Regex to Parse Block of text Similar to Java Properties File Format

For the input that you provided :

String text = "Lots of text..." + "\n" + "String=Value" + "\n" + "PackageName=com.company.package" + "\n" + "String=Value";

The code that YOU wrote:

Pattern pattern = Pattern.compile("PackageName=(.*)");
Matcher matcher = pattern.matcher(text);
if (matcher.find()) {
    String packageName = matcher.group(1);
    System.out.println(packageName);
}

Works fine, it does retrieve the package name.

Unless you have anything to add that will clarify the problem, and what is wrong, then this is not even a question, everything works. :)

Cheers, Eugene.

I think your problem might be in the String lines at the top. You cannot declare a String literal over multiple lines in Java, you need to separate them by \n characters:

String text = "Lots of text...\nString=Value\nPackageName=com.company.package\nString=Value";

To make it more readable, you can do this:

String text = "Lots of text...\n" 
            + "String=Value\n" 
            + "PackageName=com.company.package\n" 
            + "String=Value";

Once that change is made, the code you provide works fine for me on JDK6.

That said, here is the regex slightly improved:

Pattern pattern = Pattern.compile("PackageName\\s*=\\s*(.*)");
Matcher matcher = pattern.matcher(text);
if (matcher.find()) {
    String packageName = matcher.group(1);
}

The only change I made was to add \\s*: this means any whitespace (or none) so you can put PackageName = abc and have it work (note that the regex item itself is actually \s* but you have to escape the \ character in Java).

My java code

 String text = "Lots of text... String=Value    PackageName=com.company.package String=Value";
        Pattern pattern = Pattern.compile("PackageName=(.*)");
        Matcher matcher = pattern.matcher(text);
        if (matcher.find()) {
            String packageName = matcher.group(1);
            System.out.println(packageName);
        }

The result runs :

com.company.package String=Value