org.mule.transport.legstar.http.LegstarHttpMessageDispatcher.java Source code

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Here is the source code for org.mule.transport.legstar.http.LegstarHttpMessageDispatcher.java

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/*******************************************************************************
 * Copyright (c) 2009 LegSem.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *     LegSem - initial API and implementation
 ******************************************************************************/
package org.mule.transport.legstar.http;

import java.io.IOException;
import java.net.URI;

import org.apache.commons.httpclient.HostConfiguration;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.mule.api.ExceptionPayload;
import org.mule.api.MuleEvent;
import org.mule.api.MuleException;
import org.mule.api.MuleMessage;
import org.mule.api.endpoint.OutboundEndpoint;
import org.mule.api.transformer.TransformerException;
import org.mule.api.transport.PropertyScope;
import org.mule.transport.http.HttpClientMessageDispatcher;
import org.mule.transport.http.HttpConstants;
import org.mule.transport.legstar.cixs.transformer.AbstractHostToExecRequestMuleTransformer;

/**
 * <code>LegstarMessageDispatcher</code> delegates most of its behavior
 * to <code>HttpClientMessageDispatcher</code>.
 */
public class LegstarHttpMessageDispatcher extends HttpClientMessageDispatcher {

    /** When channeled over http, the legstar payload must be binary. */
    private static final String LEGSTAR_HTTP_CONTENT_TYPE = "application/octet-stream";

    /** LegStar mainframe modules recognize this HTTP header for trace mode.*/
    private static final String LEGSTAR_HTTP_HEADER_TRACE_MODE = "CICSTraceMode";

    /** logger used by this class.   */
    private final Log _log = LogFactory.getLog(getClass());

    /**
     * Constructor.
     * @param endpoint the endpoint to dispatch to
     */
    public LegstarHttpMessageDispatcher(final OutboundEndpoint endpoint) {
        super(endpoint);
    }

    /** 
     * We override this method because we need to perform LegStar messaging specific
     * transformations and also need to force the http header content type.
     * {@inheritDoc}
     *  */
    public final HttpMethod getMethod(final MuleEvent event) throws TransformerException {

        if (_log.isDebugEnabled()) {
            _log.debug("Creating http method for endpoint " + getEndpoint());
        }

        HttpMethod httpMethod = super.getMethod(event);

        /* Force the content type expected by the Mainframe */
        httpMethod.removeRequestHeader(HttpConstants.HEADER_CONTENT_TYPE);
        httpMethod.addRequestHeader(HttpConstants.HEADER_CONTENT_TYPE, LEGSTAR_HTTP_CONTENT_TYPE);

        if (isHostTraceOn(event.getMessage()) || _log.isDebugEnabled()) {
            httpMethod.addRequestHeader(LEGSTAR_HTTP_HEADER_TRACE_MODE, "true");
        }

        return httpMethod;
    }

    /**
     * We need to override this in order to clean up some HTTP headers which
     * would percolate back to the client.
     * */
    @Override
    protected MuleMessage getResponseFromMethod(HttpMethod httpMethod, ExceptionPayload ep)
            throws IOException, MuleException {
        MuleMessage message = super.getResponseFromMethod(httpMethod, ep);
        message.removeProperty(HttpConstants.HEADER_CONTENT_LENGTH, PropertyScope.OUTBOUND);
        message.removeProperty(HttpConstants.HEADER_CONTENT_TYPE, PropertyScope.OUTBOUND);

        return message;
    }

    @Override
    protected HostConfiguration getHostConfig(URI uri) throws Exception {
        // Substitute a regular HTTP URI where the legstar scheme is used
        URI httpUri = new URI(uri.toString().replace("legstar:", "http:"));
        return super.getHostConfig(httpUri);
    }

    /**
     * @param esbMessage the mule message
     * @return true if the mainframe should trace execution requests
     */
    public boolean isHostTraceOn(final MuleMessage esbMessage) {
        return esbMessage.getInboundProperty(AbstractHostToExecRequestMuleTransformer.LEGSTAR_HOST_TRACE_ON_KEY,
                false);
    }

}