[Java 13 类集合] BasicContainer， Collection, Set, HashSet, TreeSet

package com.qunar.basicJava.javase.p13_ClassCollection;import java.util.Collection; /** 存放单值的最大父接口 */
import java.util.HashSet;/*** Author: libin.chen@qunar.com  Date: 14-6-9 15:58*/
public class BasicContainer {public static void main(String[] args) {Collection c = new HashSet();c.add("hello");c.add(new Name("f1", "l1"));c.add(new Integer(100));c.remove("hello");c.remove(new Integer(100));System.out.println(c.remove(new Name("f1", "l1")));System.out.println(c);}
}class Name implements Comparable {private String firstName, lastName;public Name(String firstName, String lastName) {this.firstName = firstName;this.lastName = lastName;}public String getFirstName() {return firstName;}public String getLastName() {return lastName;}public String toString() {return firstName + " " + lastName;}public boolean equals(Object obj) {if (obj instanceof Name) {Name name = (Name) obj;return (firstName.equals(name.firstName))&& (lastName.equals(name.lastName));}return super.equals(obj);}public int hashCode() {return firstName.hashCode(); // 重写 equals 方法必须要重写 hashCode 方法， 当你 Name 类这个对象作为索引,key的时候，就要用到 hashCode}public int compareTo(Object o) {Name n = (Name) o;int lastCmp = lastName.compareTo(n.lastName); // 调用 String 的 compareTo 方法return (lastCmp != 0 ? lastCmp : firstName.compareTo(n.firstName));}}

package com.qunar.basicJava.javase.p13_ClassCollection;import java.util.HashSet;
import java.util.Set;/*** Author: libin.chen@qunar.com  Date: 14-6-9 19:30** HashSet 知识点， 采用散列的存储方式，所有没有顺序，直接 println(HashSet) : 调用的 toString()*/
public class HashSetDemo01 {public static void main(String[] args) {Set<String> strings = new HashSet<>();strings.add("A");strings.add("B");strings.add("C");strings.add("D");System.out.println(strings); //}
}
/*** 输出 ：* [D, A, B, C]*/

package com.qunar.basicJava.javase.p13_ClassCollection;import java.util.Set;
import java.util.TreeSet;/*** Author: libin.chen@qunar.com  Date: 14-6-9 19:43** TreeSet 有序，extends AbstractSet<E> implements SortedSet<E>, Serializable*/
public class TreeSetDemo01 {public static void main(String[] args) {Set<String> strings = new TreeSet<String>();strings.add("C");strings.add("A");strings.add("B");System.out.println(strings);}
}
/** 输出 ：[A, B, C]*/

package com.qunar.basicJava.javase.p13_ClassCollection;/*** Author: libin.chen@qunar.com  Date: 14-6-9 20:45*/
class Person {private String name;private int age;public Person(String name, int age) {this.name = name;this.age = age;}@Overridepublic boolean equals(Object obj) {if (this == obj) return true;if (!(obj instanceof Person)) {return false;}Person person = (Person) obj;if (this.name.equals(person.name) && this.age == person.age) {return true;} else return false;}@Overridepublic int hashCode() {return this.name.hashCode() * this.age;}@Overridepublic String toString() {return "姓名 : " + this.name + " 年龄 : " + this.age;}
}

package com.qunar.basicJava.javase.p13_ClassCollection;import java.util.HashSet;
import java.util.Set;/*** Author: libin.chen@qunar.com  Date: 14-6-9 20:51*/
public class RepeatDemo {public static void main(String[] args) {Set<Person> persons = new HashSet<>();persons.add(new Person("张3", 30));persons.add(new Person("张4", 28));persons.add(new Person("张5", 30));persons.add(new Person("张4", 28));persons.add(new Person("张7", 30));System.out.println(persons);}
}

输出 ：

[姓名 : 张3 年龄 : 30, 姓名 : 张7 年龄 : 30, 姓名 : 张4 年龄 : 28, 姓名 : 张5 年龄 : 30]