Java, regular expression catching multiple occurances of pattern

Question

This is my original String:

String response = "attributes[{"id":50,"name":super},{"id":55,"name":hello}]";

I'm trying to parse the String and extract all the id values e.g
50
55

Pattern idPattern = Pattern.compile("{\"id\":(.*),");
Matcher matcher = idPattern.matcher(response);

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

When i try to print the value i get an exception: java.util.regex.PatternSyntaxException: Illegal repetition
Not had much experience with regular expressions in the past but cannot find a simple solution to this online.
Appreciate any help!

score 3 · Answer 1 · answered Nov 08 '12 at 16:38

3

Pattern.compile("\"id\":(\\d+)");

answered Nov 08 '12 at 16:38

Madbreaks

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score 2 · Answer 2 · edited May 23 '17 at 10:24

2

{ is a reserved character in regular expressions and should be escaped.

\{\"id\":(.*?),

Edit : If you're going to be working with JSON, you should consider using a dedicated JSON parser. It will make your life much easier. See Parsing JSON Object in Java

edited May 23 '17 at 10:24

Community

1
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answered Nov 08 '12 at 16:38

Mike Park

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That `.*` is going to greedy match, is it not? – Madbreaks Nov 08 '12 at 16:39
@Madbreaks Yep you're right - I glossed over that part and just thought he wanted to know why it was failing to compile – Mike Park Nov 08 '12 at 16:43
Is see you fixed it, removed my -1. :) Oops, it won't let me until you edit your answer, maybe put a note in it that you fixed it. – Madbreaks Nov 08 '12 at 16:44

score 2 · Accepted Answer · answered Nov 08 '12 at 16:39

2

Don't use a greedy match operator like * with a . which matches any character. unnecessarily. If you want the digits extracted, you can use \d.

"id":(\d+)

Within a Java String,

Pattern.compile("\"id\":(\\d+)");

answered Nov 08 '12 at 16:39

Anirudh Ramanathan

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Java, regular expression catching multiple occurances of pattern

3 Answers3