Java List集合中元素比较大小

List<Shoes> all_shoes = new ArrayList<Shoes>();
Collections.sort(all_shoes, new Comparator<Shoes>(){
    @Override
    /* *
     * int compare(String o1, String o2) 返回一个基本类型的整型
     * 返回-1表示：shoes1.getSimilarity()大于等于shoes2.getSimilarity()，
     * 返回1表示：shoes1.getSimilarity()小于shoes2.getSimilarity()，              
     * */
    public int compare(Shoes shoes1, Shoes shoes2) {
        if (shoes1.getSimilarity()<shoes2.getSimilarity()){
            return 1;
        }else{
            return -1;
        }
    }
});
System.out.println("比较后");
for(Shoes s:all_shoes) {
    System.out.println(s.getId());
    System.out.println(s.getShoes_name());
    System.out.println(s.getPrice());
    System.out.println(s.getDeal());
    System.out.println(s.getImage());
    System.out.println(s.getShop_name());
    System.out.println(s.getAddress());
    System.out.println(s.getUrl());
    System.out.println(s.getSource());
    System.out.println(s.getSimilarity());
    System.out.println("--------------------------");
}

package dao;

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

/**
*@author chenmeiqi
*@version 2020年2月24日 下午12:13:17
*/
public class test1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        List<String> keyList = new ArrayList<>();
        keyList.add("abc");
        keyList.add("fgh");
        keyList.add("cvb");
        System.out.println("排序前:");
        for(String s:keyList) {
            System.out.println(s);
        }
        
        Collections.sort(keyList, new Comparator<String>(){
            @Override
            public int compare(String o1, String o2) {
                /*
                 * * int compare(String o1, String o2) 返回一个基本类型的整型，
                 * * 返回负数表示：o1 小于o2，
                 * * 返回0 表示：o1和o2相等，
                 * * 返回正数表示：o1大于o2
                 * */
                if (o1.compareTo(o2) > 0){
                    return 1;
                }else if (o1.compareTo(o2) > 0){
                    return 0;
                }else{
                    return -1;
                }
            }
        });
        System.out.println("排序后:");
        for(String s:keyList) {
            System.out.println(s);
        }

    }

}