org.onebusaway.presentation.impl.ProxyServlet.java Source code

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Here is the source code for org.onebusaway.presentation.impl.ProxyServlet.java

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/**
 * Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
 *
 * 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.onebusaway.presentation.impl;

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

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;

public class ProxyServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    private String _target;

    private String _source;

    @Override
    public void init(ServletConfig config) throws ServletException {
        _target = config.getInitParameter("target");
        if (_target == null)
            throw new ServletException("you did not specify a target parameter");

        _source = config.getInitParameter("source");
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        GetMethod method = new GetMethod(proxyUrl(req));
        executeMethod(method, resp);
    }

    /****
     * Private Method
     ****/

    private String proxyUrl(HttpServletRequest req) {

        String pathInfo = req.getRequestURI();

        if (_source != null)
            pathInfo = pathInfo.replaceFirst(_source, "");

        String url = _target + pathInfo;

        if (!_target.startsWith("http"))
            url = "http://" + req.getLocalName() + ":" + req.getLocalPort() + url;

        if (req.getQueryString() != null)
            url += "?" + req.getQueryString();
        return url;
    }

    private void executeMethod(HttpMethod method, HttpServletResponse resp) throws ServletException, IOException {

        HttpClient client = new HttpClient();

        int status = client.executeMethod(method);

        resp.setStatus(status);

        // Pass response headers back to the client
        Header[] headerArrayResponse = method.getResponseHeaders();
        for (Header header : headerArrayResponse)
            resp.setHeader(header.getName(), header.getValue());

        // Send the content to the client
        InputStream in = method.getResponseBodyAsStream();
        OutputStream out = resp.getOutputStream();

        byte[] buffer = new byte[1024];
        int rc;
        while ((rc = in.read(buffer)) != -1)
            out.write(buffer, 0, rc);
    }
}