Question

I have a FloatBuffer of known size and just want to dump the data to a file (in binary) for inspection outside my app. What’s the easiest way to do this?

Answer 1

UPDATE FOR BINARY OUTPUT:

// There are dependencies on how you create your floatbuffer for this to work // I suggest starting with a byte buffer and using asFloatBuffer() when // you need it as floats. // ByteBuffer b = ByteBuffer.allocate(somesize); // FloatBuffer fb = b.asFloatBuffer(); // There will also be endiance issues when you write binary since // java is big-endian. You can adjust this with Buffer.order(...) // b.order(ByteOrder.LITTLE_ENDIAN) // If you're using a hex-editor you'll probably want little endian output // since most consumer machines (unless you've got a sparc / old mac) are little   FileOutputStream fos = new FileOutputStream('some_binary_output_file_name'); FileChannel channel = fos.getChannel();  channel.write(byteBufferBackingYourFloatBuffer);  fos.close(); 

TEXT OUTPUT: Since you want this to be viewable I assume you want a text file. You’ll want to use a PrintStream.

// Try-catch omitted for simplicity  PrintStream ps = new PrintStream('some_output_file.txt'); for(int i = 0; i < yourFloatBuffer.capacity(); i++) {    // put each float on one line    // use printf to get fancy (decimal places, etc)    ps.println(yourFloagBuffer.get(i)); }  ps.close(); 

Didn’t have time to post a full raw/binary (non-text) version of this. If you want to do that use a FileOutputStream, get the FileChannel, and directly write the FloatBuffer (since it’s a ByteBuffer)