--- /dev/null
+/*
+ * Copyright 2005-2010 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.wamblee.wicket.transactions;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import javax.transaction.Status;
+import javax.transaction.UserTransaction;
+
+import org.apache.wicket.Application;
+import org.apache.wicket.Page;
+import org.apache.wicket.Response;
+import org.apache.wicket.protocol.http.WebApplication;
+import org.apache.wicket.protocol.http.WebRequest;
+import org.apache.wicket.protocol.http.WebRequestCycle;
+
+/**
+ * <p>
+ * This class provides an <em>Open Transaction in View</em> implementation for
+ * wicket. It provides a custom request cycle that uses the
+ * {@link UserTransaction} to make sure that all work is done within a single
+ * transaction. In hibernate context, this is referred to as open session in
+ * view.
+ * </p>
+ *
+ * <p>
+ * The method used by this class is more correctly called
+ * <em>Open Transaction in View</em> and has a similar effect to open session in
+ * view. It is however more general because it supports any (JTA) transactional
+ * resource. Also it is more efficient/scalable than most open session in view
+ * implementations because a database connection is only obtained from the
+ * connection pool when it is needed.
+ * </p>
+ *
+ * <p>
+ * To use this request cycle, add it in your wicket {@link Application} subclass
+ * by overriding
+ * {@link Application#newRequestCycle(org.apache.wicket.Request, Response)}. For
+ * example:
+ * </p>
+ *
+ * <pre>
+ * @Override
+ * public RequestCycle newRequestCycle(Request aRequest, Response aResponse) {
+ * return new OpenTransactionInViewRequestCycle(this, (WebRequest) aRequest,
+ * aResponse);
+ * }
+ * </pre>
+ *
+ * @author Erik Brakkee
+ *
+ */
+public class OpenTransactionInViewRequestCycle extends WebRequestCycle {
+
+ private static final Logger LOG = Logger.getLogger(OpenTransactionInViewRequestCycle.class.getName());
+
+ private static final String JAVA_COMP_USER_TRANSACTION_JNDI = "java:comp/UserTransaction";
+ private UserTransaction userTransaction;
+
+ /**
+ * Constructs the request cycle.
+ *
+ * @param aApplication
+ * Application to use.
+ * @param aRequest
+ * Request
+ * @param aResponse
+ * Response.
+ */
+ public OpenTransactionInViewRequestCycle(final WebApplication aApplication,
+ final WebRequest aRequest, final Response aResponse) {
+ super(aApplication, aRequest, aResponse);
+ userTransaction = getUserTransaction();
+ }
+
+ @Override
+ protected void onBeginRequest() {
+ try {
+ userTransaction.begin();
+ } catch (Exception e) {
+ throw new RuntimeException("Could not start transaction", e);
+ }
+ super.onBeginRequest();
+ }
+
+ @Override
+ protected void onEndRequest() {
+ try {
+ if ( LOG.isLoggable(Level.FINEST)) {
+ LOG.finest("Transaction status: " + userTransaction.getStatus());
+ }
+ if (userTransaction.getStatus() == Status.STATUS_ACTIVE) {
+ userTransaction.commit();
+ } else if (userTransaction.getStatus() == Status.STATUS_MARKED_ROLLBACK) {
+ userTransaction.rollback();
+ } else {
+ LOG.warning("Transaction status is '" + userTransaction.getStatus() + "' not committing or rolling back");
+ }
+ } catch (Exception e) {
+ throw new RuntimeException("Could not commit transaction", e);
+ }
+ super.onEndRequest();
+ }
+
+ @Override
+ public Page onRuntimeException(Page aPage, RuntimeException aE) {
+ super.onEndRequest();
+ try {
+ userTransaction.rollback();
+ } catch (Exception e) {
+ throw new RuntimeException("Could not rollback transaction", e);
+ }
+ return super.onRuntimeException(aPage, aE);
+ }
+
+ private UserTransaction getUserTransaction() {
+ try {
+ InitialContext ctx = new InitialContext();
+ return (UserTransaction) ctx
+ .lookup(JAVA_COMP_USER_TRANSACTION_JNDI);
+ } catch (NamingException e) {
+ throw new RuntimeException(
+ "Could not obtain user transaction object");
+ }
+ }
+}