Question

I am trying to re-size an image, that part completed.
Then I’m trying to copy exif tags to new file.
I use ExifInterface to read tags.
I know it’s an interface not an object.
But When I try to use it for really big sized image, I get NullPointerException.
I get this error not for all the images.

07-25 11:59:23.870: WARN/System.err(1362): java.lang.NullPointerException
07-25 11:59:23.870: WARN/System.err(1362):     at android.media.ExifInterface.saveAttributes(ExifInterface.java:202)

How do I solve it?

Code to copy exif information

try {
    // copy paste exif information from original file to new
    // file
    ExifInterface oldexif = new ExifInterface(filePath);
    ExifInterface newexif = new ExifInterface(file.getPath());

    int build = Build.VERSION.SDK_INT;

    // From API 11
    if (build >= 11) {
        newexif.setAttribute("FNumber",
                oldexif.getAttribute("FNumber"));
        newexif.setAttribute("ExposureTime",
                oldexif.getAttribute("ExposureTime"));
        newexif.setAttribute("ISOSpeedRatings",
                oldexif.getAttribute("ISOSpeedRatings"));
    }
    // From API 9
    if (build >= 9) {
        newexif.setAttribute("GPSAltitude",
                oldexif.getAttribute("GPSAltitude"));
        newexif.setAttribute("GPSAltitudeRef",
                oldexif.getAttribute("GPSAltitudeRef"));
    }
    // From API 8
    if (build >= 8) {
        newexif.setAttribute("FocalLength",
                oldexif.getAttribute("FocalLength"));
        newexif.setAttribute("GPSDateStamp",
                oldexif.getAttribute("GPSDateStamp"));
        newexif.setAttribute("GPSProcessingMethod",
                oldexif.getAttribute("GPSProcessingMethod"));
        newexif.setAttribute("GPSTimeStamp",
                oldexif.getAttribute("GPSTimeStamp"));
    }
    newexif.setAttribute("DateTime",
            oldexif.getAttribute("DateTime"));
    newexif.setAttribute("Flash", oldexif.getAttribute("Flash"));
    newexif.setAttribute("GPSLatitude",
            oldexif.getAttribute("GPSLatitude"));
    newexif.setAttribute("GPSLatitudeRef",
            oldexif.getAttribute("GPSLatitudeRef"));
    newexif.setAttribute("GPSLongitude",
            oldexif.getAttribute("GPSLongitude"));
    newexif.setAttribute("GPSLongitudeRef",
            oldexif.getAttribute("GPSLongitudeRef"));

    // You need to update this with your new height width
    newexif.setAttribute("ImageLength",
            oldexif.getAttribute("ImageLength"));
    newexif.setAttribute("ImageWidth",
            oldexif.getAttribute("ImageWidth"));

    newexif.setAttribute("Make", oldexif.getAttribute("Make"));
    newexif.setAttribute("Model", oldexif.getAttribute("Model"));
    newexif.setAttribute("Orientation",
            oldexif.getAttribute("Orientation"));
    newexif.setAttribute("WhiteBalance",
            oldexif.getAttribute("WhiteBalance"));

    newexif.saveAttributes();

    Toast.makeText(getApplicationContext(),
            "Image resized & saved successfully",
            Toast.LENGTH_SHORT).show();
} catch (Exception e) {
    e.printStackTrace();
}

Additional onFly information:

New file is created when I’m trying to read both the file:

---

Debug watch on oldexif

---

Debug watch on newexif

---

Testing image

http://vikaskanani.files.wordpress.com/2011/07/test.jpg

---

Using Android emulator for sdk 2.1

Answer 1

You are passing a null value somewhere in the saveAttributes.

Debugging NullPointerExceptions is very easy, providing you have the sourcecode.

Below you can find the sourcecode for the ExifInterface for Android 2.1

http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.1_r2/android/media/ExifInterface.java#ExifInterface

line 202 contains this :

sb.append(val.length() + " ");

Only thing that can be null here is val. (one of the values you’re passing in the saveAttributes method).

I would suggest double checking the values you’re passing onto that value, and watch out for null values.