Circular Buffers - com.Ostermiller.util Java Utilities

The com.Ostermiller.util package contains three flavors of circular buffer. Each type is presented here along with a simple example. For a more complex example that uses threads and blocks input, please see the unit test for these classes.

CircularObjectBuffer | CircularCharBuffer | CircularByteBuffer

// Create the buffer.
CircularObjectBuffer cob = new CircularObjectBuffer();

// Fill the buffer.
cob.write("Hello World!\n");

// Empty the buffer.
System.out.print((String)(cob.read()));

Circular Object Buffer

Implements the circular buffer producer/consumer model for Objects.

// Create the buffer.
CircularCharBuffer ccb = new CircularCharBuffer();

// Fill the buffer.
ccb.getWriter().write("Hello World!\n");
ccb.getWriter().close();

// Empty the buffer.
int c;
while ((c = ccb.getReader().read()) != -1){
    System.out.print((char)c);
}

Circular Character Buffer

Implements the circular buffer producer/consumer model for characters. Filling and emptying the buffer is done with standard Java Readers and Writers.

Using this class is a simpler alternative to using a PipedReader and a PipedWriter. PipedReaders and PipedWriters don't support the mark operation, don't allow you to control buffer sizes that they use, and have a more complicated API that requires a instantiating two classes and connecting them.

// Create the buffer.
CircularByteBuffer cbb = new CircularByteBuffer();

// Fill the buffer.
cbb.getOutputStream().write(
    new byte[]{
        'H','e','l','l','o',' ',
        'W','o','r','l','d','!','\n'
    }
);
cbb.getOutputStream().close();

// Empty the buffer.
int c;
while ((c = cbb.getInputStream().read()) != -1){
    System.out.print((char)c);
}

Circular Byte Buffer

Implements the circular buffer producer/consumer model for bytes. Filling and emptying the buffer is done with standard Java InputStreams and OutputStreams.

Using this class is a simpler alternative to using a PipedInputStream and a PipedOutputStream. PipedInputStreams and PipedOutputStreams don't support the mark operation, don't allow you to control buffer sizes that they use, and have a more complicated API that requires a instantiating two classes and connecting them.