Handling null pointer exception

Question

I am getting NullPointerException in the code.I want to handle it. In the following code i have specified the line in which the null pointer exception occurs.

 public static void mapPcm16bitLittleEndian2Float(final byte[] pcm16bitBytes,
            final int offsetInput,
            final float[] samples,
            final int offsetOutput,
            final int length) {
        if (pcm16bitBytes.length - offsetInput < 2 * length) {
            throw new IllegalArgumentException("Insufficient Samples to convert to floats");
        }
        if (samples.length - offsetOutput < length) {
            throw new IllegalArgumentException("Insufficient float buffer to convert the samples");// Getting null pointer exception here.
        }
        for (int i = 0; i < length; i++) {
            samples[offsetOutput + i] = ((pcm16bitBytes[offsetInput + 2 * i] & 0xff) | (pcm16bitBytes[offsetInput + 2 * i + 1] << 8)); // no & 0xff at the end to keep the sign
        }


and

 public boolean processData(final byte[] data,
            final int offset,
            final int len) {
        // converty raw bytes into float samples
        mapPcm16bitLittleEndian2Float(data, offset, rawData, 0, len / 2);// getting null pointer exception
        // encode the bitstream
        return processData(rawData, len / 2);
    }

Please help me getting out of this.

Post the full stack trace. The indicated line is probably one frame to early, since no pointer access happens right there, but in the body of the called method. — hiergiltdiestfu, Aug 07 '14 at 09:34

score 1 · Answer 1 · answered Aug 07 '14 at 09:34

1

One of the arrays you are referencing is null, hence referencing its length property will throw a NullPointerException.

You should check for both of your arrays being null (== null) to handle this Exception, and act accordingly (e.g. rethrow an IllegalArgumentException).

answered Aug 07 '14 at 09:34

Mena

47,782
11
87
106

@ Mena Thanks for the above coding.it works.getting null pointer exception in public boolean processData(final float[] data, final int numSamples) { int numSamplesRequired = channels * frameSize; if (numSamples != numSamplesRequired) { throw new IllegalArgumentException("SpeexEncoder requires " + numSamplesRequired + " samples to process a Frame, not " + numSamples ); } // encode the bitstream if (channels==2) { Stereo.encode(bits, data, frameSize); } encoder.encode(bits, data); return true; } – – user3912813 Aug 07 '14 at 10:36

score 0 · Answer 2 · answered Aug 07 '14 at 09:51

0

As suggested by Mena, null pointer check is a must.

Hope the below code snippet helps :

 public static void mapPcm16bitLittleEndian2Float(final byte[] pcm16bitBytes,
                final int offsetInput,
                final float[] samples,
                final int offsetOutput,
                final int length) {


            if(pcm16bitBytes != null && pcm16bitBytes.length >0 && samples != null && samples.length >0){
                System.out.println("If the arrays are null ,should not enter this block");
                if (pcm16bitBytes.length - offsetInput < 2 * length) {
                    throw new IllegalArgumentException("Insufficient Samples to convert to floats");
                }
                if (samples.length - offsetOutput < length) {
                    throw new IllegalArgumentException("Insufficient float buffer to convert the samples");// Getting null pointer exception here.
                }

                for (int i = 0; i < length; i++) {
                    samples[offsetOutput + i] = ((pcm16bitBytes[offsetInput + 2 * i] & 0xff) | (pcm16bitBytes[offsetInput + 2 * i + 1] << 8)); // no & 0xff at the end to keep the sign
                }


            }
        }

Regards,Madhu

answered Aug 07 '14 at 09:51

Madhu Bose

371
4
16

@ Madhu Bose Thanks for the above coding.it works.getting null pointer exception in public boolean processData(final float[] data, final int numSamples) { int numSamplesRequired = channels * frameSize; if (numSamples != numSamplesRequired) { throw new IllegalArgumentException("SpeexEncoder requires " + numSamplesRequired + " samples to process a Frame, not " + numSamples ); } // encode the bitstream if (channels==2) { Stereo.encode(bits, data, frameSize); } encoder.encode(bits, data); return true; } – user3912813 Aug 07 '14 at 10:34
Thanks user3912813, Am glad it helped :) .Request you to accept my answer . – Madhu Bose Aug 07 '14 at 11:04
@ Madhu Bose Please help me with previous coding.. Please – user3912813 Aug 07 '14 at 11:12
Not getting you ? previous coding?? – Madhu Bose Aug 07 '14 at 11:14
Are you taking about the below issue which you are facing?http://stackoverflow.com/questions/25181006/handling-arraystoreexception – Madhu Bose Aug 07 '14 at 11:16

Handling null pointer exception

2 Answers2