Hessian

Hessian is a binary serialization protocol with support for RPC. It provides cross-language binary object serialization with efficiencies better than java.io serialization

The Hessian serialization API resembles java.io ObjectOutputStream serialization. The general steps are to create a Hessian2Output around any OutputStream and write data to the stream.

Serialization


ByteArrayOutputStream bos = new ByteArrayOutputStream();
Hessian2Output out = new Hessian2Output(bos);

out.startMessage();
out.writeInt(2);

Car car1 = new Car(Model.EDSEL, Color.GREEN, 1954);
out.writeObject(car1);

Car car2 = new Car(Model.MODEL_T, Color.BLACK, 1937);
out.writeObject(car2);

out.completeMessage();
out.close();

byte []data = bos.toByteArray();

Deserialization


ByteArrayInputStream bin = new ByteArrayInputStream(data);
Hessian2Input in = new Hessian2Input(bin);

in.startMessage();

ArrayList list = new ArrayList();

int length = in.readInt();

for (int i = 0; i < length; i++) {
  list.add(in.readObject());
}

in.completeMessage();

in.close();
bin.close();

Compression

Deflation

Deflation envelope = new Deflation();

ByteArrayOutputStream bos = new ByteArrayOutputStream();

HessianFactory factory = new HessianFactory();
Hessian2Output out = factory.createHessian2Output(bos);

out = envelope.wrap(out);
out.startMessage();

Car car1 = new Car(Model.EDSEL, Color.GREEN, 1954);
out.writeObject(car1);

out.completeMessage();
out.close();

byte []data = bos.toByteArray();

Inflation

Deflation envelope = new Deflation();

ByteArrayInputStream bin = new ByteArrayInputStream(data);

HessianFactory factory = new HessianFactory();
Hessian2Input in = factory.createHessian2Input(bin);

in = envelope.unwrap(in);

in.startMessage();

Object value = in.readObject();

in.completeMessage();

MathService.java (remote interface)

package example;

public interface MathService {
  public int add(int a, int b);
}

MathServiceImpl.java

package example;

public class MathServiceImpl implements MathService {
  public int add(int a, int b)
  {
    return a + b;
  }
}

Server configuration resin-web.xml

<web-app xmlns="http://caucho.com/ns/resin">

  <servlet-mapping url-pattern="/math/*"
                   servlet-class="example.MathService">
    <protocol uri="hessian:"/>
  </servlet-mapping>

  <remote-client name="math">
    <uri>hessian:url=${webApp.url}/math/</uri>
    <interface>example.MathService</interface>
  </remote-client>

</web-app>

JSP Java client

<%@ page import="javax.inject.Inject" %>
<%@ page import="example.MathService" %>
<%!
@Inject MathService math;
%>
<pre>
3 + 2 = <%= math.add(3, 2) %>
3 - 2 = <%= math.sub(3, 2) %>
3 * 2 = <%= math.mul(3, 2) %>
3 / 2 = <%= math.div(3, 2) %>
</pre>

Resin Documentation

hessian

Hessian Protocol

Hessian Serialization

Compression

Hessian Web Service