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updated to use flow scope

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This commit is contained in:
Keith Donald
2007-08-09 14:37:53 +00:00
parent 0b5e401de2
commit 10e8eb4657
4 changed files with 97 additions and 35 deletions
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49
spring-webflow/src/main/java/org/springframework/webflow/support/persistence/HibernateFlowExecutionListener.java
View File

@@ -26,6 +26,7 @@ import org.springframework.transaction.support.TransactionCallbackWithoutResult;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.transaction.support.TransactionTemplate;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.definition.FlowDefinition;
import org.springframework.webflow.execution.FlowExecutionException;
import org.springframework.webflow.execution.FlowExecutionListener;
import org.springframework.webflow.execution.FlowExecutionListenerAdapter;
@@ -34,11 +35,12 @@ import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.ViewSelection;
/**
* A {@link FlowExecutionListener} that implements the Session-per-Conversation pattern using the native Hibernate API.
* A {@link FlowExecutionListener} that implements the Flow Managed Persistence Context (FMPC) pattern using the native
* Hibernate API.
* <p>
* The general pattern is as follows:
* <ul>
* <li>When a flow execution starts, create a new Hibernate Session and bind it to conversation scope.
* <li>When a flow execution starts, create a new Hibernate Session and bind it to flow scope.
* <li>Before processing a flow execution request, expose the conversationally-bound session as the "current session"
* for the current thread.
* <li>When an existing flow pauses, unbind the session from the current thread.
@@ -50,8 +52,8 @@ import org.springframework.webflow.execution.ViewSelection;
* <ul>
* <li> Create a new persistence context when a new flow execution with the 'persistenceContext' attribute starts
* <li> Load some objects into this persistence context
* <li> Perform edits to those objects over a series of conversational requests
* <li> On successful conversation completion, commit and flush those edits to the database, applying a version check if
* <li> Perform edits to those objects over a series of requests into the flow
* <li> On successful flow ccompletion, commit and flush those edits to the database, applying a version check if
* necessary.
* </ul>
*
@@ -61,10 +63,10 @@ import org.springframework.webflow.execution.ViewSelection;
* transaction. In that case, the session's flush mode will be set to Manual and no intermediate changes will be
* flushed.
* <p>
* Care should be taken to prevent premature commits of conversational data while the conversation is in progress. You
* would generally not want intermediate flushing to happen, as the nature of a conversation implies a transient,
* isolated resource that can be canceled before it ends. Generally, the only time a read-write transaction should be
* started is upon successful completion of the conversation, triggered by reaching a 'commit' end state.
* Care should be taken to prevent premature commits of flow data while the flow is in progress. You would generally not
* want intermediate flushing to happen, as the nature of a flow implies a transient, isolated resource that can be
* canceled before it ends. Generally, the only time a read-write transaction should be started is upon successful
* completion of the conversation, triggered by reaching a 'commit' end state.
*
* @author Ben Hale
* @author Keith Donald
@@ -73,6 +75,8 @@ import org.springframework.webflow.execution.ViewSelection;
*/
public class HibernateFlowExecutionListener extends FlowExecutionListenerAdapter {
private static final String PERSISTENCE_CONTEXT_ATTRIBUTE = "persistenceContext";
private static final String HIBERNATE_SESSION_ATTRIBUTE = "session";
private TransactionTemplate transactionTemplate;
@@ -99,25 +103,28 @@ public class HibernateFlowExecutionListener extends FlowExecutionListenerAdapter
}
public void sessionCreated(RequestContext context, FlowSession session) {
if (session.isRoot() && session.getDefinition().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(session.getDefinition())) {
Session hibernateSession = createSession(context);
context.getConversationScope().put(HIBERNATE_SESSION_ATTRIBUTE, hibernateSession);
session.getScope().put(HIBERNATE_SESSION_ATTRIBUTE, hibernateSession);
bind(hibernateSession, context);
}
}
public void resumed(RequestContext context) {
bind(getHibernateSession(context), context);
if (isPersistenceContext(context.getActiveFlow())) {
bind(getHibernateSession(context), context);
}
}
public void paused(RequestContext context, ViewSelection selectedView) {
unbind(getHibernateSession(context), context);
if (isPersistenceContext(context.getActiveFlow())) {
unbind(getHibernateSession(context), context);
}
}
public void sessionEnded(RequestContext context, FlowSession session, AttributeMap output) {
if (session.isRoot()) {
final Session hibernateSession = (Session) context.getConversationScope().remove(
HIBERNATE_SESSION_ATTRIBUTE);
if (isPersistenceContext(session.getDefinition())) {
final Session hibernateSession = (Session) session.getScope().remove(HIBERNATE_SESSION_ATTRIBUTE);
Boolean commitStatus = session.getState().getAttributes().getBoolean("commit");
if (Boolean.TRUE.equals(commitStatus)) {
// this is a commit end state - start a new transaction that quickly commits
@@ -129,17 +136,23 @@ public class HibernateFlowExecutionListener extends FlowExecutionListenerAdapter
}
});
}
hibernateSession.close();
unbind(hibernateSession, context);
hibernateSession.close();
}
}
public void exceptionThrown(RequestContext context, FlowExecutionException exception) {
unbind(getHibernateSession(context), context);
if (isPersistenceContext(context.getActiveFlow())) {
unbind(getHibernateSession(context), context);
}
}
// internal helpers
private boolean isPersistenceContext(FlowDefinition flow) {
return flow.getAttributes().contains(PERSISTENCE_CONTEXT_ATTRIBUTE);
}
private Session createSession(RequestContext context) {
Session session = (entityInterceptor != null ? sessionFactory.openSession(entityInterceptor) : sessionFactory
.openSession());
@@ -148,7 +161,7 @@ public class HibernateFlowExecutionListener extends FlowExecutionListenerAdapter
}
private Session getHibernateSession(RequestContext context) {
return (Session) context.getConversationScope().get(HIBERNATE_SESSION_ATTRIBUTE);
return (Session) context.getFlowScope().get(HIBERNATE_SESSION_ATTRIBUTE);
}
private void bind(Session session, RequestContext context) {

39
spring-webflow/src/main/java/org/springframework/webflow/support/persistence/JpaFlowExecutionListener.java
View File

@@ -25,6 +25,7 @@ import org.springframework.transaction.support.TransactionCallbackWithoutResult;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.transaction.support.TransactionTemplate;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.definition.FlowDefinition;
import org.springframework.webflow.execution.FlowExecutionException;
import org.springframework.webflow.execution.FlowExecutionListener;
import org.springframework.webflow.execution.FlowExecutionListenerAdapter;
@@ -33,14 +34,14 @@ import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.ViewSelection;
/**
* A {@link FlowExecutionListener} that implements the Session-per-Conversation using the standard Java Persistence API
* (JPA).
* A {@link FlowExecutionListener} that implements the Flow Managed Persistence Context (FMPC) pattern using the
* standard Java Persistence API (JPA).
* <p>
* This implementation uses standard JPA APIs. The general pattern is as follows:
* <ul>
* <li>When a flow execution starts, create a new JPA persistence context and bind it to conversation scope.
* <li>Before processing a flow execution request, expose the conversationally-bound persistence context as the
* "current" persistence context for the current thread.
* <li>When a flow execution starts, create a new JPA persistence context and bind it to flow scope.
* <li>Before processing a flow execution request, expose the flow-scoped persistence context as the "current"
* persistence context for the current thread.
* <li>When an existing flow pauses, unbind the persistence context from the current thread.
* <li>When an existing flow ends, commit the changes made to the persistence context in a transaction if the ending
* state is a commit state. Then, unbind the context and close it.
@@ -50,7 +51,7 @@ import org.springframework.webflow.execution.ViewSelection;
* <ul>
* <li> Create a new persistence context when a new flow execution with the 'persistenceContext' attribute starts
* <li> Load some objects into this persistence context
* <li> Perform edits to those objects over a series of conversational requests
* <li> Perform edits to those objects over a series of requests into the flow
* <li> On successful conversation completion, commit and flush those edits to the database, applying a version check if
* necessary.
* </ul>
@@ -63,10 +64,10 @@ import org.springframework.webflow.execution.ViewSelection;
* to MANUAL to ensure any in-progress changes to managed persistent entities are not flushed, while reads of new
* objects occur transactionally.
* <p>
* Care should be taken to prevent premature commits of conversational data while the conversation is in progress. You
* would generally not want intermediate flushing to happen, as the nature of a conversation implies a transient,
* isolated resource that can be canceled before it ends. Generally, the only time a read-write transaction should be
* started is upon successful completion of the conversation, triggered by reaching a 'commit' end state.
* Care should be taken to prevent premature commits of flow data while the flow is in progress. You would generally not
* want intermediate flushing to happen, as the nature of a flow implies a transient, isolated resource that can be
* canceled before it ends. Generally, the only time a read-write transaction should be started is upon successful
* completion of the flow, triggered by reaching a 'commit' end state.
*
* @author Keith Donald
* @author Juergen Hoeller
@@ -74,6 +75,8 @@ import org.springframework.webflow.execution.ViewSelection;
*/
public class JpaFlowExecutionListener extends FlowExecutionListenerAdapter {
private static final String PERSISTENCE_CONTEXT_ATTRIBUTE = "persistenceContext";
private static final String ENTITY_MANAGER_ATTRIBUTE = "entityManager";
private EntityManagerFactory entityManagerFactory;
@@ -81,7 +84,7 @@ public class JpaFlowExecutionListener extends FlowExecutionListenerAdapter {
private TransactionTemplate transactionTemplate;
/**
* Create a new Session-per-Conversation listener using given JPA Entity Manager factory.
* Create a new JPA flow execution listener using given JPA Entity Manager factory.
* @param entityManagerFactory the entity manager factory to use
*/
public JpaFlowExecutionListener(EntityManagerFactory entityManagerFactory,
@@ -91,7 +94,7 @@ public class JpaFlowExecutionListener extends FlowExecutionListenerAdapter {
}
public void sessionCreated(RequestContext context, FlowSession session) {
if (session.getDefinition().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(session.getDefinition())) {
EntityManager em = entityManagerFactory.createEntityManager();
session.getScope().put(ENTITY_MANAGER_ATTRIBUTE, em);
bind(em);
@@ -99,19 +102,19 @@ public class JpaFlowExecutionListener extends FlowExecutionListenerAdapter {
}
public void resumed(RequestContext context) {
if (context.getActiveFlow().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(context.getActiveFlow())) {
bind(getEntityManager(context));
}
}
public void paused(RequestContext context, ViewSelection selectedView) {
if (context.getActiveFlow().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(context.getActiveFlow())) {
unbind(getEntityManager(context));
}
}
public void sessionEnded(RequestContext context, FlowSession session, AttributeMap output) {
if (session.getDefinition().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(session.getDefinition())) {
final EntityManager em = (EntityManager) session.getScope().remove(ENTITY_MANAGER_ATTRIBUTE);
Boolean commitStatus = session.getState().getAttributes().getBoolean("commit");
if (Boolean.TRUE.equals(commitStatus)) {
@@ -133,13 +136,17 @@ public class JpaFlowExecutionListener extends FlowExecutionListenerAdapter {
}
public void exceptionThrown(RequestContext context, FlowExecutionException exception) {
if (context.getActiveFlow().getAttributes().contains("persistenceContext")) {
if (isPersistenceContext(context.getActiveFlow())) {
unbind(getEntityManager(context));
}
}
// internal helpers
private boolean isPersistenceContext(FlowDefinition flow) {
return flow.getAttributes().contains(PERSISTENCE_CONTEXT_ATTRIBUTE);
}
private EntityManager getEntityManager(RequestContext context) {
return (EntityManager) context.getFlowScope().get(ENTITY_MANAGER_ATTRIBUTE);
}

8
spring-webflow/src/test/java/org/springframework/webflow/support/persistence/HibernateFlowExecutionListenerTests.java
View File

@@ -71,10 +71,11 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
// Session created and bound to conversation
final Session hibSession = (Session) context.getConversationScope().get("session");
final Session hibSession = (Session) flowSession.getScope().get("session");
assertNotNull("Should have been populated", hibSession);
listener.paused(context, ViewSelection.NULL_VIEW);
assertSessionNotBound();
@@ -106,6 +107,7 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean = new TestBean("Keith Donald");
@@ -128,6 +130,7 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean1 = new TestBean("Keith Donald");
@@ -161,6 +164,7 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean = new TestBean("Keith Donald");
@@ -182,6 +186,7 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
EndState endState = new EndState(flowSession.getDefinitionInternal(), "cancel");
@@ -201,6 +206,7 @@ public class HibernateFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
listener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean1 = new TestBean("Keith Donald");

36
spring-webflow/src/test/java/org/springframework/webflow/support/persistence/JpaFlowExecutionListenerTests.java
View File

@@ -16,6 +16,7 @@ import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.webflow.engine.EndState;
import org.springframework.webflow.execution.ViewSelection;
import org.springframework.webflow.test.MockFlowSession;
import org.springframework.webflow.test.MockRequestContext;
@@ -56,6 +57,7 @@ public class JpaFlowExecutionListenerTests extends TestCase {
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
jpaListener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean = new TestBean(1, "Keith Donald");
@@ -72,6 +74,40 @@ public class JpaFlowExecutionListenerTests extends TestCase {
assertFalse(flowSession.getScope().contains("hibernate.session"));
}
public void testFlowCommitsAfterMultipleRequests() {
assertEquals("Table should only have one row", 1, jdbcTemplate.queryForInt("select count(*) from T_BEAN"));
MockRequestContext context = new MockRequestContext();
MockFlowSession flowSession = new MockFlowSession();
flowSession.getDefinitionInternal().getAttributeMap().put("persistenceContext", "true");
jpaListener.sessionCreated(context, flowSession);
context.setActiveSession(flowSession);
assertSessionBound();
TestBean bean1 = new TestBean(1, "Keith Donald");
jpaTemplate.persist(bean1);
assertEquals("Table should still only have one row", 1, jdbcTemplate.queryForInt("select count(*) from T_BEAN"));
jpaListener.paused(context, ViewSelection.NULL_VIEW);
assertSessionNotBound();
jpaListener.resumed(context);
TestBean bean2 = new TestBean(2, "Keith Donald");
jpaTemplate.persist(bean2);
assertEquals("Table should still only have one row", 1, jdbcTemplate.queryForInt("select count(*) from T_BEAN"));
assertSessionBound();
EndState endState = new EndState(flowSession.getDefinitionInternal(), "success");
endState.getAttributeMap().put("commit", Boolean.TRUE);
flowSession.setState(endState);
jpaListener.sessionEnded(context, flowSession, null);
assertEquals("Table should only have three rows", 3, jdbcTemplate.queryForInt("select count(*) from T_BEAN"));
assertFalse(flowSession.getScope().contains("hibernate.session"));
assertSessionNotBound();
assertFalse(flowSession.getScope().contains("hibernate.session"));
}
private DataSource getDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName("org.hsqldb.jdbcDriver");