java实现图形滑块验证码

package com.xtech.hello.server.user.NECcode.old;

import com.xtech.hello.server.common.enums.BackgroundTypeEnum;
import org.springframework.core.io.ClassPathResource;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
 * @name 
 * 背景资源
 */
public class BackgroundUtils {

    private static final   List<ClassPathResource> backgroundBigList = new ArrayList<>();

    private static  final  List<ClassPathResource> backgroundSmallList = new ArrayList<>();

    static {
        for (int i = 0; i < 10; i++) {
            ClassPathResource classPathResourceBig = new ClassPathResource("backgroundImg/big/" + i + ".jpg");
            ClassPathResource classPathResourceSmall = new ClassPathResource("backgroundImg/small/" + i + ".jpg");
            if (classPathResourceBig.exists()) {
                    backgroundBigList.add(classPathResourceBig);
            }
            if(classPathResourceSmall.exists()){
                    backgroundSmallList.add(classPathResourceSmall);
            }
        }
    }

    public static List<ClassPathResource> getBackgroundResource(BackgroundTypeEnum type){
        if(type==BackgroundTypeEnum.SMALL){
            return backgroundSmallList;
        }else{
            return backgroundBigList;
        }
    }

    public static int getRandomNumber(int lowerbound, i