[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;
}

@Override
public 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;
}

@Override
public int hashCode() {
return this.name.hashCode() * this.age;
}

@Override
public 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);
}
}