I am a bit confused with path in Java (using Eclipse). This is my file structure:
Folder
Subfolder
file.txt
jarfile.jar
So, I am trying to make the jar file parse data from file.txt and I use the following code:
Scanner in = new Scanner(this.getClass().getResourceAsStream("./Subfolder/file.txt"));
I have made a runnable jar file with Eclipse, put it in the Folder, but it does not work. What is it that I am doing wrong?
Since you use a resource file via a Class object, the path to the resource must be absolute:
getClass().getResourceAsStream("/Subfolder/file.txt");
Note that doing what you do is a bad idea, that is, opening a scanner on a resource which you don't have a reference to:
new Scanner(someInputStreamHere());
you have no reference to that input stream, therefore you cannot close it.
What is more, .getResource*() return null if the resource does not exist; in this case you'll get an NPE!
Recommended if you use Java 6 (using Guava's Closer):
final URL url = getClass().getResource("/path/to/resource");
if (url == null) // Oops... Resource does not exist
barf();
final Closer closer = Closer.create();
final InputStream in;
final Scanner scanner;
try {
in = closer.register(url.openStream());
scanner = closer.register(new Scanner(in));
// do stuff
} catch (IOException e) {
throw closer.rethrow(e);
} finally {
closer.close();
}
If you use Java 7, just use a try-with-resources statement:
final URL url = getClass().getResource("/path/to/resource");
if (url == null) // Oops... Resource does not exist
barf();
final InputStream in;
final Scanner scanner;
try (
in = url.openStream();
scanner = new Scanner(in);
) {
// do stuff
} catch (IOException e) {
// deal with the exception if needed; or just declare it at the method level
}
Just as an example because java is platform independent look at getting the relative absolute or canonical path as needed I hope this gives you an idea of what to do.
/**
* This method reads the AcronymList.xlsx and is responsible for storing historical acronyms
* and definitions.
* @throws FileNotFoundException
* @throws IOException
* @throws InvalidFormatException
*/
public file readAcronymList() throws FileNotFoundException, IOException, InvalidFormatException {
String accListFile = new File("src\\org\\alatecinc\\acronymfinder\\dal\\acIgnoreAddList\\AcronymList.xlsx").getCanonicalPath();
File acFile = new File(accListFile).getAbsoluteFile();
return acFile;
}
Why resource? Is the txt file embedded in the Jar file? It will load the file from the jar.
Just use a File or FileInputStream with the path you already put.
(new java.io.File(".").getCanonicalPath().