java collection 学习一

参考：原文地址

1.java collection overview

2.Map 接口 概览

3、常用接口方法使用示例

package com.interview.base.collection;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

public class MyCollectionUtil {
     public static void doSomething(Collection collection) {
            
            Iterator iterator = collection.iterator();
            while(iterator.hasNext()){
              Object object = iterator.next();

              //do something to object here...
            }
          }
     public static void main(String[] args) {
        
         String     anElement  = "an element";
         String     twoElement  = "an element";
         Collection setCollection = new HashSet();
         Collection listCollection = new ArrayList();
         
         boolean setChange = setCollection.add(anElement);
         boolean setChange2 = setCollection.add(anElement);
         System.out.println(setChange2);
         
         System.out.println("setCollection: "+ setCollection.size());
         
         System.out.println("contain test: " + setCollection.contains("aobo"));
         
         boolean  removeExist = setCollection.remove(anElement);
         boolean  removeNotExist = setCollection.remove("aobo");
         
         System.out.println("removeExist: " + removeExist);
         
         System.out.println("removeNotExist: " + removeNotExist);

         boolean listChange = listCollection.add(anElement);
         boolean listChange2 = listCollection.add(anElement);
         
         System.out.println("listCollection: "+ listCollection.size());
         
         
         // the first output method
         for(Object s : listCollection){
             System.out.println(s.toString());
         }
         
         //the secondn output  method
         Iterator iterator = listCollection.iterator();
         
         System.out.println("----------------------华丽分割线---------------------------------");
         while(iterator.hasNext()){
                Object object = iterator.next();
                //do something to object;    
                System.out.println(object.toString());
            }
    }
}

Collection下集合包含有以下接口

• List
• Set
• SortedSet
• NavigableSet
• Queue
• Deque