当使用openFileInput找不到文件时，如何防止android应用崩溃

Question

I want to react to a situation that no file has been found using FileInputStream. When i ran an app that loads a file that doesn't exist it opens an android popup with force close. I would like to react to the situation by changing a text in a text view and saying that the file has not been found. i tried changing the exceptions to change a text view and show that a file has not been found and the app still crashes.

Here is the piece of code:

 FileInputStream fis = null;
    String collected = null;
    try {
        fis = openFileInput("test");
        byte[] dataArray = new byte[fis.available()];
        while (fis.read(dataArray) != -1){
            collected = new String(dataArray);
        }
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block

        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally{
        try {
            fis.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }


    tv.setText(collected);

Answer 1

To ensure that an Android application does not force-close, your options are: a) do not do anything that will cause an exception, b) catch your exception with your own try/catch block, c) install an application level uncaught exception handler. Option a is not too feasible, c is not very helpful, and based on your code snippet you seem to be trying b -- however there appears to be another exception that you're not catching with this. The contents of logcat will tell you what exception, and the stack trace will lead to a point in your code which needs the try/catch.