how to get the tag value from the string

In php you can use this script

function get_string($string, $start, $end){
    $string = ' ' . $string;
    $ini = strpos($string, $start);
    if ($ini == 0) return '';
    $ini += strlen($start);
    $len = strpos($string, $end, $ini) - $ini;
    return substr($string, $ini, $len);
}

Hi CEHJ,

Is there any other apporach.
it is taking 17 milliseconds time to get the value.

this operation i am doing on huge data.

I wish you'd said that earlier. Use an xml pull parser
https://en.wikipedia.org/wiki/StAX

If speed is a concern and message always start like this:
<notify:Header><notify:uuid>
then I would update dpearson's code like this:

private String getField(String msg) {
		string result="";
               int i=28; 
               while(msg[i]!='<')
                             result+=msg[i];
	      return result;
	}
	String uuid = getField(msg);

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then I would update dpearson's code like this:

No - string concatenation should be avoided - it's inefficient. If you don't know why, decompile the code that is produced by it and look how StringBuilder/StringBuffer works in Java

Of course, this question begs other, such as: why is an xml document, which is apparently massive, being held in memory (in a String) in the first place if the use case is to obtain one value from it?

Hi CEHJ,

xml file I am recieving from the MQ queue,after recieving from the queue converting it as String.
From this i need only one tag value.

thanks

:)

xml file I am recieving from the MQ queue,after recieving from the queue converting it as String.

There might be a better way of doing that

You only needed to splice out the id, like this :

System.out.println(msg.substring(msg.indexOf("d>")+2,msg.indexOf("</")));

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(100,000 iterations of that (without the System.println() obviously), took 31 ms on my machine).

getField(String msg) takes less then 1ms to execute.
while this: msg = msg.replaceAll(".*<notify:uuid>(.*?)</notify:uuid>.*", "$1");
takes 13 ms.

here is the test code:

class test{
    public static String getField(String msg) {               
       int i=28;      
       char[]  msgArray = msg.toCharArray();       
       String result ="";
       while(msgArray[i]!='<')
       {             
        result+=msgArray[i];                             
        i++;
       }
         
         return result;
         
   }
    public static void main(String[] args) {
      long startTime = System.nanoTime();
       String msg = "<notify:Header><notify:uuid>c364a2143e1f4fb58a87b1530c5007cd</notify:uuid><notify:SystemCode>DTP</notify:SystemCode><notify:countryCode>AE</notify:countryCode><notify:Identifier>SYSTEM</notify:Identifier></notify:Header>";    
       msg = msg.replaceAll(".*<notify:uuid>(.*?)</notify:uuid>.*", "$1");
       //String uuid = getField(msg);   
       System.out.println(msg);
      // System.out.println(uuid);
       long endTime = System.nanoTime(); 
       System.out.println("Took "+(endTime-startTime)/1000000+" ms to run.");
   }
   
   }

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Just in case there's any doubt, my code is not supplied as optimal resource/efficiency - wise (since i was not aware that the input was large). It was supplied for its ease of use

getField(String msg) takes less then 1ms to execute.
while this: msg = msg.replaceAll(".*<notify:uuid>(.*?)</notify:uuid>.*", "$1");
takes 13 ms.

We know all about that. That’s why CEHJ and Doug spoke about it already.