java模拟PHP的pack和unpack类

本文实例为大家分享了java模拟PHP的pack和unpack类的具体代码，供大家参考，具体内容如下

package qghl.intp.util;
 
import java.io.IOException;
import java.io.InputStream;
 
public class PackUtil{
 
    
    public static byte[] pack(String str) {
      int nibbleshift = 4;
      int position = 0;
      int len = str.length() / 2 + str.length() % 2;
      byte[] output = new byte[len];
      for (char v : str.toCharArray()) {
 byte n = (byte) v;
 if (n >= '0' && n <= '9') {
   n -= '0';
 } else if (n >= 'A' && n <= 'F') {
   n -= ('A' - 10);
 } else if (n >= 'a' && n <= 'f') {
   n -= ('a' - 10);
 } else {
   continue;
 }
 output[position] |= (n << nibbleshift);
 
 if (nibbleshift == 0) {
   position++;
 }
 nibbleshift = (nibbleshift + 4) & 7;
      }
 
      return output;
    }
 
    
    public static String unpack(InputStream is, int len) throws IOException {
      byte[] bytes = new byte[len];
      is.read(bytes);
      return unpack(bytes);
    }
 
    
    public static String unpack(byte[] bytes) {
      StringBuilder stringBuilder = new StringBuilder("");
      if (bytes == null || bytes.length <= 0) {
 return null;
      }
      for (int i = 0; i < bytes.length; i++) {
 int v = bytes[i] & 0xFF;
 String hv = Integer.toHexString(v);
 if (hv.length() < 2) {
   stringBuilder.append(0);
 }
 stringBuilder.append(hv);
      }
      return stringBuilder.toString();
    }
  }

以上就是本文的全部内容，希望对大家学习java程序设计有所帮助。