mobi.jenkinsci.server.core.servlet.HttpRequestDispatcherServlet.java Source code

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Here is the source code for mobi.jenkinsci.server.core.servlet.HttpRequestDispatcherServlet.java

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// Copyright (C) 2013 GerritForge www.gerritforge.com
//
// 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 mobi.jenkinsci.server.core.servlet;

import java.io.IOException;
import java.util.Map;

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

import com.google.common.collect.Maps;
import com.google.inject.Singleton;
import lombok.extern.slf4j.Slf4j;
import mobi.jenkinsci.commons.Account;
import mobi.jenkinsci.exceptions.ResourceNotFoundException;
import mobi.jenkinsci.model.AbstractNode;
import mobi.jenkinsci.model.NotModifiedNode;
import mobi.jenkinsci.model.ResetNode;
import mobi.jenkinsci.server.core.services.ProxyHttpClientURLDownloader;
import mobi.jenkinsci.server.core.services.RequestCommandDispatcher;

import org.apache.http.HttpStatus;

import com.google.gson.Gson;
import com.google.inject.Inject;

@Slf4j
@Singleton
public class HttpRequestDispatcherServlet extends HttpServlet {
    private static final long serialVersionUID = -1149567900063915796L;

    private final RequestCommandDispatcher pluginRequestDispatcher;

    private final ProxyHttpClientURLDownloader resourcePlugin;

    private final Gson gson;

    private Map<Class<? extends AbstractNode>, Integer> errorStatusMap;

    @Inject
    public HttpRequestDispatcherServlet(final RequestCommandDispatcher pluginRequestDispatcher,
            final ProxyHttpClientURLDownloader resourcePlugin, final Gson gson) {
        super();
        this.pluginRequestDispatcher = pluginRequestDispatcher;
        this.resourcePlugin = resourcePlugin;
        this.gson = gson;
    }

    @Override
    public void init(final ServletConfig config) throws ServletException {
        errorStatusMap = Maps.newHashMap();
        errorStatusMap.put(NotModifiedNode.class, HttpStatus.SC_NOT_MODIFIED);
        errorStatusMap.put(ResetNode.class, HttpStatus.SC_RESET_CONTENT);
    }

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

        try {
            final Account account = (Account) req.getUserPrincipal();

            final AbstractNode responseTree = pluginRequestDispatcher.getResponse(account, req);
            final String eTag = responseTree.getETag();
            final String reqETag = req.getHeader("If-None-Match");

            final Integer errorResponseStatus = errorStatusMap.get(responseTree.getClass());

            // Error response
            if (errorResponseStatus != null) {
                resp.sendError(errorResponseStatus);
            }

            // Cached response
            else if (reqETag != null && eTag != null && reqETag.equals(eTag)) {
                resp.setStatus(HttpStatus.SC_NOT_MODIFIED);
                log.debug("Resource " + req.getRequestURI() + " was NOT MODIFIED: returning HTTP-304");
            }

            // JSON response
            else {
                setResponseHeaders(resp, responseTree);
                resp.setHeader("Content-Type", "application/json");
                responseTree.toStream(resp.getOutputStream());
            }
        } catch (final ResourceNotFoundException e) {
            resp.sendError(HttpStatus.SC_NOT_FOUND);
        } catch (final Exception e) {
            throw new ServletException(e);
        }
    }

    private void setResponseHeaders(final HttpServletResponse resp, final AbstractNode responseTree) {
        if (!responseTree.isCacheable()) {
            resp.setHeader("Cache-Control", "no-cache");
        }
        final String eTag = responseTree.getETag();
        if (eTag != null) {
            resp.setHeader("ETag", eTag);
        }
        if (responseTree.getHttpCharacterEncoding() != null) {
            resp.setCharacterEncoding(responseTree.getHttpCharacterEncoding());
        }
    }
}