Question

This is my original String named ‘response’:

String response = "attributes[{"displayName":"Joe Smith","fact":"super"},{"displayName":"Kieron Kindle","fact":"this is great"}]";

I’m trying to parse the String and extract all the id values e.g

String[0] = Joe Smith
String[1] = Kieron Kindle

Pattern idPattern = Pattern.compile("\"displayName\":(\\w)"); // regular expression
Matcher matcher = idPattern.matcher(response);

while(matcher.find()){
    System.out.println(matcher.group(1));
}

When i try to print the value nothing is printed to screen (no exception)
the regex expression looks for "displayName":" as a left bracket and " as right bracket then extracts any words (\\w) between them?
Appreciate any help!
Removed the \n characters from my regex, that was a formating mistake, sorry guys!

Answer 1

But why have you used a \n in your regex? That should be \". Also you have used \\w which matches just a single character. You need to use a quantifier with that. And a Reluctant one.

So, your modified regex is like this: –

Pattern.compile("\"displayName\":\"(\\w+?)\""); // This won't consider space

But, since your String can also contain space, so you should not use \\w. It will not match a space.

So, finally, you should use this regex, which matches any character in between two inverted commas, except inverted comma itself: –

Pattern.compile("\"displayName\":\"([^\"]+)\"");

With the above pattern substituted in your code, your output would be like this: –

"Joe Smith"
"Kieron Kindle"

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You can read more about Regex in these tutorials: –

• http://docs.oracle.com/javase/tutorial/essential/regex/
• http://www.vogella.com/articles/JavaRegularExpressions/article.html