org.sakaiproject.kernel.webapp.RestServlet.java Source code

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Here is the source code for org.sakaiproject.kernel.webapp.RestServlet.java

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/*
 * Licensed to the Sakai Foundation (SF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The SF licenses this file
 * to you 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.sakaiproject.kernel.webapp;

import org.apache.commons.lang.StringUtils;
import org.sakaiproject.kernel.api.KernelManager;
import org.sakaiproject.kernel.api.Registry;
import org.sakaiproject.kernel.api.RegistryService;
import org.sakaiproject.kernel.api.rest.RestProvider;
import org.sakaiproject.kernel.util.rest.RestDescription;

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;

/**
 *
 */
public class RestServlet extends HttpServlet {

    /**
     *
     */
    private static final long serialVersionUID = -172232497404083238L;
    private transient Registry<String, RestProvider> registry;

    /**
     * {@inheritDoc}
     *
     * @see javax.servlet.GenericServlet#init(javax.servlet.ServletConfig)
     */
    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        KernelManager km = new KernelManager();
        RegistryService registryService = km.getService(RegistryService.class);
        registry = registryService.getRegistry(RestProvider.REST_REGISTRY);
    }

    /**
     * {@inheritDoc}
     *
     * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
     *      javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String requestPath = request.getPathInfo();
        if (requestPath == null) {
            requestPath = "";
        }
        String[] elements = StringUtils.split(requestPath, '/');
        String locator = "default";
        if (elements != null && elements.length > 0) {
            locator = elements[0];
        }
        Map<String, RestProvider> restProviders = registry.getMap();
        if (locator == null) {
            locator = "default";
        }
        if ("__describe__".equals(locator)) {
            locator = "default";
        }
        RestProvider restProvider = restProviders.get(locator);
        if (restProvider == null) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
        } else {
            try {
                if (requestPath.endsWith("__describe__")) {
                    RestDescription description = restProvider.getDescription();
                    String format = request.getParameter("fmt");
                    if ("xml".equals(format)) {
                        response.setContentType("text/xml");
                        response.getWriter().print(description.toXml());
                    } else if ("json".equals(format)) {
                        response.setContentType(RestProvider.CONTENT_TYPE);
                        response.getWriter().print(description.toJson());
                    } else {
                        response.setContentType("text/html");
                        response.getWriter().print(description.toHtml());
                    }
                } else {
                    restProvider.dispatch(elements, request, response);
                }
            } catch (SecurityException ex) {
                response.reset();
                response.sendError(HttpServletResponse.SC_FORBIDDEN, ex.getMessage());
            } catch (RestServiceFaultException ex) {
                ex.printStackTrace();
                response.reset();
                response.sendError(ex.getStatusCode(), ex.getMessage());
            }
        }
    }
}