Regex - Match.end() is not correct

Question

I have a string (input), within the string I want to find the following patter:

String pattern = "(src=)(\".*\")";

Then my aim is to replace the content with the new value.

Pattern r = Pattern.compile(pattern);
Matcher m = r.matcher(input);

String toReplace = "TESTTEST";

if (m.find()) {

    StringBuilder res = new StringBuilder();

    int start = m.start();
    int end = m.end();  

    res = res.append(m.group(1)).append("\"").append(toReplace).append("\" ");

    StringBuilder build = new StringBuilder(input);

    build.replace(start, end, res.toString());
}

The problem is when I have for e.g. this text in the input string

<param src="hallo.gif" width="1024" height="768" />

and using the code above - I get following output:

<param src="TESTTEST" />

but it should be actually:

<param src="TESTTEST" width="1024" height="768" />

I have noticed already that m.end() doesn't deliver the correct value, but I have no clue why, I tried also with a dollar symbol at the end of pattern, but then m.find() stays false. Any idea?

because the regex is greedy... http://stackoverflow.com/q/1139171/2902116 — bluelDe, Oct 30 '15 at 12:33

score 2 · Accepted Answer · answered Oct 30 '15 at 12:34

2

Your regex is greedy - ".*" matches "hallo.gif" width="1024" height="768" (from the first to the last " in the string).

Make the regex lazy, and it should work:

String pattern = "(src=)(\".*?\")";

answered Oct 30 '15 at 12:34

Tim Pietzcker

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Regex - Match.end() is not correct

1 Answers1