Glassfish example source code file (OSGiResourceServlet.java)

This example Glassfish source code file (OSGiResourceServlet.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 - Glassfish tags/keywords

handling, http, httpcontext, httpservletresponse, io, ioexception, ioexception, net, network, osgiresourceservlet, osgiresourceservlet, outputstream, request, response, servlet, string, string, stringbuilder, todo, urlconnection

The Glassfish OSGiResourceServlet.java source code

/*
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 *
 * Copyright (c) 2009-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
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 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
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 */

package org.glassfish.osgihttp;

import org.osgi.service.http.HttpContext;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import java.io.OutputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URI;
import java.net.URISyntaxException;

/**
 * @author Sanjeeb.Sahoo@Sun.COM
 */
public class OSGiResourceServlet extends HttpServlet {

    private String alias;
    private String name;
    private HttpContext httpContext;

    public OSGiResourceServlet(String alias, String name, HttpContext httpContext) {
        this.alias = alias;
        this.name = name;
        this.httpContext = httpContext;
    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        final String resPath = getResourcePath(req);
        URL url = httpContext.getResource(resPath);
        if (url == null) {
            resp.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        }
        // contentType must be set before writing anything to the stream
        // as for long data,m stream gets flushed before we have finished
        // writing everything.
        String mimeType = httpContext.getMimeType(resPath);
        if (mimeType == null) {
            mimeType = getServletConfig().getServletContext().getMimeType(resPath);
        }
        resp.setContentType(mimeType);
        URLConnection conn = url.openConnection();
        int writeCount = writeToStream(conn, resp.getOutputStream());
        resp.setContentLength(writeCount);
        resp.setStatus(HttpServletResponse.SC_OK);
    }

    private String getResourcePath(HttpServletRequest req) {
        String servletPath = req.getServletPath();
        assert(alias.equals(servletPath));
        String contextPath = req.getContextPath();
        final String requestURI;
        try {
            requestURI = new URI(req.getRequestURI()).normalize().toString();
        } catch (URISyntaxException e) {
            throw new RuntimeException(e); // TODO(Sahoo): Proper Exception Handling
        }
        String requestedPath = requestURI.substring(contextPath.length());
        StringBuilder mappedPath = new StringBuilder(requestedPath);
        String internalName = name == "/" ? "" : name;
        mappedPath.replace(0, servletPath.length(), internalName);
//        System.out.println("Mapped [" + requestedPath + "] to [" + mappedPath + "]");
        return mappedPath.toString();
    }

    private int writeToStream(URLConnection connection, OutputStream os) throws IOException {
        InputStream is = connection.getInputStream();
        try {
            byte[] buf = new byte[8192];
            int readCount = is.read(buf);
            int writeCount = 0;
            while (readCount!=-1) {
                os.write(buf, 0, readCount);
                writeCount += readCount;
                readCount = is.read(buf);
            }
            return writeCount;
        } finally {
            if (is != null) is.close();
        }
    }
}