de.itsvs.cwtrpc.security.AbstractRpcFailureHandler.java Source code

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Here is the source code for de.itsvs.cwtrpc.security.AbstractRpcFailureHandler.java

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/*
 *  Copyright 2011 IT Services VS GmbH
 *
 *  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 de.itsvs.cwtrpc.security;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;
import org.springframework.web.context.ServletContextAware;

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.RPCServletUtils;
import com.google.gwt.user.server.rpc.UnexpectedException;

import de.itsvs.cwtrpc.core.CwtRpcUtils;

/**
 * @author Volker Schmidt
 * @since 0.9
 */
public abstract class AbstractRpcFailureHandler implements ServletContextAware, InitializingBean {
    private final Log log = LogFactory.getLog(AbstractRpcFailureHandler.class);

    private ServletContext servletContext;

    public ServletContext getServletContext() {
        return servletContext;
    }

    public void setServletContext(ServletContext servletContext) {
        this.servletContext = servletContext;
    }

    public void afterPropertiesSet() {
        Assert.notNull(getServletContext(), "servletContext must be specified");
    }

    protected void writeUnexpectedException(HttpServletRequest request, HttpServletResponse response,
            Throwable exception) throws IOException {
        if (CwtRpcUtils.getRpcSessionInvalidationPolicy(request).isInvalidateOnUnexpectedException()) {
            invalidateSession(request);
        }

        response.reset();
        addNoCacheResponseHeaders(request, response);
        RPCServletUtils.writeResponseForUnexpectedFailure(getServletContext(), response, exception);
        response.flushBuffer();
    }

    protected void writeExpectedException(HttpServletRequest request, HttpServletResponse response,
            Exception remoteException) throws IOException {
        final RPCRequest rpcRequest;
        final String responsePayload;

        rpcRequest = AbstractRpcAuthenticationProcessingFilter.getRpcRequest(request);
        try {
            if (rpcRequest != null) {
                /* checked exceptions must be declared by service method */
                responsePayload = RPC.encodeResponseForFailure(rpcRequest.getMethod(), remoteException,
                        rpcRequest.getSerializationPolicy());
            } else {
                log.warn("Could not determine RPC request. Using default serialization.");
                responsePayload = RPC.encodeResponseForFailure(null, remoteException);
            }
        } catch (UnexpectedException e) {
            if (rpcRequest != null) {
                log.error("Exception " + remoteException.getClass().getName() + " is unexpected for method "
                        + rpcRequest.getMethod() + " of declaring class "
                        + rpcRequest.getMethod().getDeclaringClass().getName(), e);
            } else {
                log.error("Exception " + remoteException.getClass().getName() + " is unexpected for unknown method",
                        e);
            }
            writeUnexpectedException(request, response, remoteException);
            return;
        } catch (SerializationException e) {
            log.error("Error while serializing " + remoteException.getClass().getName(), e);
            writeUnexpectedException(request, response, remoteException);
            return;
        }

        if (CwtRpcUtils.getRpcSessionInvalidationPolicy(request).isInvalidateOnExpectedException()) {
            invalidateSession(request);
        }

        response.reset();
        addNoCacheResponseHeaders(request, response);
        RPCServletUtils.writeResponse(getServletContext(), response, responsePayload, false);
        response.flushBuffer();
    }

    protected void invalidateSession(HttpServletRequest request) {
        final HttpSession session;

        session = request.getSession(false);
        if (session != null) {
            if (log.isDebugEnabled()) {
                log.debug("Invalidating session " + session.getId());
            }
            session.invalidate();
        }
    }

    protected void addNoCacheResponseHeaders(HttpServletRequest request, HttpServletResponse response) {
        CwtRpcUtils.addNoCacheResponseHeaders(request, response);
    }
}