/* * Copyright 2002-2005 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.jencks.interceptor;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.apache.geronimo.transaction.DefaultInstanceContext;import org.apache.geronimo.transaction.InstanceContext;import org.apache.geronimo.transaction.TrackedConnectionAssociator;import javax.resource.ResourceException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import java.io.IOException;import java.util.HashSet;import java.util.Set;/** * This servlet filter is used to enter in a transactional context * automtically at every servlet call and exit of it when the response * is sent back to the client. * <p/> * This class must be used with a mechanism (for example, Acegi) to * use injection on filters. * <p/> * The following is an example of use: * <p/> * <web-app id="WebApp"> * ... * <filter> * <filter-name>Geronimo Transaction Context Filter</filter-name> * <filter-class> * org.springframework.web.filter.DelegatingFilterProxy</filter-class> * <init-param> * <param-name>targetBeanName</param-name> * <param-value> * org.springframework.jca.interceptor.TransactionContexFilter * </param-value> * </init-param> * </filter> * <p/> * <filter-mapping> * <filter-name>Geronimo Transaction Context Filter</filter-name> * <url-pattern>/*</url-pattern> * </filter-mapping> * ... * </web-app> * * @author Thierry Templier * @see TrackedConnectionAssociator#enter(InstanceContext) * @see TrackedConnectionAssociator#exit(InstanceContext) * @see InstanceContext * @see DefaultInstanceContext */public class TransactionContexFilter implements Filter {    private TrackedConnectionAssociator associator;    protected transient Log logger = LogFactory.getLog(getClass());    public void init(FilterConfig config) throws ServletException {    }    /**     * This is the central method of the filter which allows the     * request to enter in a transactionnal context and exit when     * the request is sent back to the client.     *     * @see #enterContext(Set, Set)     * @see #exitContext(InstanceContext)     */    public void doFilter(ServletRequest request, ServletResponse response,                         FilterChain chain) throws IOException, ServletException {        // Enter in the transactionnal context        Set unshareableResources = new HashSet();        Set applicationManagedSecurityResources = new HashSet();        InstanceContext oldContext =                enterContext(unshareableResources, applicationManagedSecurityResources);        // Proceed with chain        chain.doFilter(request, response);        // Exit the transactionnal context        exitContext(oldContext);    }    /**     * This method enters in a new context and returns it     * in order to exit of it when the request is sent back to     * the client.     */    private InstanceContext enterContext(Set unshareableResources,                                         Set applicationManagedSecurityResources) {        try {            InstanceContext oldContext =                    associator.enter(new DefaultInstanceContext(                            unshareableResources, applicationManagedSecurityResources));            if (logger.isDebugEnabled()) {                logger.info("Geronimo transaction context set.");            }            return oldContext;        }        catch (ResourceException ex) {        }        return null;    }    /**     * This method exits of the specified context. This context is     * created when entering a new one.     *     * @see #enterContext(Set, Set)     */    private void exitContext(InstanceContext oldContext) {        try {            associator.exit(oldContext);            if (logger.isDebugEnabled()) {                logger.info("Geronimo transaction context unset.");            }        }        catch (ResourceException ex) {        }    }    public void destroy() {    }    /**     * Set the TrackedConnectionAssociator instance to allow the bean     * to enter and exit a transactional context.     */    public void setAssociator(TrackedConnectionAssociator associator) {        this.associator = associator;	}}