【原创】Java中Byte字节流处理的自定义方法库1

1.将不同的byte[]字节数组流打包成一个字节数组
 public static byte[] pack(byte[]... agrs) {
     ByteArrayOutputStream bout = new ByteArrayOutputStream();
     for(byte[] b:agrs){
      if(b!=null){
       try {
     bout.write(b);
    } catch (IOException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
      }
      continue;
     }
     byte[] buff = bout.toByteArray();
     return buff;
 }

2.在byte字节流中搜索指定字节流的位置，采用KMP算法实现。
    /**取到字节流中指定字节流的位置
     * The Knuth-Morris-Pratt Pattern Matching Algorithm can be used to search a byte array.
     * Search the data byte array for the first occurrence
     * of the byte array pattern.
     */
 public static int indexOf(byte[] data, byte[] pattern) {
        int[] failure = computeFailure(pattern);
        int j = 0;
        for (int i = 0; i < data.length; i++) {
            while (j > 0 && pattern[j] != data[i]) {
                j = failure[j - 1];
            }
            if (pattern[j] == data[i]) {
                j++;
            }
            if (j == pattern.length) {
             return i + 1;
             //return i - pattern.length + 1;
            }
        }
        return -1;
    }

     /**
     * Computes the failure function using a boot-strapping process,
     * where the pattern is matched against itself.
     */
    private static int[] computeFailure(byte[] pattern) {
        int[] failure = new int[pattern.length];
        int j = 0;
        for (int i = 1; i < pattern.length; i++) {
            while (j>0 && pattern[j] != pattern[i]) {
                j = failure[j - 1];
            }
            if (pattern[j] == pattern[i]) {
                j++;
            }
            failure[i] = j;
        }
        return failure;
    }

3.将字节流的详细信息显示
 //HEX字节流显示
 public static String dumpBytesAsHEX(byte[] bytes) {
  int idx = 0;
  String s = "";
  StringBuilder body = new StringBuilder();
  for (int i=0;i<1024&&i<bytes.length;i++) {
   byte b = bytes[i];
   int hex = ((int) b) & 0xff;
   String shex = Integer.toHexString(hex).toUpperCase();
   if (1 == shex.length()) {
    body.append("0");
   }
   body.append(shex);
   body.append(" ");
   idx++;
//   if (16 == idx) {
//    s = body.toString();
//    body = new StringBuilder();
//    idx = 0;
//   }
  }
  if (idx != 0) {
   s = body.toString();
  }
  return s;
 }