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pack

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。

java PHP pack unpack