org.spring4gwt.server.SpringGwtRemoteServiceServlet.java Source code

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Here is the source code for org.spring4gwt.server.SpringGwtRemoteServiceServlet.java

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/**
 *  Copyright 2014-2016 CyberVision, Inc.
 *
 *  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.spring4gwt.server;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException;
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.server.rpc.RPC;
import com.google.gwt.user.server.rpc.RPCRequest;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;

@SuppressWarnings("serial")
public class SpringGwtRemoteServiceServlet extends RemoteServiceServlet {

    /** The Constant logger. */
    private static final Logger logger = LoggerFactory.getLogger(SpringGwtRemoteServiceServlet.class);

    static ThreadLocal<HttpServletRequest> perThreadRequest = new ThreadLocal<HttpServletRequest>();

    @Override
    public void init() {
        if (logger.isDebugEnabled()) {
            logger.debug("Spring GWT service exporter deployed");
        }
    }

    @Override
    public String processCall(String payload) throws SerializationException {
        try {
            perThreadRequest.set(getThreadLocalRequest());
            Object handler = getBean(getThreadLocalRequest());
            RPCRequest rpcRequest = RPC.decodeRequest(payload, handler.getClass(), this);
            onAfterRequestDeserialized(rpcRequest);
            if (logger.isDebugEnabled()) {
                logger.debug("Invoking " + handler.getClass().getName() + "." + rpcRequest.getMethod().getName());
            }
            return RPCHelper.invokeAndEncodeResponse(handler, rpcRequest.getMethod(), rpcRequest.getParameters(),
                    rpcRequest.getSerializationPolicy());
        } catch (IncompatibleRemoteServiceException ex) {
            log("An IncompatibleRemoteServiceException was thrown while processing this call.", ex);
            return RPC.encodeResponseForFailure(null, ex);
        } catch (SerializationException ex) {
            logger.error("An SerializationException was thrown while processing this call.", ex);
            throw ex;
        } finally {
            perThreadRequest.set(null);
        }
    }

    public static HttpServletRequest getRequest() {
        return perThreadRequest.get();
    }

    public static void setRequest(HttpServletRequest request) {
        perThreadRequest.set(request);
    }

    /**
     * Determine Spring bean to handle request based on request URL, e.g. a
     * request ending in /myService will be handled by bean with name
     * "myService".
     * 
     * @param request
     * @return handler bean
     */
    protected Object getBean(HttpServletRequest request) {
        String service = getService(request);
        Object bean = getBean(service);
        if (!(bean instanceof RemoteService)) {
            throw new IllegalArgumentException(
                    "Spring bean is not a GWT RemoteService: " + service + " (" + bean + ")");
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Bean for service " + service + " is " + bean);
        }
        return bean;
    }

    /**
     * Parse the service name from the request URL.
     * 
     * @param request
     * @return bean name
     */
    protected String getService(HttpServletRequest request) {
        String url = request.getRequestURI();
        String service = url.substring(url.lastIndexOf("/") + 1);
        if (logger.isDebugEnabled()) {
            logger.debug("Service for URL {} is {}", url, service);
        }
        return service;
    }

    /**
     * Look up a spring bean with the specified name in the current web
     * application context.
     * 
     * @param name
     *            bean name
     * @return the bean
     */
    protected Object getBean(String name) {
        WebApplicationContext applicationContext = WebApplicationContextUtils
                .getWebApplicationContext(getServletContext());
        if (applicationContext == null) {
            throw new IllegalStateException("No Spring web application context found");
        }
        if (!applicationContext.containsBean(name)) {
            {
                throw new IllegalArgumentException("Spring bean not found: " + name);
            }
        }
        return applicationContext.getBean(name);
    }
}