Question

Could you please help me find a solution for this problem?

I am trying to make a java GUI with Swing components

The interface is supposed to accept a Windows path to a certain file and trigger a set of function on the file after pressing the submit button

Right now I have created the component to get the user input as:

JTextField introducedPath1 = new JTextField(50);

I tried to change the default Windows path obtained by copy pasting the path from explorer into an accepted File path:

File file;
String makeCanonicalPath=introducedPath1.getText().toString();
            makeCanonicalPath=makeCanonicalPath.replaceAll("\\", "/");
            file = new File(makeCanonicalPath);

But I keep getting this error:

Exception in thread "AWT-EventQueue-0" java.util.regex.PatternSyntaxException: Unexpected internal error near index 1

\
 ^
at java.util.regex.Pattern.error(Unknown Source)
at java.util.regex.Pattern.compile(Unknown Source)
at java.util.regex.Pattern.<init>(Unknown Source)

Which I assume it is caused by the default path in windows(ex:L:\practice\test) getting its ‘\’ interpreted as escape sequences.

Any help or suggestion will be appreciated

Answer 1

With replaceAll, you need to use java escaping for regular expressions, so

makeCanonicalPath.replaceAll("\\\\", "/");

Because it is not a text search-replace, but a regex one.

If you want text-based search-replace, use apache commons string replace, for example.

Also, one alternative is to use replace() – http://docs.oracle.com/javase/1.4.2/docs/api/java/lang/String.html#replace(char, char) instead of replaceAll – it would replace all occurrences without using regex, and since you only have one char to replace, it’d work.