java decoding hexadecimal ascii code , has the code , seeking to correct

  public static String DecodeASCII(String ascii){
  	ArrayList<Byte> buffer =new ArrayList<Byte>();
      for (int i = 0; i < ascii.length(); i += 2)
      {
          String temp = ascii.substring(i, 2);
          byte value = Convert.ToByte(temp, 16);
          buffer.add(value);
      }
     String str =  System.Text.Encoding.ASCII.GetString(buffer.toArray());
  }
  

This is the C # approach to java inside there is an error after the following two
byte value = Convert.ToByte (temp, 16); Error : Convert cannot be resolved
String str = System.Text.Encoding.ASCII.GetString (buffer.toArray ()); Error : Text cannot be resolved or is not a field

seeking solutions
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java and C # can not be directly copied and used ... Convert object System.Text not exist.
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good , thank 2nd floor , I found a way , by the way posted up !
/ / will be decoded into a string of hexadecimal digits for all characters ( including Chinese )


public static String decode (String bytes)
{
ByteArrayOutputStream baos = new ByteArrayOutputStream (bytes.length () / 2);
/ / each two hexadecimal integer assembled into a byte
String hexString = "0123456789ABCDEF";
for (int i = 0; i baos.write ((hexString.indexOf (bytes.charAt (i)) << 4 | hexString.indexOf (bytes.charAt (i +1))));
return new String (baos.toByteArray ());
}
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gives you two ways :

  /**  
  	  * 将byte数组转换为表示16进制值的字符串， 如：byte[]{8,18}转换为：0813， 和public static byte[]  
  	  * hexStr2ByteArr(String strIn) 互为可逆的转换过程  
  	  *   
  	  * @param arrB  
  	  *            需要转换的byte数组  
  	  * @return 转换后的字符串  
  	  * @throws Exception  
  	  *             本方法不处理任何异常，所有异常全部抛出  
  	  */  
  	public static String byteArr2HexStr(byte[] arrB) throws Exception {
  		int iLen = arrB.length;
  		// 每个byte用两个字符才能表示，所以字符串的长度是数组长度的两倍
  		StringBuffer sb = new StringBuffer(iLen * 2);
  		for (int i = 0; i < iLen; i++) {
  			int intTmp = arrB[i];
  			// 把负数转换为正数
  			while (intTmp < 0) {
  				intTmp = intTmp + 256;
  			}
  			// 小于0F的数需要在前面补0
  			if (intTmp < 16) {
  				sb.append("0");
  			}
  			sb.append(Integer.toString(intTmp, 16));
  		}
  		return sb.toString();
  	}
  
  	/**
  	 * 将表示16进制值的字符串转换为byte数组， 和public static String byteArr2HexStr(byte[] arrB)
  	 * 互为可逆的转换过程
  	 * 
  	 * @param strIn
  	 *            需要转换的字符串
  	 * @return 转换后的byte数组
  	 * @throws Exception
  	 *             本方法不处理任何异常，所有异常全部抛出
  	 */
  	public static byte[] hexStr2ByteArr(String strIn) throws Exception {
  		byte[] arrB = strIn.getBytes();
  		int iLen = arrB.length;
  
  		// 两个字符表示一个字节，所以字节数组长度是字符串长度除以2
  		byte[] arrOut = new byte[iLen / 2];
  		for (int i = 0; i < iLen; i = i + 2) {
  			String strTmp = new String(arrB, i, 2);
  			arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
  		}
  		return arrOut;
  	}
  
  

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No, what I mean is :
now got a String: 6162637A3132333435363738
I how can this hex ascii code to restore to a string : abcd12345678

you this is a string and byte [] array conversion between. I approach the third floor , time-tested , it is recommended that you use
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Oh , I actually see the C # code , LZ code helpful to me .
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well be useful to me .