What Java class allows to write to a file, both in Binary and ASCII?

Question

I need to write files, with Headers in ASCII and values in Binary.

For now, I'm using this:

File file = new File("~/myfile");
FileOutputStream out = new FileOutputStream(file);
// Write in ASCII
out.write(("This is a header\n").getBytes());
// Write a byte[] is quite easy
byte[] buffer = new buffer[4];
out.write(buffer, 0, 4);
// Write an int in binary gets complicated
out.write(ByteBuffer.allocate(4).putInt(6).array());
//Write a float in binary gets even more complicated
out.write(ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN)
        .putFloat(4.5).array());

The problem is that it's very slow (in terms of performance) to write that way, way slower than writing the values in ASCII actually. But it should be shorter since in I'm writing less data.

I've looked at other Java classes, and it seems to me that they are either only for ASCII writing, or only for Binary writing.

Would you have any other proposition for this problem ?

Answer 1

You can use FileOutputStream to write binary. To include text you have to convert it to a byte[] before writing to the stream.

The problem is that it's very long to write that way, way longer than writing the values in ASCII actually. But it should be shorter since in I'm writing less data.

Mixing text and data is complex and error prone. The size of the data does matter, rather the complexity of the data is important. I suggest considering using DataOutputStream if you want to keep things simple.

To perform your example you can do

DataOutputStream out = new DataOutputStream(
    new BufferedOutputStream(
        new FileOutputStream("~/myfile")));
// Write in ASCII
out.write("This is a header\n".getBytes());
// Write a 32-bit int
out.writeInt(6);
//Write a float in binary
out.writeFloat(4.5f);

out.flush(); // the buffer.