testcollections.java

来自「由浅入深的介绍JAVAse的基本编程思想」· Java 代码 · 共 48 行

import java.util.Vector;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;

public class TestCollections{
	public static void main(String[] args) {
		ArrayList alist = new ArrayList();
		alist.add(75); 
		alist.add(38); 
		alist.add(21); 
		alist.add(4); 
		alist.add(12); 

		System.out.println("原列表: " + alist);
		Collections.sort(alist);
		System.out.println("排序后: " + alist);
		Collections.reverse(alist);
		System.out.println("逆序后: " + alist);
		Collections.shuffle(alist);
		System.out.println("混排后: " + alist);
		Collections.rotate(alist,2);
		System.out.println("移位后: " + alist);		
		
		ArrayList blist = new ArrayList();
		blist.add(55); 
		blist.add(66);
		System.out.println("新列表: " + blist);
		Collections.copy(alist,blist);
		System.out.println("拷贝后: " + alist);

		System.out.println("列表中出现元素66的次数: " + Collections.frequency(alist,66));
		System.out.println("列表中元素的最大值: " + Collections.max(alist));
		System.out.println("列表中元素的最小值: " + Collections.min(alist));

		Enumeration en = createDemoEnumeration();
		ArrayList clist = Collections.list(en);
		System.out.println("Enumeration->ArrayList: " + alist);
	}
	
	public static Enumeration createDemoEnumeration(){
		Vector v = new Vector();
		v.add("Tom");		
		v.add("Billy");		
		v.add("Jenny");		
		return v.elements();	
	}
}