ArrayIndexOutOfBoundsException when read from buffer

Question

My app send data (string or bytes) to another app copy via Bluetooth. I try to send big text or bytes[] and get this error:

FATAL EXCEPTION: Thread-8297
        java.lang.ArrayIndexOutOfBoundsException: length=1024; index=1024
            at com.ramimartin.multibluetooth.bluetooth.BluetoothRunnable.run(BluetoothRunnable.java:147)
            at java.lang.Thread.run(Thread.java:841)

So, why? Code from line

BluetoothRunnable.java:147

is:

while(bytesRead == bufferSize && buffer[bufferSize] != 0) {

Full code:

        int bufferSize = 1024;
        int bytesRead;
        byte[] buffer = new byte[bufferSize];
                    try {
                        if(this.mInputStream != null) {
                            bytesRead = this.mInputStream.read(buffer);
                            ByteBuffer bbuf = ByteBuffer.allocate(bytesRead);
                            if(bytesRead != -1) {
                                while(bytesRead == bufferSize && buffer[bufferSize] != 0) {
                                    bbuf.put(buffer, 0, bytesRead);
                                    if(this.mInputStream == null) {
                                        return;
                                    }

                                    bytesRead = this.mInputStream.read(buffer);
                                }

                                bbuf.put(buffer, 0, bytesRead);
                            }

                            EventBus.getDefault().post(new BluetoothCommunicatorBytes(bbuf.array()));
                            continue;
                        }
                    } catch (IOException var8) {
                        Log.e(TAG, "===> Error Received Bytes IOException  : " + var8.getMessage());
                        continue;
                    }

Arrays in Java are 0-indexed. – azurefrog Nov 13 '17 at 05:39 — azurefrog, Nov 13 '17 at 05:39

Pritam Banerjee · Accepted Answer · 2017-11-13T05:45:24.877

0

This should be:

while(bytesRead == bufferSize && buffer[bufferSize - 1] != 0)

Also there might be times when bufferSize is than 1.

And the way to read an array is:

int arr[] = new int[10];

The max index in the above case will be:

arr[9]

as index starts from 0.

edited Nov 13 '17 at 05:45

answered Nov 13 '17 at 05:43

Pritam Banerjee

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Okay, I will try it now – РСИТ _ Nov 13 '17 at 05:45
So, I was try your example, but now I getting error "java.nio.BufferOverflowException" at line with code "bbuf.put(buffer, 0, bytesRead);". I need to set bufferSize to bigger int? – РСИТ _ Nov 13 '17 at 07:23
1

Issue was resolved. – РСИТ _ Nov 13 '17 at 11:12

ArrayIndexOutOfBoundsException when read from buffer

1 Answers1