com.enonic.cms.server.service.servlet.CmsDispatcherServlet.java Source code

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Here is the source code for com.enonic.cms.server.service.servlet.CmsDispatcherServlet.java

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/*
 * Copyright 2000-2011 Enonic AS
 * http://www.enonic.com/license
 */
package com.enonic.cms.server.service.servlet;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;

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

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.http.HttpMethod;
import org.springframework.web.context.ConfigurableWebApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.servlet.DispatcherServlet;

import com.enonic.cms.core.servlet.ServletRequestAccessor;
import com.enonic.cms.server.service.upgrade.UpgradeCheckerHelper;

import com.enonic.cms.domain.Attribute;

/**
 * This class implements a modification of the dispatcher servlet.
 */
public final class CmsDispatcherServlet extends DispatcherServlet {
    private static final Logger LOG = LoggerFactory.getLogger(CmsDispatcherServlet.class);

    private final static List<HttpMethod> ALLOWED_HTTP_METHODS = Arrays.asList(HttpMethod.GET, HttpMethod.POST,
            HttpMethod.HEAD, HttpMethod.OPTIONS);

    /**
     * Upgrade check parameter.
     */
    private final static String UPGRADE_CHECK_PARAM = "upgradeCheck";

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        startContextIfNeeded();
    }

    @Override
    protected void doOptions(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setHeader("Allow", StringUtils.join(ALLOWED_HTTP_METHODS, ","));
        response.setStatus(HttpServletResponse.SC_OK);
    }

    protected void doService(HttpServletRequest req, HttpServletResponse res) throws Exception {

        HttpMethod requestMethod = HttpMethod.valueOf(req.getMethod());

        if (!ALLOWED_HTTP_METHODS.contains(requestMethod)) {
            res.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
            return;
        }

        startContextIfNeeded();
        if (upgradeIsNeeded(res)) {
            return;
        }

        ServletRequestAccessor.setRequest(req);
        // resolve and set original url if not set
        if (req.getAttribute(Attribute.ORIGINAL_URL) == null) {
            final String originalUrl = OriginalUrlResolver.get().resolveOriginalUrl(req);
            req.setAttribute(Attribute.ORIGINAL_URL, originalUrl);
        }

        if (LOG.isDebugEnabled()) {
            StringBuffer msg = new StringBuffer();
            msg.append("Dispatching request to URL: " + req.getRequestURL());
            LOG.debug(msg.toString());
        }

        super.doService(req, res);
    }

    private boolean upgradeIsNeeded(HttpServletResponse res) throws Exception {
        return "true".equals(getInitParameter(UPGRADE_CHECK_PARAM))
                && UpgradeCheckerHelper.checkUpgrade(getServletContext(), res);
    }

    private ApplicationContext startContextIfNeeded() {
        WebApplicationContext appContext = WebApplicationContextUtils
                .getRequiredWebApplicationContext(getServletContext());
        if (appContext instanceof ConfigurableWebApplicationContext) {
            startContextIfNeeded((ConfigurableWebApplicationContext) appContext);
        }
        return appContext;
    }

    private static void startContextIfNeeded(ConfigurableWebApplicationContext context) {
        if (!context.isRunning()) {
            context.start();
        }
    }

}