String Spilt

Hi ,
I have a prob,

I have a string variable with the follorwing data inside it :

49 16:19:19.868042 TCP 2567 > 139 [ACK] Seq=126 Ack=33543 Win=64240 Len=0  tcp.analysis.acks_frame == 45  ip.dst ==  ip.src ==  frame.time == "Apr 25, 2004 16:19:19.86804200"

I want to search the string variable and get the value between the "ip.src == "
and a white space.

I wrote the following code.
BufferedReader in = new BufferedReader(new FileReader(fileName));

while ((bufferinput2 = in.readLine()) != null)
// Check Source IP
sourceipStart = bufferinput2.indexOf("ip.src == ") + 11;
sourceipEnd = bufferinput2.lastIndexOf("  ");
sourceip = bufferinput2.substring(sourceipStart, sourceipEnd);
System.out.println("Source IP : " +sourceip);

But i am not able to search for a white space in the string.Can anybody help me to solve the prob.

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Mayank SAssociate Director - Product EngineeringCommented:
>> sourceipEnd = bufferinput2.lastIndexOf("  ");

- lastIndexOf is not correct. You have to search for the next space after the "ip.src == ". You could try this:

String search = "ip.src == " ;
sourceipStart = bufferinput2.indexOf ( search ) ;
sourceipEnd = bufferinput2.indexOf ( " ", sourceipStart + search.length () ) ;
sourceip = buffer2.substring ( sourceipStart, sourceipEnd ) ;
int sub = bufferinput2.indexOf("ip.src == ");
StringTokenizer st = new StringTokenizer(bufferinput2.substring(sub+10, bufferinput2.length()-1)," ");
    if (st.hasMoreTokens()) {

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tyr this...

/** @return an ArrayList of 2-character Strings. */
   private static ArrayList wordLetterPairs(String str) {
       ArrayList allPairs = new ArrayList();
       // Tokenize the string and put the tokens/words into an array
       String[] words = str.split("s");
       // For each word
       for (int w=0; w < words.length; w++) {
           // Find the pairs of characters
           String[] pairsInWord = letterPairs(words[w]);
           for (int p=0; p < pairsInWord.length; p++) {
       return allPairs;

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>I want to search the string variable and get the value between the "ip.src == " and a white space.

Searching result may be found or not ... so you should test it before get the value

while ((bufferinput2 = in.readLine()) != null) {
    sourceip = "";
    sourceipStart = bufferinput2.indexOf( "ip.src == " );
    if( sourceipStart > -1 ) {
        sourceipEnd = bufferinput2.indexOf ( " ", sourceipStart + 7) ;
        sourceip = buffer2.substring ( sourceipStart, sourceipEnd ) ;
    System.out.println("Source IP : " +sourceip);

G noon
sourceip = buffer2.substring ( sourceipStart, sourceipEnd ) ;

should be

sourceip = bufferinput2.substring ( sourceipStart, sourceipEnd ) ;
You can also use a regular expression:

            String x = "49 16:19:19.868042 TCP 2567 > 139 [ACK] Seq=126 Ack=33543 Win=64240 Len=0  tcp.analysis.acks_frame == 45  ip.dst ==  ip.src ==  frame.time == \"Apr 25, 2004 16:19:19.86804200\"";
            final String RE = ".+ip.src\\s==\\s([0-9\\.]+).+";
            Pattern p = Pattern.compile(RE);
            Matcher m = p.matcher(x);
            if (m.matches()) {
Mayank SAssociate Director - Product EngineeringCommented:
Sri Hari,

Do you know that sometimes it is good to do some thinking and application of programming on your own rather than let somebody give you completely working code. If you had tried my code a little, you would've known that I made a small mistake in:

>> sourceip = buffer2.substring ( sourceipStart, sourceipEnd ) ;

It should be: sourceip = bufferinput2.substring ( sourceipStart + search.length (), sourceipEnd ) ;

If you'd tried fiddling a little with it, you would've come to the solution yourself.

The reason why I don't feel comfortable using a StringTokenizer here is that you want to read only one IP address (only one token) so there's no use creating a new StringTokenizer object and loop through it.

BTW, the regular expression approach is really good for all cases.

Just a word of advice, nothing else. I don't mind which answer gets accepted.

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