/*

* Copyright 2012-2013 The Haohui Network Corporation

*/

package com.haohui.common.utils;

/**

* Java Native和Ascii转换代码

*

* @project common-utils

* @author cevencheng

* @create 2012-11-7 下午4:16:57

*/

public class Native2AsciiUtils {

/**

* prefix of ascii string of native character

*/

private static String PREFIX = "\\u";

/**

* Native to ascii string. It's same as execut native2ascii.exe.

*

* @param str

* native string

* @return ascii string

*/

public static String native2Ascii(String str) {

char[] chars = str.toCharArray();

StringBuilder sb = new StringBuilder();

for (int i = 0; i < chars.length; i++) {

sb.append(char2Ascii(chars[i]));

}

return sb.toString();

}

/**

* Native character to ascii string.

*

* @param c

* native character

* @return ascii string

*/

private static String char2Ascii(char c) {

if (c > 255) {

StringBuilder sb = new StringBuilder();

sb.append(PREFIX);

int code = (c >> 8);

String tmp = Integer.toHexString(code);

if (tmp.length() == 1) {

sb.append("0");

}

sb.append(tmp);

code = (c & 0xFF);

tmp = Integer.toHexString(code);

if (tmp.length() == 1) {

sb.append("0");

}

sb.append(tmp);

return sb.toString();

} else {

return Character.toString(c);

}

}

/**

* Ascii to native string. It's same as execut native2ascii.exe -reverse.

*

* @param str

* ascii string

* @return native string

*/

public static String ascii2Native(String str) {

StringBuilder sb = new StringBuilder();

int begin = 0;

int index = str.indexOf(PREFIX);

while (index != -1) {

sb.append(str.substring(begin, index));

sb.append(ascii2Char(str.substring(index, index + 6)));

begin = index + 6;

index = str.indexOf(PREFIX, begin);

}

sb.append(str.substring(begin));

return sb.toString();

}

/**

* Ascii to native character.

*

* @param str

* ascii string

* @return native character

*/

private static char ascii2Char(String str) {

if (str.length() != 6) {

throw new IllegalArgumentException("Ascii string of a native character must be 6 character.");

}

if (!PREFIX.equals(str.substring(0, 2))) {

throw new IllegalArgumentException("Ascii string of a native character must start with \"\\u\".");

}

String tmp = str.substring(2, 4);

int code = Integer.parseInt(tmp, 16) << 8;

tmp = str.substring(4, 6);

code += Integer.parseInt(tmp, 16);

return (char) code;

}

}