org.impalaframework.web.servlet.invoker.ServletInvokerUtils.java Source code

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Here is the source code for org.impalaframework.web.servlet.invoker.ServletInvokerUtils.java

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/*
 * Copyright 2007-2010 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 org.impalaframework.web.servlet.invoker;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.impalaframework.module.spi.FrameworkLockHolder;
import org.springframework.web.context.WebApplicationContext;

public class ServletInvokerUtils {

    private static Log logger = LogFactory.getLog(ServletInvokerUtils.class);

    /**
     * Used to invoke either the <code>HttpServiceInvoker.invoke</code> or <code>HttpServlet.service</code>, depending on the class of target.
     * In both cases, the request and response are passed through.
     * 
     * @param target either an instance of <code>HttpServiceInvoker</code> or <code>HttpServlet</code>.
     * @param filterChain instanceof <code>FilterChain</code>. Applies only if target is instance of <code>Filter</code>
     */
    public static void invoke(Object target, HttpServletRequest request, HttpServletResponse response,
            FilterChain filterChain) throws ServletException, IOException {

        if (target instanceof HttpServiceInvoker) {
            HttpServiceInvoker invoker = (HttpServiceInvoker) target;
            invoker.invoke(request, response, null);
        } else if (target instanceof Servlet) {
            Servlet servlet = (Servlet) target;
            servlet.service(request, response);
        } else if (target instanceof Filter) {
            Filter filter = (Filter) target;
            filter.doFilter(request, response, filterChain);
        } else {
            logger.warn("invoke called with target " + (target != null) + " which is not an instance of "
                    + HttpServiceInvoker.class.getSimpleName() + ", " + HttpServlet.class.getSimpleName() + " or "
                    + Filter.class.getName());
        }

    }

    public static ReadWriteLockingInvoker getHttpServiceInvoker(Servlet delegateServlet, WebApplicationContext wac,
            FrameworkLockHolder frameworkLockHolder, boolean setThreadContextClassLoader) {

        Object toWrap = null;

        if (setThreadContextClassLoader) {
            ClassLoader moduleClassLoader = wac.getClassLoader();
            ThreadContextClassLoaderHttpServiceInvoker classLoaderInvoker = new ThreadContextClassLoaderHttpServiceInvoker(
                    delegateServlet, true, moduleClassLoader);
            toWrap = classLoaderInvoker;
        } else {
            toWrap = delegateServlet;
        }
        return new ReadWriteLockingInvoker(toWrap, frameworkLockHolder);

    }
}