Java Collections工具类
package myutil;import java.util.ArrayList;import java.util.Collections;import java.util.Random;public class Collections1 {public static void main(String[] args){ArrayList<Integer> nums=new ArrayList<Integer>();Random random=new Random(System.currentTimeMillis());for(int i=0;i<10;i++)nums.add(random.nextInt(100));System.out.println("original:\n"+nums);Collections.reverse(nums);System.out.println("reverse:\n"+nums);Collections.sort(nums);System.out.println("sort:\n"+nums);Collections.shuffle(nums);System.out.println("shuffle:\n"+nums);System.out.println("max:\n"+Collections.max(nums));System.out.println("min:\n"+Collections.min(nums));System.out.println("frequency of "+nums.get(0)+":\n"+Collections.frequency(nums, nums.get(0)));System.out.println("binarySearch of "+nums.get(4)+":\n"+Collections.binarySearch(nums, nums.get(4)));int orginal=nums.get(2);Collections.replaceAll(nums, orginal, 88);System.out.println("replaceAll of "+orginal+" to value 88:\n"+nums);}}