io.neba.core.mvc.MvcServlet Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of io.neba.neba-core Show documentation
Contains the entire NEBA core implementation, i.e. the framework that interprets the NEBA API annotations and provides implementations for the service and lifecycle callback interfaces provided in the NEBA API. This package must not export anything as its implementation details are entirely private.
There is a newer version: 5.2.3
Show newest version
/**
 * Copyright 2013 the original author or authors.
 * 
 * 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 io.neba.core.mvc;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Service;

import javax.servlet.ServletException;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;

/**
 * Dispatches controller requests to the bundle-specific {@link MvcContext mvc contexts}. The first
 * {@link MvcContext#isResponsibleFor(javax.servlet.http.HttpServletRequest) responsible} context wins.
 * If no context is responsible, a 404 response is returned.

 * {@link #enableMvc(org.springframework.beans.factory.config.ConfigurableListableBeanFactory, org.osgi.framework.BundleContext) Enables}
 * and {@link #disableMvc(org.osgi.framework.Bundle) disables} MVC capabilities in bundles
 * via the injection of the {@link MvcContext} into the {@link ConfigurableListableBeanFactory bean factories}
 * of the bundles.
 *
 * @see MvcContext
 *
 * @author Olaf Otto
 */
@Service
public class MvcServlet extends SlingAllMethodsServlet {
    private static final String MVC_ENABLER_BEAN_NAME = "_nebaMvcEnabler";
    private final Map mvcCapableBundles = new ConcurrentHashMap();
    private final Logger logger = LoggerFactory.getLogger("mvc");

    /**
     * Enables MVC capabilities in the given factory by injecting a {@link MvcContext} singleton.
     *
     * @param factory must not be null.
     * @param context must not be null.
     */
    public void enableMvc(ConfigurableListableBeanFactory factory, BundleContext context) {
        if (factory == null) {
            throw new IllegalArgumentException("Method argument factory must not be null.");
        }
        if (context == null) {
            throw new IllegalArgumentException("Method argument context must not be null.");
        }

        final MvcContext mvcContext = createMvcContext(factory);
        factory.registerSingleton(MVC_ENABLER_BEAN_NAME, mvcContext);
        this.mvcCapableBundles.put(context.getBundle(), mvcContext);
    }


    /**
     * Removes the {@link MvcContext} associated with the given bundle, if any.
     *
     * @param bundle must not be null.
     */
    public void disableMvc(Bundle bundle) {
        if (bundle == null) {
            throw new IllegalArgumentException("Method argument bundle must not be null.");
        }
        this.mvcCapableBundles.remove(bundle);
    }

    @Override
    protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doPut(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doDelete(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doHead(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doOptions(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    @Override
    protected void doTrace(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        handle(request, response);
    }

    protected void handle(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
        final SlingMvcServletRequest slingRequest = new SlingMvcServletRequest(request);

        MvcContext context = lookupResponsible(slingRequest);
        if (context != null) {
            context.service(slingRequest, response);
        } else {
            if (this.logger.isDebugEnabled()) {
                this.logger.debug("No controller found for request " + request + ".");
            }
            response.sendError(SC_NOT_FOUND);
        }
    }

    protected MvcContext createMvcContext(ConfigurableListableBeanFactory factory) {
        return new MvcContext(factory);
    }

    private MvcContext lookupResponsible(SlingHttpServletRequest request) {
        for (MvcContext context : this.mvcCapableBundles.values()) {
            if (context.mustInitializeDispatcherServlet()) {
                context.initializeDispatcherServlet(getServletConfig());
            }
            if (context.isResponsibleFor(request)) {
                return context;
            }
        }
        return null;
    }
}