package testExample;

import org.junit.Test;

import java.util.*;

public class RC4 {

    @Test

    public  void  RC4(){

        List<String> list = new ArrayList<>();

        Set<String> set = new HashSet<>();

        System.out.println(System.currentTimeMillis());

        for(int i = 0 ; i < 1000000; i++){

            String uuid = UUID.randomUUID().toString().replace("-","").toUpperCase().substring(0,16);

            String ss = RC42hex02(HloveyRC4(uuid,"angelSXD"));

            list.add(ss);

            set.add(ss);

        }

        System.out.println("list长度："+list.size());

        System.out.println("set长度："+set.size());

        System.out.println(System.currentTimeMillis());

    }

    public static String RC42hex02(String str){

        final String HEX = "0123456789abcdef";

        StringBuffer stringBuffer = new StringBuffer();

        byte [] bytArr = str.getBytes();

        for (byte b : bytArr) {

            // 取出这个字节的高4位，然后与0x0f与运算，得到一个0-15之间的数据，通过HEX.charAt(0-15)即为16进制数

            stringBuffer.append(HEX.charAt((b >> 4) & 0x0f));

            // 取出这个字节的低位，与0x0f与运算，得到一个0-15之间的数据，通过HEX.charAt(0-15)即为16进制数

            stringBuffer.append(HEX.charAt(b & 0x0f));

        }

        return stringBuffer.toString();

    }

    public static String HloveyRC4(String aInput,String aKey)

    {

        int[] iS = new int[256];

        byte[] iK = new byte[256];

        for (int i=0;i<256;i++)

            iS[i]=i;

        int j = 1;

        for (short i= 0;i<256;i++)

        {

            iK[i]=(byte)aKey.charAt((i % aKey.length()));

        }

        j=0;

        for (int i=0;i<255;i++)

        {

            j=(j+iS[i]+iK[i]) % 256;

            int temp = iS[i];

            iS[i]=iS[j];

            iS[j]=temp;

        }

        int i=0;

        j=0;

        char[] iInputChar = aInput.toCharArray();

        char[] iOutputChar = new char[iInputChar.length];

        for(short x = 0;x<iInputChar.length;x++)

        {

            i = (i+1) % 256;

            j = (j+iS[i]) % 256;

            int temp = iS[i];

            iS[i]=iS[j];

            iS[j]=temp;

            int t = (iS[i]+(iS[j] % 256)) % 256;

            int iY = iS[t];

            char iCY = (char)iY;

            iOutputChar[x] =(char)( iInputChar[x] ^ iCY) ;

        }

        return new String(iOutputChar);

    }

}