HPACK

Download

HPACK can be downloaded from the Maven central repository. Add the following dependency section to your pom.xml file:

<dependency>
    <groupId>com.twitter</groupId>
    <artifactId>hpack</artifactId>
    <version>0.5.2</version>
</dependency>

Getting Started

This library provides support for compression of header sets into header blocks. The following code fragment demonstrates the use of Encoder and Decoder:

try {
  int maxHeaderSize = 4096;
  int maxHeaderTableSize = 4096;
  byte[] name = "name".getBytes();
  byte[] value = "value".getBytes();

  ByteArrayOutputStream out = new ByteArrayOutputStream();

  // encode header set into header block
  Encoder encoder = new Encoder(false, maxHeaderTableSize);
  encoder.encodeHeader(out, name, value);
  encoder.endHeaders(out);

  ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());

  HeaderListener listener = new HeaderListener() {
    @Override
    public void emitHeader(byte[] name, byte[] value) {
      // handle header field
    }
  };

  // decode header block into header set
  Decoder decoder = new Decoder(true, maxHeaderSize, maxHeaderTableSize);
  decoder.decode(in, listener);
  decoder.endHeaderBlock(listener);
} catch (IOException e) {
  // handle exception
}

Problems?

If you find any issues please report them or better, send a pull request.

Authors

Jeff Pinner https://twitter.com/jpinner
Bill Gallagher https://twitter.com/billjgallagher

License