java regEx, really confused

Question

Please help in developing a regEx expression. My requirement is to validate the following string,

String="asdasd|adajjsd|asas,asdas|asda|sd";

pattern id [String]separatedByPipe[String]separatedByPipe[String]

ex:String="asdasd|adajjsd|asas".

The above pattern is repeated, separated by comma, if there are multiple Strings ex:String="asdasd|adajjsd|asas,asdas|asda|sd";

I can make an assumption that the pattern is going to repeat only max 3 times, ie at max 2 commas in my String.

Attached my testClass

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class TestReg {

public static void main(String[] args) {

    //String regex = "[a-z]+\\|[a-z]+,[a-z]+\\|[a-z]*";
    String regex = "([a-z]\\|[a-z]\\|[a-z]\\,?)+";
    //String regex = "[a-z]+\\|re{ 1}[a-z]+\\|re{ 1}[a-z]+[a-z]+\\|[a-z]+\\|[a-z]*";
    //String regex = "[a-z](|)[a-z](,)[a-z](|)[a-z]";
    //String pattern="([a-z]+@)([a-z]+)(\\.[a-z]+)"; 
    //String inputString1 = "shdifhsdui-asdasd,shdifhsdui|abc";


    //String inputString1 = "";//failed
    String inputString1 = "asdasd|adajjsd|asas,asdas|asda|sd";//success
    //String inputString1 = "asdasd|adasd-asdas|asdasd";//success
    //String inputString1 = "asdasd|adasd|asassa,asdas|asdasd";//failed
    Pattern pattern1 = Pattern.compile(regex);
    Matcher matcher1 = pattern1.matcher(inputString1);
    boolean result = matcher1.find();          
    System.out.println(result);
}

}

hi all ,

System.out.println ("asdasd|adajjsd|asa,s|sad|sdas,asd|as|as|da".matches ("([a-z]*\\|[a-z]*\\|[a-z]*\\,?)+"));

working like charm. So why the same is not working in my above class. Kindly help.Am using jdk1.5

You do not need to backslash-escape a , as it has no special meaning in regex. — Patashu
– Patashu, Commented May 31, 2013 at 9:50

Bohemian · Accepted Answer · 2013-05-31 10:01:10Z

1

This java regex will match your requirements:

"[a-z]+(\\|[a-z]+){2}(,[a-z]+(\\|[a-z]+){2})*"

That will validate the input, but to extract the parts I would simply use split() on commas, then for each part split on pipe:

for (String group : input.split(",")) {
    String[] parts = group.split("\\|");
    // do something with the parts
}

It's just two lines of code to get to your data.

edited May 31, 2013 at 10:01

answered May 31, 2013 at 9:51

Bohemian♦

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3 Comments

Valath Over a year ago

Valath Over a year ago

Your answer is correct if using ".matches()" method.I have edited the question. Please have a look. matcher() and matches(), giving different outputs.

Bohemian Over a year ago

I can get split to work, but with your example, are you expecting a blank field at the end?

anshulkatta · Accepted Answer · 2013-05-31 09:51:18Z

0

change the String regex to

String regex = "([a-z]*\\|[a-z]*\\|[a-z]*\\,?)+";

and then try

    String inputString1 = "asdasd|adajjsd|asas,asdas|asda|sd";
    String regex = "([a-z]*\\|[a-z]*\\|[a-z]*\\,?)+";
    Pattern pattern1 = Pattern.compile(regex);
    Matcher matcher1 = pattern1.matcher(inputString1);
    boolean result = matcher1.find();          

    System.out.println(inputString1.substring(matcher1.regionStart(), matcher1.regionEnd()));

answered May 31, 2013 at 9:51

anshulkatta

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2 Comments

Valath Over a year ago

Valath Over a year ago

I have edited the question. Please have a look. matcher() and matches(), giving different outputs.

epoch · Accepted Answer · 2013-05-31 09:52:33Z

0

Split on ,, then on |

String[] terms = string.split(",");
for (String term : terms) {
    String[] parts = term.split("\\|");
}

answered May 31, 2013 at 9:52

epoch

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1 Comment

Valath Over a year ago

I have edited the question. Please have a look. matcher() and matches(), giving different outputs.

Anirudha · Accepted Answer · 2013-05-31 09:56:38Z

0

Your can validate it using this regex

^(?!.*,$)[a-z]+(\\|[a-z]+,?)*$

edited May 31, 2013 at 9:56

answered May 31, 2013 at 9:51

Anirudha

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2 Comments

Anirudha Over a year ago

@SujeeshSValath you should specify all the valid and invalid combinations in your question..else no one would be able to help you

Valath Over a year ago

I have edited the question. Please have a look. matcher() and matches(), giving different outputs.

Jariya Nilesh · Accepted Answer · 2013-05-31 10:04:49Z

0

if you want to test above entire static string as one string then this regex pattern will help you .. but if you want to test the different string seprated by "|" then you need to take other regex pattern.

String regex = "([a-z]{6}\|[a-z]{7}\|[a-z]{4}\,[a-z]{5}\|[a-z]{2}?)+";

answered May 31, 2013 at 10:04

Jariya Nilesh

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1 Comment

Valath Over a year ago

Harish Kumar · Accepted Answer · 2013-05-31 10:09:02Z

0

Please try if this helps:

String regex = "[a-z]*\\|*,*[a-z]*";

And rest of the code should not need change.

answered May 31, 2013 at 10:09

Harish Kumar

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4 Comments

Valath Over a year ago

Harish Kumar Over a year ago

Please try this String regex = "[a-z]*\\|*,[a-z]*\\|";. Also please specify the combination that are possible from your requirements perspective. I go by Anirudh's point on this.

Valath Over a year ago

I have edited the question. Please have a look. matcher() and matches(), giving different outputs.

Harish Kumar Over a year ago

Pattern you are trying to match in your code is: one character|one character|one character,one character|one character|one character When you put * after [a-z] it matches 0 or more occurence of the character so it works when you use matches of String class

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