JAVA + try catch(FileNotFoundException e) going in catch(Exception e)?

java try-catch filenotfoundexception
user706058 picture user706058 · May 5, 2011 · Viewed 59.2k times · Source

I have some command which creates a file on disk. Because the folder in which the file has to be created is dynamic, I have a catch(FileNotFoundException e). In the same try block, I already have a catch(Exception e) block. For some reason, when I run my code and the folder does not exists yet, the catch(Exception e) block is used, not the FileNotFoundException one.

The debugger is clear though (to me at least), showing a FileNotFoundException: java.io.FileNotFoundException: c:\mydata\2F8890C2-13B9-4D65-987D-5F447FF0DDA7\filename.png (The system cannot find the path specified)

Any idea why it doesn't go into the FileNotFoundException block? Thanks;

CODE:

import java.io.FileNotFoundException;

try{
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Rectangle screenRectangle = new Rectangle(screenSize);
    Robot robot = new Robot();
    BufferedImage image = robot.createScreenCapture(screenRectangle);
    ImageIO.write(image, "png", new File(fileName));
}
catch (FileNotFoundException e){
    // do stuff here..
    return false;
}
catch(Exception e){
    // do stuff here..
    return = false;
}

Answer

jefflunt picture jefflunt · May 5, 2011

It's also possible that the specific issue you're having isn't a FileNotFoundException. By using the "Exception" in a catch block (which is the parent class to all Exceptions) this is effectively a "catch all", since it will run if there is an `Exception or any of its subclasses thrown.

Try the following change:

...

catch (Exception e) {
  System.out.println(e.getClass());
}
...

This will tell you the specific class of the Exception being caught by this block. I'll bet you'll find that the Exception is actually an instance of a subclass (such as IOException, for example).

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