This is deliberate. The contents of the "file" may not be available as a file. Remember you are dealing with classes and resources that may be part of a JAR file or other kind of resource. The classloader does not have to provide a file handle to the resource, for example the jar file may not have been expanded into individual files in the file system.

Anything you can do by getting a java.io.File could be done by copying the stream out into a temporary file and doing the same, if a java.io.File is absolutely necessary.

if netclient.p is inside a JAR file, it won't have a path because that file is located inside other file. in that case, the best path you can have is really file:/path/to/jarfile/bot.jar!/config/netclient.p.

You need to understand the path within the jar file.
Simply refer to it relative. So if you have a file (myfile.txt), located in foo.jar under the \src\main\resources directory (maven style). You would refer to it like:

src/main/resources/myfile.txt

If you dump your jar using jar -tvf myjar.jar you will see the output and the relative path within the jar file, and use the FORWARD SLASHES.

A File is an abstraction for a file in a filesystem, and the filesystems don't know anything about what are the contents of a JAR.

Try with an URI, I think there's a jar:// protocol that might be useful for your purpouses.

follow code!

/src/main/resources/file

streamToFile(getClass().getClassLoader().getResourceAsStream("file"))

public static File streamToFile(InputStream in) {
    if (in == null) {
        return null;
    }

    try {
        File f = File.createTempFile(String.valueOf(in.hashCode()), ".tmp");
        f.deleteOnExit();

        FileOutputStream out = new FileOutputStream(f);
        byte[] buffer = new byte[1024];

        int bytesRead;
        while ((bytesRead = in.read(buffer)) != -1) {
            out.write(buffer, 0, bytesRead);
        }

        return f;
    } catch (IOException e) {
        LOGGER.error(e.getMessage(), e);
        return null;
    }
}

It may be a little late but you may use my library KResourceLoader to get a resource from your jar:

File resource = getResource("file.txt")

Inside your ressources folder (java/main/resources) of your jar add your file (we assume that you have added an xml file named imports.xml), after that you inject ResourceLoader if you use spring like bellow

@Autowired
private ResourceLoader resourceLoader;

inside tour function write the bellow code in order to load file:

    Resource resource = resourceLoader.getResource("classpath:imports.xml");
    try{
        File file;
        file = resource.getFile();//will load the file
...
    }catch(IOException e){e.printStackTrace();}

Maybe this method can be used for quick solution.

public class TestUtility
{ 
    public static File getInternalResource(String relativePath)
    {
        File resourceFile = null;
        URL location = TestUtility.class.getProtectionDomain().getCodeSource().getLocation();
        String codeLocation = location.toString();
        try{
            if (codeLocation.endsWith(".jar"){
                //Call from jar
                Path path = Paths.get(location.toURI()).resolve("../classes/" + relativePath).normalize();
                resourceFile = path.toFile();
            }else{
                //Call from IDE
                resourceFile = new File(TestUtility.class.getClassLoader().getResource(relativePath).getPath());
            }
        }catch(URISyntaxException ex){
            ex.printStackTrace();
        }
        return resourceFile;
    }
}

This Class function can get absolute file path by relative file path in .jar file.

public class Utility {

    public static void main(String[] args) throws Exception {
        Utility utility = new Utility();
        String absolutePath = utility.getAbsolutePath("./absolute/path/to/file");
    }

    public String getAbsolutePath(String relativeFilePath) throws IOException {
        URL url = this.getClass().getResource(relativeFilePath);
        return url.getPath();
    }
}

If target file is same directory with Utility.java, your input will be ./file.txt.

When you input only / on getAbsolutePath(), it returns /Users/user/PROJECT_NAME/target/classes/. This means you can select the file like this /com/example/file.txt.