wicket.protocol.http.request.WebExternalResourceRequestTarget.java Source code

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Here is the source code for wicket.protocol.http.request.WebExternalResourceRequestTarget.java

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/*
 * $Id: WebExternalResourceRequestTarget.java,v 1.1 2005/11/24 20:59:02 eelco12
 * Exp $ $Revision: 5991 $ $Date: 2006-06-02 01:27:33 +0200 (Fri, 02 Jun 2006) $
 * 
 * ==============================================================================
 * 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 wicket.protocol.http.request;

import java.io.IOException;
import java.io.InputStream;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import wicket.IRequestTarget;
import wicket.RequestCycle;
import wicket.WicketRuntimeException;
import wicket.protocol.http.WebApplication;
import wicket.protocol.http.WebRequestCycle;
import wicket.protocol.http.WebResponse;
import wicket.util.io.Streams;

/**
 * Request target that is not a Wicket resource. For example, such a resource
 * could denote an image in the web application directory (not mapped to a
 * Wicket servlet). NOTE: this target can only be used in a servlet environment
 * with {@link wicket.protocol.http.WebRequestCycle}s.
 * 
 * @author Eelco Hillenius
 */
public class WebExternalResourceRequestTarget implements IRequestTarget {
    /** log. */
    private static final Log log = LogFactory.getLog(WebExternalResourceRequestTarget.class);

    /** the relative url of the external resource. */
    private final String url;

    /**
     * Construct.
     * 
     * @param url
     *            the relative url of the external resource
     */
    public WebExternalResourceRequestTarget(String url) {
        if (url == null) {
            throw new IllegalArgumentException("Argument url must be not null");
        }

        this.url = url;
    }

    /**
     * Respond by trying to delegate getting the resource from the
     * {@link ServletContext} object and stream that to the client. If such a
     * resource is not found, a warning will be logged, and a 404 will be
     * issued.
     * 
     * @see wicket.IRequestTarget#respond(wicket.RequestCycle)
     */
    public void respond(RequestCycle requestCycle) {
        try {
            WebResponse webResponse = ((WebRequestCycle) requestCycle).getWebResponse();
            final ServletContext context = ((WebApplication) requestCycle.getApplication()).getServletContext();

            // Set content type
            webResponse.setContentType(context.getMimeType(url));
            final InputStream in = context.getResourceAsStream(url);
            if (in != null) {
                try {
                    // Copy resource input stream to servlet output stream
                    Streams.copy(in, webResponse.getHttpServletResponse().getOutputStream());
                } finally {
                    // NOTE: We only close the InputStream. The servlet
                    // container should close the output stream.
                    in.close();
                }
            } else {
                log.warn("the resource requested by request " + requestCycle.getRequest() + " was not found");
                HttpServletResponse httpServletResponse = webResponse.getHttpServletResponse();
                httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
            }
        } catch (IOException e) {
            throw new WicketRuntimeException("Cannot load static content for request " + requestCycle.getRequest(),
                    e);
        }
    }

    /**
     * Gets the url to the external resource.
     * 
     * @return the url to the external resource
     */
    public final String getUrl() {
        return url;
    }

    /**
     * @see wicket.IRequestTarget#detach(wicket.RequestCycle)
     */
    public void detach(RequestCycle requestCycle) {
    }

    /**
     * @see wicket.IRequestTarget#getLock(RequestCycle)
     */
    public Object getLock(RequestCycle requestCycle) {
        return null;
    }

    /**
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {
        if (obj instanceof WebExternalResourceRequestTarget) {
            WebExternalResourceRequestTarget that = (WebExternalResourceRequestTarget) obj;
            return url.equals(that.url);
        }
        return false;
    }

    /**
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        int result = "WebExternalResourceRequestTarget".hashCode();
        result += url.hashCode();
        return 17 * result;
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "[WebExternalResourceRequestTarget@" + hashCode() + " " + url + "]";
    }
}