Android-RC4的加密解密代码

static String RC4(String keys, String encrypt) {
        char[] keyBytes = new char[256];
        char[] cypherBytes = new char[256];
 
        for (int i = 0; i < 256; ++i) {
            keyBytes[i] = keys.charAt(i % keys.length());
            cypherBytes[i] = (char) i;
        }
 
        int jump = 0;
        for (int i = 0; i < 256; ++i) {
            jump = (jump + cypherBytes[i] + keyBytes[i]) & 0xFF;
            char tmp = cypherBytes[i]; // Swap:
            cypherBytes[i] = cypherBytes[jump];
            cypherBytes[jump] = tmp;
        }
 
        int i = 0;
        jump = 0;
        String Result = "";
        for (int x = 0; x < encrypt.length(); ++x) {
            i = (i + 1) & 0xFF;
            char tmp = cypherBytes[i];
            jump = (jump + tmp) & 0xFF;
            char t = (char) ((tmp + cypherBytes[jump]) & 0xFF);
            cypherBytes[i] = cypherBytes[jump]; // Swap:
            cypherBytes[jump] = tmp;
 
            try {
                Result += new String(new char[] { (char) (encrypt.charAt(x) ^ cypherBytes[t]) });
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
 
        return Result;
    }