Byte array of unknown length in java

Question

I am constructing an array of bytes in java and I don't know how long the array will be.

I want some tool like Java's StringBuffer that you can just call .append(byte b) or .append(byte[] buf) and have it buffer all my bytes and return to me a byte array when I'm done. Is there a class that does for bytes what StringBuffer does for Strings? It does not look like the ByteBuffer class is what I'm looking for.

Anyone have a good solution?

Answer 1

Try ByteArrayOutputStream. You can use write( byte[] ) and it will grow as needed.

Answer 2

Just to extend the previous answer, you can use ByteArrayOutputStream and it's method public void write(byte[] b, int off, int len), where parameters are:

b - the data

off - the start offset in the data

len - the number of bytes to write

If you want to use it as a "byte builder" and insert byte by byte, you can use this:

byte byteToInsert = 100; ByteArrayOutputStream baos = new ByteArrayOutputStream(); baos.write(new byte[]{byteToInsert}, 0, 1); 

Then you can use baos.toString() method to convert the array to string. The advantage is when you need to set up encoding of input, you can simply use i.e.:

baos.toString("Windows-1250")