Collections.sort简单运用

package test1_6_13_2019;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

public class StringsortDemo {

public static void main(String[] args) {
	ArrayList<String> list = new ArrayList<String>();
	list.add("dsdsadsa");
	list.add("ds");
	list.add("da");
	list.add("skkjkhkhj");
	//此处如果输入的字符串长度相同的时候系统会按照字符串的add顺序打印
	Collections.sort(list, new MyComparator());
	System.out.println(list);
}

}

class MyComparator implements Comparator {

public int compare(String o1, String o2) {
//此处如果为o1.length()-o2.length()则为按长度从小到大排序
//此处为从大到小排序。
		return o2.length() - o1.length();
}

}