java RC4加密解密

    package com.*;  
      
    public class RC4 {  
      
        public static String decry_RC4(byte[] data,String key) {  
            if (data == null || key == null) {  
                return null;  
            }  
            return asString(RC4Base(data,key));  
        }  
      
        public static String decry_RC4(String data,String key) {  
            if (data == null || key == null) {  
                return null;  
            }  
            return new String(RC4Base(HexString2Bytes(data),key));  
        }  
      
        public static byte[] encry_RC4_byte(String data,String key) {  
            if (data == null || key == null) {  
                return null;  
            }  
            byte b_data[] = data.getBytes();  
            return RC4Base(b_data,key);  
        }  
      
        public static String encry_RC4_string(String data,String key) {  
            if (data == null || key == null) {  
                return null;  
            }  
            return toHexString(asString(encry_RC4_byte(data,key)));  
        }  
      
        private static String asString(byte[] buf) {  
            StringBuffer strbuf = new StringBuffer(buf.length);  
            for (int i = 0; i < buf.length; i++) {  
                strbuf.append((char) buf[i]);  
            }  
            return strbuf.toString();  
        }  
      
        private static byte[] initKey(String aKey) {  
            byte[] b_key = aKey.getBytes();  
            byte state[] = new byte[256];  
      
            for (int i = 0; i < 256; i++) {  
                state[i] = (byte) i;  
            }  
            int index1 = 0;  
            int index2 = 0;  
            if (b_key == null || b_key.length == 0) {  
                return null;  
            }  
            for (int i = 0; i < 256; i++) {  
                index2 = ((b_key[index1] & 0xff) + (state[i] & 0xff) + index2) & 0xff;  
                byte tmp = state[i];  
                state[i] = state[index2];  
                state[index2] = tmp;  
                index1 = (index1 + 1) % b_key.length;  
            }  
            return state;  
        }  
      
        private static String toHexString(String s) {  
            String str = "";  
            for (int i = 0; i < s.length(); i++) {  
                int ch = (int) s.charAt(i);  
                String s4 = Integer.toHexString(ch & 0xFF);  
                if (s4.length() == 1) {  
                    s4 = '0' + s4;  
                }  
                str = str + s4;  
            }  
            return str;// 0x表示十六进制  
        }  
      
        private static byte[] HexString2Bytes(String src) {  
            int size = src.length();  
            byte[] ret = new byte[size / 2];  
            byte[] tmp = src.getBytes();  
            for (int i = 0; i < size / 2; i++) {  
                ret[i] = uniteBytes(tmp[i * 2],tmp[i * 2 + 1]);  
            }  
            return ret;  
        }  
      
        private static byte uniteBytes(byte src0,byte src1) {  
            char _b0 = (char) Byte.decode("0x" + new String(new byte[] { src0 })).byteValue();  
            _b0 = (char) (_b0 << 4);  
            char _b1 = (char) Byte.decode("0x" + new String(new byte[] { src1 })).byteValue();  
            byte ret = (byte) (_b0 ^ _b1);  
            return ret;  
        }  
      
        private static byte[] RC4Base(byte[] input,String mKkey) {  
            int x = 0;  
            int y = 0;  
            byte key[] = initKey(mKkey);  
            int xorIndex;  
            byte[] result = new byte[input.length];  
      
            for (int i = 0; i < input.length; i++) {  
                x = (x + 1) & 0xff;  
                y = ((key[x] & 0xff) + y) & 0xff;  
                byte tmp = key[x];  
                key[x] = key[y];  
                key[y] = tmp;  
                xorIndex = ((key[x] & 0xff) + (key[y] & 0xff)) & 0xff;  
                result[i] = (byte) (input[i] ^ key[xorIndex]);  
            }  
            return result;  
        }  
      
        public static void main(String[] args) {  
            String inputStr = "做个好男人";  
            String str = encry_RC4_string(inputStr,"123456");  
            System.out.println(str);  
            System.out.println(decry_RC4(str,"123456"));  
        }  
    }