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。