Spring Framework example source code file (HessianExporter.java)

This example Spring Framework source code file (HessianExporter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

beaninitializationexception, class, classloader, constructor, hessian, hessian, hessianskeleton, hessianskeleton, initializingbean, io, object, object, reflection, serializerfactory, serializerfactory, throwable

The Spring Framework HessianExporter.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.remoting.caucho;

import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Constructor;

import com.caucho.hessian.io.SerializerFactory;
import com.caucho.hessian.server.HessianSkeleton;
import org.apache.commons.logging.Log;

import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.remoting.support.RemoteExporter;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;

/**
 * General stream-based protocol exporter for a Hessian endpoint.
 *
 * <p>Hessian is a slim, binary RPC protocol.
 * For information on Hessian, see the
 * <a href="http://www.caucho.com/hessian">Hessian website.
 *
 * <p>This exporter will work with both Hessian 2.x and 3.x (respectively
 * Resin 2.x and 3.x), autodetecting the corresponding skeleton class.
 * As of Spring 2.0, it is also compatible with the new Hessian 2 protocol
 * (a.k.a. Hessian 3.0.20+), while remaining compatible with older versions.
 *
 * @author Juergen Hoeller
 * @since 2.5.1
 * @see #invoke(java.io.InputStream, java.io.OutputStream)
 * @see HessianServiceExporter
 * @see SimpleHessianServiceExporter
 */
public class HessianExporter extends RemoteExporter implements InitializingBean {

	private static final boolean hessian2Available =
			ClassUtils.isPresent("com.caucho.hessian.io.Hessian2Input", HessianServiceExporter.class.getClassLoader());


	private SerializerFactory serializerFactory = new SerializerFactory();

	private Log debugLogger;

	private HessianSkeletonInvoker skeletonInvoker;


	/**
	 * Specify the Hessian SerializerFactory to use.
	 * <p>This will typically be passed in as an inner bean definition
	 * of type <code>com.caucho.hessian.io.SerializerFactory,
	 * with custom bean property values applied.
	 */
	public void setSerializerFactory(SerializerFactory serializerFactory) {
		this.serializerFactory = (serializerFactory != null ? serializerFactory : new SerializerFactory());
	}

	/**
	 * Set whether to send the Java collection type for each serialized
	 * collection. Default is "true".
	 */
	public void setSendCollectionType(boolean sendCollectionType) {
		this.serializerFactory.setSendCollectionType(sendCollectionType);
	}

	/**
	 * Set whether Hessian's debug mode should be enabled, logging to
	 * this exporter's Commons Logging log. Default is "false".
	 * @see com.caucho.hessian.client.HessianProxyFactory#setDebug
	 */
	public void setDebug(boolean debug) {
		this.debugLogger = (debug ? logger : null);
	}


	public void afterPropertiesSet() {
		prepare();
	}

	/**
	 * Initialize this exporter.
	 */
	public void prepare() {
		HessianSkeleton skeleton = null;

		try {
			try {
				// Try Hessian 3.x (with service interface argument).
				Constructor ctor = HessianSkeleton.class.getConstructor(new Class[] {Object.class, Class.class});
				checkService();
				checkServiceInterface();
				skeleton = (HessianSkeleton)
						ctor.newInstance(new Object[] {getProxyForService(), getServiceInterface()});
			}
			catch (NoSuchMethodException ex) {
				// Fall back to Hessian 2.x (without service interface argument).
				Constructor ctor = HessianSkeleton.class.getConstructor(new Class[] {Object.class});
				skeleton = (HessianSkeleton) ctor.newInstance(new Object[] {getProxyForService()});
			}
		}
		catch (Throwable ex) {
			throw new BeanInitializationException("Hessian skeleton initialization failed", ex);
		}

		if (hessian2Available) {
			// Hessian 2 (version 3.0.20+).
			this.skeletonInvoker = new Hessian2SkeletonInvoker(skeleton, this.serializerFactory, this.debugLogger);
		}
		else {
			// Hessian 1 (version 3.0.19-).
			this.skeletonInvoker = new Hessian1SkeletonInvoker(skeleton, this.serializerFactory);
		}
	}


	/**
	 * Perform an invocation on the exported object.
	 * @param inputStream the request stream
	 * @param outputStream the response stream
	 * @throws Throwable if invocation failed
	 */
	public void invoke(InputStream inputStream, OutputStream outputStream) throws Throwable {
		Assert.notNull(this.skeletonInvoker, "Hessian exporter has not been initialized");
		ClassLoader originalClassLoader = overrideThreadContextClassLoader();
		try {
			this.skeletonInvoker.invoke(inputStream, outputStream);
		}
		finally {
			resetThreadContextClassLoader(originalClassLoader);
		}
	}

}