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{     /**     * 打包字符串     * 类似php中pack在java中的实现     *     * @param str     * @return     */    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;    }     /**     * 16进制的字符解压 类php中unpack     *     * @param is     * @param len     * @return     * @throws IOException     */    public static String unpack(InputStream is, int len) throws IOException {      byte[] bytes = new byte[len];      is.read(bytes);      return unpack(bytes);    }     /***     * 16进制的字符解压 类php中unpack     * @param bytes     * @return     */    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。