Regex expressions

[Angus Ferguson]

Hi,

I need to get only 7212 from a string like this one

12:22:44;7212;HTTP Request;200;Thread Group 1-1333;true;172652;2025;2025;https://www.domain.com/de/mehr/sport;;6020;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;5626

I have tried with the expression

^\A{;}/z$

I try to express it should get after the first

;

till the second

;

I am using https://regex101.com/ it gives some advice about the errors and still I cant solve completely the expression


Any idea, please?

Regards, Isaac

[Stephan van Hulst]

Why not use a Scanner with useDelimiter(";")? Perform next() twice and you're done.

[Stephan van Hulst]

Scanner is almost *always* a better solution than applying regular expressions directly. Take the time to get intimate with its API, because dissecting strings will become much easier.

[Stephan van Hulst]

And just to be a bastard: "Regex expression" is a tautology ;)

[salvin francis]

Are you sure you want to refer to that site assuming that you are writing code in java, pleas refer java's regex documentation.
http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html
I am still unsure about how this can be solved using regex.

[Stephan van Hulst]

Salvin, it can be done using capturing groups. Describe the part of the input you want to capture, and then either see if the input matches(), or find() the next occurrence. Then return the value of the capturing group().

However, Scanner is more elegant.

[Henry Wong]

Regarding the regex itself ...

Isaac Ferguson wrote:I have tried with the expression

^\A{;}/z$

What are you trying to do here? This is not even close to a valid regex. If it was close, we could probably figure out what you are trying to accomplish, and suggest a fix -- but this expression is (with the exception of the first and last character) no where close to a valid regex.

Henry

[salvin francis]

I would definitely recommend Scanner.

But I just wanted to check with regex

Pattern startPattern = Pattern.compile("^(\\d)*:(\\d)*:(\\d)*;");
Pattern endPattern = Pattern.compile("^(\\d)*:(\\d)*:(\\d)*;(\\d)*;");
Matcher matcher1 = startPattern.matcher(str);
Matcher matcher2 = endPattern.matcher(str);
boolean find1 = matcher1.find();
boolean find2 = matcher2.find();

and then do a substring from matcher1.end() to matcher2.end()-1 if both the finds are true ?

[Henry Wong]

salvin francis wrote:
and then do a substring from matcher1.end() to matcher2.end()-1 if both the finds are true ?

You do know that you used the regular expression engine to do ... essentially an "index of" for the first two semicolon characters right? Isn't it much easier to just use the indexOf() method instead?

Henry

[salvin francis]

Henry Wong wrote:
You do know that you used the regular expression engine to do ... essentially an "index of" for the first two semicolon characters right

Yes

Henry Wong wrote:
Isn't it much easier to just use the indexOf()

I agree

Stephan van Hulst wrote:Salvin, it can be done using capturing groups. Describe the part of the input you want to capture, and then either see if the input matches(), or find() the next occurrence. Then return the value of the capturing group().

I was just trying Stephan's proposal actually to see if I was in line with what he meant.

I too said a Scanner is a better choice. I would have simply used a StringTokenizer

[Henry Wong]

salvin francis wrote:

Stephan van Hulst wrote:Salvin, it can be done using capturing groups. Describe the part of the input you want to capture, and then either see if the input matches(), or find() the next occurrence. Then return the value of the capturing group().

I was just trying Stephan's proposal actually to see if I was in line with what he meant.

Stephan was talking about using capturing groups to capture the result. While you have capturing groups in your regex, you are certainly not using them. Instead you are obtaining the result via the substring() call -- and not via capturing group.

Henry

[Stephan van Hulst]

The regex is also concerned with too much information. Why do you need to describe the part that comes before the first semi-colon? You don't care what it looks like, so don't describe it. Use either Matcher.find() with the pattern ";(\\d+);", or use Matcher.matches() with the pattern ".*?;(\\d+);.*".

[Stephan van Hulst]

salvin francis wrote:I too said a Scanner is a better choice. I would have simply used a StringTokenizer

Java™ Platform, Standard Edition 8 API Specification wrote:StringTokenizer is a legacy class that is retained for compatibility reasons although its use is discouraged in new code.

[salvin francis]

Thanks for the info guys, its news to me that string tokenizer is discouraged maybe am not so updated after all.

[Angus Ferguson]

Hi,

I have tried with Scanner like this:

    
       while ((aLine = lineReader.readLine()) != null) {
          
                Scanner sc = new Scanner(aLine).useDelimiter(";");

                System.out.println("" + sc.next());
                System.out.println("" + sc.next());

  

I got from the info web Scanner API

What I need is get from a string like this

12:22:44;7212;HTTP Request;200;Thread Group 1-1333;true;172652;2025;2025;https://www.domain.com/de/mehr/sport;;6020;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;5626

is only the second element in this case 7212

When I debug

sc.next();

it gives me other parts of the string like "HTTP Request" or others depending of the line it is reading from the textFile instead of stay getting every second element corresponding to miliseconds of every line.

Any idea, please?

[Stephan van Hulst]

Well, we can't really help you if we don't know what the inputs are that you're using, what you're expecting to see, and what the actual outputs are.

[salvin francis]

Isaac Ferguson wrote:
it gives me other parts of the string like "HTTP Request"

It will help us help you better if you posted 2-3 lines within that file that your program gives erroneous readings on.

[Angus Ferguson]

I am using new file from a new JMeter test, it looks like this:

timeStamp;elapsed;label;responseCode;threadName;success;bytes;grpThreads;allThreads;URL;Filename;Latency;Encoding;SampleCount;ErrorCount;Hostname;IdleTime;Connect																			
12:41:43;287;HTTP sydney;200;Thread Group 1-10;true;113887;12;12;https://www.domain.com/de/city/sydney;;223;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;84
12:41:43;495;HTTP sydney;200;Thread Group 1-8;true;113887;13;13;https://www.domain.com/de/city/sydney;;418;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;273
12:41:43;672;HTTP sydney;200;Thread Group 1-2;true;113887;13;13;https://www.domain.com/de/city/sydney;;594;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444
12:41:43;676;HTTP sydney;200;Thread Group 1-4;true;113887;13;13;https://www.domain.com/de/city/sydney;;609;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444

The code i am debugging looks like this:

             FileReader fr = new FileReader(file_name);
             BufferedReader lineReader = new BufferedReader(fr);
         
             String aLine;
             int counter=0;

             while ((aLine = lineReader.readLine()) != null){
                
                Scanner sc = new Scanner(aLine).useDelimiter(";");
                System.out.println("" + sc.next());
                System.out.println("" + sc.next());}

In the first iteration I get "12:41:43" and "HTTP sydney" it doesnt gets the value I am looking for "287" and in the second iteration It gets "True" and "13"

Any idea, please?

[Stephan van Hulst]

When I run that exact piece of code against the data you provided, I get precisely the results you want.

package com.example;

import java.io.*;
import java.util.*;

final class Test {

  public static void main(String... args) throws Exception {
    FileReader fr = new FileReader("test.txt");
    BufferedReader lineReader = new BufferedReader(fr);

    String aLine;
    int counter = 0;

    while ((aLine = lineReader.readLine()) != null) {

      Scanner sc = new Scanner(aLine).useDelimiter(";");
      System.out.println("" + sc.next());
      System.out.println("" + sc.next());
    }
  }
}

timeStamp
elapsed
12:41:43
287
12:41:43
495
12:41:43
672
12:41:43
676

[salvin francis]

It looks like you are trying to extract time elapsed through JMeter's log.

Although, this is unrelated to your actual post, but have you tried adding a listener like 'View Results in Table' and then save that as a csv ?
You could open that csv directly in Excel and get all the data you need.

If you are trying to calculate something on the time elapsed such as average, median, 90% line, 99% line, Min, Max You could use the 'Aggregate Report' listener.

[Angus Ferguson]

Ok,

then something else is missing in my code because I get this result when printing it I think I got confused when debugging:

Number of requests at labelHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP sydneyHTTP

I have a small Servlet which calls a class.

public String analyzerReader(float loadTime) throws Exception {

        float fileRawLoadTime;

        String file_name = "/Users/isaac/Documents/filesRawDataTests/test-resultSidney.csv";

        String msn = "test";
        ReadFile file = new ReadFile(file_name);

        file.openFile();
      
        try {

            FileReader fr = new FileReader(file_name);
            BufferedReader lineReader = new BufferedReader(fr);
            String loadValeFile = "";
            String aLine;       
            int numberOfLines = 0;
          
            while ((aLine = lineReader.readLine()) != null) {

                Scanner sc = new Scanner(aLine).useDelimiter(";");
                System.out.println("" + sc.next());
                System.out.println("" + sc.next());

                msn = msn+sc.next();

                numberOfLines++;

            }
            lineReader.close();

        } catch (IOException ex) {
            Logger.getLogger(LoadStressAnalyzerReader.class.getName()).log(Level.SEVERE, null, ex);
        }

        return msn;

Any idea, please?

[Stephan van Hulst]

Well... yeah. You're appending the third token of each line to msn. The third token of each line is "HTTP sydney". It can only do this if it correctly reads "12:41:43" as the first token, and "287" as the second token. There is no error, I think you're confused.

[Angus Ferguson]

Why i need two

sc.next()

If I write this code

msn =sc.next();

and I return it to the Servlet I get

sydneyHTTP

Any idea, please?

[Stephan van Hulst]

Remove one of the two sc.next() calls?

[Angus Ferguson]

Then if I remove one it shows the first one

18:53:10

[Stephan van Hulst]

Do you have a code repository where you could publish an SSCCE showing your problem?

[Angus Ferguson]

I can send you a link to GIT with only the basic code

Does it helps?

[Stephan van Hulst]

I can run your code, but obviously I can't do much without having access to the data you're using. I don't have "test-resultSidney.csv".

[Angus Ferguson]

As I cant attach .page documents I ned you some rows just for run it.

timeStamp;elapsed;label;responseCode;threadName;success;bytes;grpThreads;allThreads;URL;Filename;Latency;Encoding;SampleCount;ErrorCount;Hostname;IdleTime;Connect																		
12:41:43;287;HTTP sydney;200;Thread Group 1-10;true;113887;12;12;https://www.domain.com/de/city/sydney;;223;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;84																		
12:41:43;495;HTTP sydney;200;Thread Group 1-8;true;113887;13;13;https://www.domain.com/de/city/sydney;;418;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;273																		
12:41:43;672;HTTP sydney;200;Thread Group 1-2;true;113887;13;13;https://www.domain.com/de/city/sydney;;594;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444																		
12:41:43;676;HTTP sydney;200;Thread Group 1-4;true;113887;13;13;https://www.domain.com/de/city/sydney;;609;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444																		
12:41:43;604;HTTP sydney;200;Thread Group 1-7;true;113887;13;13;https://www.domain.com/de/city/sydney;;510;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;366																		
12:41:43;130;HTTP sydney;200;Thread Group 1-10;true;113887;14;14;https://www.domain.com/de/city/sydney;;33;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;327;HTTP sydney;200;Thread Group 1-11;true;113887;14;14;https://www.domain.com/de/city/sydney;;201;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;167																		
12:41:43;131;HTTP sydney;200;Thread Group 1-8;true;113887;14;14;https://www.domain.com/de/city/sydney;;33;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;129;HTTP sydney;200;Thread Group 1-2;true;113887;14;14;https://www.domain.com/de/city/sydney;;31;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;138;HTTP sydney;200;Thread Group 1-4;true;113887;14;14;https://www.domain.com/de/city/sydney;;49;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;149;HTTP sydney;200;Thread Group 1-7;true;113887;14;14;https://www.domain.com/de/city/sydney;;54;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;131;HTTP sydney;200;Thread Group 1-10;true;113887;15;15;https://www.domain.com/de/city/sydney;;48;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;150;HTTP sydney;200;Thread Group 1-11;true;113887;15;15;https://www.domain.com/de/city/sydney;;45;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;179;HTTP sydney;200;Thread Group 1-2;true;113887;16;16;https://www.domain.com/de/city/sydney;;50;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;192;HTTP sydney;200;Thread Group 1-8;true;113887;16;16;https://www.domain.com/de/city/sydney;;58;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;182;HTTP sydney;200;Thread Group 1-4;true;113887;16;16;https://www.domain.com/de/city/sydney;;51;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;434;HTTP sydney;200;Thread Group 1-12;true;113887;16;16;https://www.domain.com/de/city/sydney;;267;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;212																		
12:41:44;187;HTTP sydney;200;Thread Group 1-7;true;113887;16;16;https://www.domain.com/de/city/sydney;;58;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;218;HTTP sydney;200;Thread Group 1-11;true;113887;17;17;https://www.domain.com/de/city/sydney;;74;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;251;HTTP sydney;200;Thread Group 1-10;true;113887;17;17;https://www.domain.com/de/city/sydney;;76;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;524;HTTP sydney;200;Thread Group 1-13;true;113887;18;18;https://www.domain.com/de/city/sydney;;310;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;224																		
12:41:44;212;HTTP sydney;200;Thread Group 1-2;true;113887;18;18;https://www.domain.com/de/city/sydney;;54;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;223;HTTP sydney;200;Thread Group 1-8;true;113887;18;18;https://www.domain.com/de/city/sydney;;89;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;235;HTTP sydney;200;Thread Group 1-12;true;113887;18;18;https://www.domain.com/de/city/sydney;;95;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;225;HTTP sydney;200;Thread Group 1-7;true;113887;18;18;https://www.domain.com/de/city/sydney;;97;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;250;HTTP sydney;200;Thread Group 1-4;true;113887;18;18;https://www.domain.com/de/city/sydney;;93;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;160;HTTP sydney;200;Thread Group 1-11;true;113887;19;19;https://www.domain.com/de/city/sydney;;60;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;212;HTTP sydney;200;Thread Group 1-10;true;113887;20;20;https://www.domain.com/de/city/sydney;;52;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:43;619;HTTP sydney;200;Thread Group 1-14;true;113887;20;20;https://www.domain.com/de/city/sydney;;361;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;255																		
12:41:44;212;HTTP sydney;200;Thread Group 1-13;true;113887;20;20;https://www.domain.com/de/city/sydney;;48;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;230;HTTP sydney;200;Thread Group 1-2;true;113887;20;20;https://www.domain.com/de/city/sydney;;62;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;219;HTTP sydney;200;Thread Group 1-8;true;113887;20;20;https://www.domain.com/de/city/sydney;;77;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;568;HTTP sydney;200;Thread Group 1-15;true;113887;20;20;https://www.domain.com/de/city/sydney;;374;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;276																		
12:41:44;203;HTTP sydney;200;Thread Group 1-7;true;113887;20;20;https://www.domain.com/de/city/sydney;;90;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;238;HTTP sydney;200;Thread Group 1-4;true;113887;21;21;https://www.domain.com/de/city/sydney;;85;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		
12:41:44;160;HTTP sydney;200;Thread Group 1-11;true;113887;21;21;https://www.domain.com/de/city/sydney;;84;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;0																		

Does it helps?

[Stephan van Hulst]

I'm sorry, I can't reproduce your problem, so unless you come up with an SSCCE for us, there's not much we can do for you.

[Angus Ferguson]

Is it not what I sent to you? A repository with the minimal code?

[Stephan van Hulst]

No. An SSCCE in this case would be a simple class in which the main method calls the method that attempts to read the values that you want from a big String that represents your text file and prints them to console.

For it to be an SSCCE, all we should have to do is paste your code in our IDE, and just hit the run button.

[salvin francis]

Isaac Ferguson wrote:Is it not what I sent to you? A repository with the minimal code?

We really want to help you with your problem, but we aren't able to reproduce your issue at our end, hence we are unable to help you.
Here is my version of an SSCCE for your code with Stephan van Hulst's solution:

public class Test {
	public static void main(String[] args) {
		String testLines[] = {
				"12:41:43;287;HTTP sydney;200;Thread Group 1-10;true;113887;12;12;https://www.domain.com/de/city/sydney;;223;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;84",
				"12:41:43;495;HTTP sydney;200;Thread Group 1-8;true;113887;13;13;https://www.domain.com/de/city/sydney;;418;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;273",
				"12:41:43;672;HTTP sydney;200;Thread Group 1-2;true;113887;13;13;https://www.domain.com/de/city/sydney;;594;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444",
				"12:41:43;676;HTTP sydney;200;Thread Group 1-4;true;113887;13;13;https://www.domain.com/de/city/sydney;;609;UTF-8;1;0;Isaacs-Mac-mini.fritz.box;0;444"};

		Test test = new Test();
		for (String singleLine : testLines) {
			String extracted = test.extractText(singleLine);
			if(extracted == null){
				System.out.println("Error: couldnt extract time taken for line :\n"+singleLine+"\n\n\n");
			}else{
				System.out.println(extracted);
			}
		}
	}

	private String extractText(String singleLine) {
		String returnString = null;
		try (Scanner sc = new Scanner(singleLine);) {
			sc.useDelimiter(";");
			sc.next();
			returnString = sc.next();
		} catch (Exception e) {
			// -- XXX: would use a logger here
		}
		return returnString;
	}

}

You are free to play with testLines[] array and add your own values. If you get the "Error: couldnt extract time taken for line ..." statement, maybe you can post that line here

[Angus Ferguson]

I made work that piece of code, and now I m integrating it into the MVC app with Servlets. It compiles etc, and it doesnt throws errors. For this line of code it doesnt returns any value.

 out.println("<h1>Number of requests at " + analyzerReader.conector(file_name) + "</h1>");

when debugging I get a string in the return statement.

Any idea,, please?

[Stephan van Hulst]

Why are you printing html?

What value are you expecting to see? What value does it return? TellTheDetails

[Angus Ferguson]

I would like to get back a String from the call to the method

[Angus Ferguson]

Now it works the code in the Servlet is like this:

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException, Exception {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        try {
            /* TODO output your page here. You may use following sample code. */
            out.println("<!DOCTYPE html>");
            out.println("<html>");
            out.println("<head>");
            out.println("<title>LeanRoute Stress Test Analyzer</title>");
            out.println("</head>");
            out.println("<body>");
          
            String file_name = "/Users/isaac/Documents/filesRawDataTests/test-resultSidney.csv";
     
            int loadTime = Integer.parseInt(request.getParameter("loadTime"));
            int loadUsers = Integer.parseInt(request.getParameter("loadUsers"));

            out.println("<h1>Number of requests at " + analyzerReader.conector(file_name, loadUsers, loadTime) + "</h1>");
            out.println("</body>");
            out.println("</html>");
           
        } finally {
            out.close();
        }

    }

Anyone know how to apply CSS styles to a Servlet in order to render it in the index.jsp?

[Stephan van Hulst]

Which method? Which return statement?

Again, please post an SSCCE, and describe what output you're expecting when you run it as-is.

[Angus Ferguson]

It already works well the line

analyzerReader.conector(file_name, loadUsers, loadTime)

returns a String properly. All is working now what I interestd is in apply CSS to that prints .out

[Stephan van Hulst]

You should be using a framework that handles output for you. MVC frameworks allow you to return a view that is built up using templates. You can then just refer to your CSS from your template.

Do you know about RESTful web services and MVC?