14 ts.add(new Person("lisi",21));
15 ts.add(new Person("zhouqi",29));
16 ts.add(new Person("zhaoliu",25));
17 ts.add(new Person("wangwu",24));
18 ts.add(new Person("lisi",21));
19 ts.add(new Person("zhouqi",29));
20
21 Iterator it = ts.iterator();
22
23 while (it.hasNext())
24 {
25 Person p = (Person)it.next();
26
27 System.out.println(p);
28 }
29
30 }
31
32 public static void demo1() {
33 TreeSet ts = new TreeSet();
34
35 ts.add("abc");
36 ts.add("zaa");
37 ts.add("aa");
38 ts.add("nba");
39 ts.add("cba");
40
41 Iterator it = ts.iterator();
42
43 while (it.hasNext())
44 {
45 System.out.println(it.next());
46 }
47 }
48
49 }
