- 26.1. Basic Seam configuration
- 26.2. Using Alternate JPA Providers
- 26.3. Configuring Seam in Java EE 5
- 26.4. Configuring Seam in J2EE
- 26.5. Configuring Seam in Java SE, without JBoss Embedded
- 26.6. Configuring Seam in Java SE, with JBoss Embedded
- 26.7. Configuring jBPM in Seam
- 26.8. Configuring SFSB and Session Timeouts in JBoss AS
- 26.9. Running Seam in a Portlet
Configuration is a very boring topic and an extremely tedious pastime. Unfortunately, several lines of XML are required to integrate Seam into your JSF implementation and servlet container. There's no need to be too put off by the following sections; you'll never need to type any of this stuff yourself, since you can just copy and paste from the example applications!
First, let's look at the basic configuration that is needed whenever we use Seam with JSF.
Of course, you need a faces servlet!
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.seam</url-pattern>
</servlet-mapping>
(You can adjust the URL pattern to suit your taste.)
In addition, Seam requires the following entry in your web.xml file:
<listener>
<listener-class>org.jboss.seam.servlet.SeamListener</listener-class>
</listener>
This listener is responsible for bootstrapping Seam, and for destroying session and application contexts.
Some JSF implementations have a broken implementation of server-side state saving that interferes
with Seam's conversation propagation. If you have problems with conversation propagation during form
submissions, try switching to client-side state saving. You'll need this in web.xml:
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
If you want follow our advice and use facelets instead of JSP, add the following lines to
faces-config.xml:
<application>
<view-handler>com.sun.facelets.FaceletViewHandler</view-handler>
</application>
And the following lines to web.xml:
<context-param>
<param-name>javax.faces.DEFAULT_SUFFIX</param-name>
<param-value>.xhtml</param-value>
</context-param>
The Seam Resource Servlet provides resources used by Seam Remoting, captchas (see the security
chapter) and some JSF UI controls. Configuring the Seam Resource Servlet requires the following entry in
web.xml:
<servlet>
<servlet-name>Seam Resource Servlet</servlet-name>
<servlet-class>org.jboss.seam.servlet.SeamResourceServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Seam Resource Servlet</servlet-name>
<url-pattern>/seam/resource/*</url-pattern>
</servlet-mapping>
Seam doesn't need any servlet filters for basic operation. However, there are several features which
depend upon the use of filters. To make things easier, Seam lets you add and configure
servlet filters just like you would configure other built-in Seam components. To take advantage of this
feature, we must first install a master filter in web.xml:
<filter>
<filter-name>Seam Filter</filter-name>
<filter-class>org.jboss.seam.servlet.SeamFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>Seam Filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
The Seam master filter must be the first filter specified in
web.xml. This ensures it is run first.
The Seam filters share a number of common attributes, you can set these in
components.xml in addition to any parameters discussed
below:
url-pattern— Used to specify which requests are filtered, the default is all requests.url-patternis a Tomcat style pattern which allows a wildcard suffix.regex-url-pattern— Used to specify which requests are filtered, the default is all requests.regex-url-patternis a true regular expression match for request path. It's worth noting when composing the regular expression that the request path does not contain the server or request context path.disabled— Used to disable a built in filter.
Adding the master filter enables the following built-in filters.
This filter provides the exception mapping functionality in pages.xml (almost
all applications will need this). It also takes care of rolling back uncommitted transactions when
uncaught exceptions occur. (According to the Java EE specification, the web container should do this
automatically, but we've found that this behavior cannot be relied upon in all application servers.
And it is certainly not required of plain servlet engines like Tomcat.)
By default, the exception handling filter will process all requests, however this behavior may be
adjusted by adding a <web:exception-filter> entry to
components.xml, as shown in this example:
<components xmlns="http://jboss.com/products/seam/components"
xmlns:web="http://jboss.com/products/seam/web">
<web:exception-filter url-pattern="*.seam"/>
</components>
This filter allows Seam to propagate the conversation context across browser redirects. It intercepts any browser redirects and adds a request parameter that specifies the Seam conversation identifier.
The redirect filter will process all requests by default, but this behavior can also be adjusted
in components.xml:
<web:redirect-filter url-pattern="*.seam"/>
This feature is necessary when using the Seam file upload JSF control. It detects multipart form
requests and processes them according to the multipart/form-data specification (RFC-2388). To
override the default settings, add the following entry to components.xml:
<web:multipart-filter create-temp-files="true"
max-request-size="1000000"
url-pattern="*.seam"/>
create-temp-files— If set totrue, uploaded files are written to a temporary file (instead of held in memory). This may be an important consideration if large file uploads are expected. The default setting isfalse.max-request-size— If the size of a file upload request (determined by reading theContent-Lengthheader in the request) exceeds this value, the request will be aborted. The default setting is 0 (no size limit).
Sets the character encoding of submitted form data.
This filter is not installed by default and requires an entry in
components.xml to enable it:
<web:character-encoding-filter encoding="UTF-16"
override-client="true"
url-pattern="*.seam"/>
encoding— The encoding to use.override-client— If this is set totrue, the request encoding will be set to whatever is specified byencodingno matter whether the request already specifies an encoding or not. If set tofalse, the request encoding will only be set if the request doesn't already specify an encoding. The default setting isfalse.
If RichFaces is used in your project, Seam will install the
RichFaces Ajax filter for you, making sure to install it
before all other built-in filters. You don't need to install
the RichFaces Ajax filter in web.xml
yourself.
The RichFaces Ajax filter is only installed if the RichFaces jars are present in your project.
To override the default settings, add the following entry to components.xml.
The options are the same as those specified in the RichFaces Developer Guide:
<web:ajax4jsf-filter force-parser="true"
enable-cache="true"
log4j-init-file="custom-log4j.xml"
url-pattern="*.seam"/>
force-parser— forces all JSF pages to be validated by Richfaces's XML syntax checker. Iffalse, only AJAX responses are validated and converted to well-formed XML. Settingforce-parsertofalseimproves performance, but can provide visual artifacts on AJAX updates.enable-cache— enables caching of framework-generated resources (e.g. javascript, CSS, images, etc). When developing custom javascript or CSS, setting to true prevents the browser from caching the resource.log4j-init-file— is used to setup per-application logging. A path, relative to web application context, to the log4j.xml configuration file should be provided.
This filter adds the authenticated user name to the log4j mapped diagnostic context so that it can be included in formatted log output if desired, by adding %X{username} to the pattern.
By default, the logging filter will process all requests, however this behavior may be
adjusted by adding a <web:logging-filter> entry to
components.xml, as shown in this example:
<components xmlns="http://jboss.com/products/seam/components"
xmlns:web="http://jboss.com/products/seam/web">
<web:logging-filter url-pattern="*.seam"/>
</components>
Requests sent direct to some servlet other than the JSF servlet are not processed through the JSF lifecycle, so Seam provides a servlet filter that can be applied to any other servlet that needs access to Seam components.
This filter allows custom servlets to interact with the Seam contexts. It sets up the Seam
contexts at the beginning of each request, and tears them down at the end of the request. You should
make sure that this filter is never applied to the JSF
FacesServlet. Seam uses the phase listener for context management in a JSF
request.
This filter is not installed by default and requires an entry in
components.xml to enable it:
<web:context-filter url-pattern="/media/*"/>
The context filter expects to find the conversation id of any conversation context in a request
parameter named conversationId. You are responsible for ensuring that it gets
sent in the request.
You are also responsible for ensuring propagation of any new conversation id back to the client.
Seam exposes the conversation id as a property of the built in component
conversation.
Seam can install your filters for you, allowing you to specify where in the
chain your filter is placed (the servlet specification doesn't provide a well defined order if you
specify your filters in a web.xml). Just add the @Filter
annotation to your Seam component (which must implement javax.servlet.Filter):
@Startup
@Scope(APPLICATION)
@Name("org.jboss.seam.web.multipartFilter")
@BypassInterceptors
@Filter(within="org.jboss.seam.web.ajax4jsfFilter")
public class MultipartFilter extends AbstractFilter {
Adding the @Startup annotation means thar the component is available during
Seam startup; bijection isn't available here (@BypassInterceptors); and the filter
should be further down the chain than the RichFaces filter
(@Filter(within="org.jboss.seam.web.ajax4jsfFilter")).
We need to apply the SeamInterceptor to our Seam components. The simplest way to
do this across an entire application is to add the following interceptor configuration in
ejb-jar.xml:
<interceptors>
<interceptor>
<interceptor-class>org.jboss.seam.ejb.SeamInterceptor</interceptor-class>
</interceptor>
</interceptors>
<assembly-descriptor>
<interceptor-binding>
<ejb-name>*</ejb-name>
<interceptor-class>org.jboss.seam.ejb.SeamInterceptor</interceptor-class>
</interceptor-binding>
</assembly-descriptor>
Seam needs to know where to go to find session beans in JNDI. One way to do this is specify the
@JndiName annotation on every session bean Seam component. However, this is quite
tedious. A better approach is to specify a pattern that Seam can use to calculate the JNDI name from the
EJB name. Unfortunately, there is no standard mapping to global JNDI defined in the EJB3 specification,
so this mapping is vendor-specific. We usually specify this option in components.xml.
For JBoss AS, the following pattern is correct:
<core:init jndi-name="myEarName/#{ejbName}/local" />
Where myEarName is the name of the EAR in which the bean is deployed.
Outside the context of an EAR (when using the JBoss Embeddable EJB3 container), the following pattern is the one to use:
<core:init jndi-name="#{ejbName}/local" />
You'll have to experiment to find the right setting for other application servers. Note that some servers (such as GlassFish) require you to specify JNDI names for all EJB components explicitly (and tediously). In this case, you can pick your own pattern ;-)
In an EJB3 environment, we recommend the use of a special built-in component for transaction management,
that is fully aware of container transactions, and can correctly process transaction success events
registered with the Events component. If you don't add this line to your
components.xml file, Seam won't know when container-managed transactions end:
<transaction:ejb-transaction/>
There is one final item you need to know about. You must place a seam.properties,
META-INF/seam.properties or META-INF/components.xml file in
any archive in which your Seam components are deployed (even an empty properties file will do). At
startup, Seam will scan any archives with seam.properties files for seam components.
In a web archive (WAR) file, you must place a seam.properties file in the
WEB-INF/classes directory if you have any Seam components included here.
That's why all the Seam examples have an empty seam.properties file. You can't
just delete this file and expect everything to still work!
You might think this is silly and what kind of idiot framework designers would make an empty file
affect the behavior of their software?? Well, this is a workaround for a limitation of the
JVM—if we didn't use this mechanism, our next best option would be to force you to list every
component explicitly in components.xml, just like some other competing frameworks do!
I think you'll like our way better.
Seam comes packaged and configured with Hibernate as the default JPA provider.
If you require using a different JPA provider you must tell seam
about it.
This is a workaround
Configuration of the JPA provider will be easier in the future and will not require configuration changes, unless you are adding a custom persistence provider implementation.
Telling seam about a different JPA provider can be be done in one of two ways:
Update your application's components.xml
so that the generic PersistenceProvider takes
precedence over the hibernate version. Simply add the following
to the file:
<component name="org.jboss.seam.persistence.persistenceProvider"
class="org.jboss.seam.persistence.PersistenceProvider"
scope="stateless">
</component>
If you want to take advantage of your JPA provider's
non-standard features you will need to write you own implementation of
the PersistenceProvider. Use
HibernatePersistenceProvider as a starting
point (don't forget to give back to the community :). Then you
will need to tell seam to use it as before.
<component name="org.jboss.seam.persistence.persistenceProvider"
class="org.your.package.YourPersistenceProvider">
</component>
All that is left is updating the persistence.xml
file with the correct provider class, and what ever properties your
provider needs. Don't forget to package your new provider's jar files in the
application if they are needed.
If you're running in a Java EE 5 environment, this is all the configuration required to start using Seam!
Once you've packaged all this stuff together into an EAR, the archive structure will look something like this:
my-application.ear/
jboss-seam.jar
lib/
jboss-el.jar
META-INF/
MANIFEST.MF
application.xml
my-application.war/
META-INF/
MANIFEST.MF
WEB-INF/
web.xml
components.xml
faces-config.xml
lib/
jsf-facelets.jar
jboss-seam-ui.jar
login.jsp
register.jsp
...
my-application.jar/
META-INF/
MANIFEST.MF
persistence.xml
seam.properties
org/
jboss/
myapplication/
User.class
Login.class
LoginBean.class
Register.class
RegisterBean.class
...
You should declare jboss-seam.jar as an ejb module in META-INF/application.xml;
jboss-el.jar should be placed in the EAR's lib directory (putting it in the EAR classpath.
If you want to use jBPM or Drools, you must include the needed jars in the EAR's lib directory.
If you want to use facelets (our recommendation), you must include
jsf-facelets.jar in the WEB-INF/lib directory of the WAR.
If you want to use the Seam tag library (most Seam applications do), you must include
jboss-seam-ui.jar in the WEB-INF/lib directory of the WAR. If
you want to use the PDF or email tag libraries, you need to put jboss-seam-pdf.jar or
jboss-seam-mail.jar in WEB-INF/lib.
If you want to use the Seam debug page (only works for applications using facelets), you must include
jboss-seam-debug.jar in the WEB-INF/lib directory of the WAR.
Seam ships with several example applications that are deployable in any Java EE container that supports EJB 3.0.
I really wish that was all there was to say on the topic of configuration but unfortunately we're only about a third of the way there. If you're too overwhelmed by all this tedious configuration stuff, feel free to skip over the rest of this section and come back to it later.
Seam is useful even if you're not yet ready to take the plunge into EJB 3.0. In this case you would use Hibernate3 or JPA instead of EJB 3.0 persistence, and plain JavaBeans instead of session beans. You'll miss out on some of the nice features of session beans but it will be very easy to migrate to EJB 3.0 when you're ready and, in the meantime, you'll be able to take advantage of Seam's unique declarative state management architecture.
Seam JavaBean components do not provide declarative transaction demarcation like session beans do. You
could manage your transactions manually using the JTA
UserTransaction or declaratively using Seam's @Transactional
annotation. But most applications will just use Seam managed transactions when using Hibernate with
JavaBeans.
The Seam distribution includes a version of the booking example application that uses Hibernate3 and JavaBeans instead of EJB3, and another version that uses JPA and JavaBeans. These example applications are ready to deploy into any J2EE application server.
Seam will bootstrap a Hibernate SessionFactory from your
hibernate.cfg.xml file if you install a built-in component:
<persistence:hibernate-session-factory name="hibernateSessionFactory"/>
You will also need to configure a managed session if you want a Seam managed
Hibernate Session to be available via injection.
<persistence:managed-hibernate-session name="hibernateSession"
session-factory="#{hibernateSessionFactory}"/>
Seam will bootstrap a JPA EntityManagerFactory from your
persistence.xml file if you install this built-in component:
<persistence:entity-manager-factory name="entityManagerFactory"/>
You will also need to configure a managed persistence context if you want a
Seam managed JPA EntityManager to be available via injection.
<persistence:managed-persistence-context name="entityManager"
entity-manager-factory="#{entityManagerFactory}"/>
We can package our application as a WAR, in the following structure:
my-application.war/
META-INF/
MANIFEST.MF
WEB-INF/
web.xml
components.xml
faces-config.xml
lib/
jboss-seam.jar
jboss-seam-ui.jar
jboss-el.jar
jsf-facelets.jar
hibernate3.jar
hibernate-annotations.jar
hibernate-validator.jar
...
my-application.jar/
META-INF/
MANIFEST.MF
seam.properties
hibernate.cfg.xml
org/
jboss/
myapplication/
User.class
Login.class
Register.class
...
login.jsp
register.jsp
...If we want to deploy Hibernate in a non-EE environment like Tomcat or TestNG, we need to do a little bit more work.
It is possible to use Seam completely outside of an EE environment. In this case, you need to tell Seam
how to manage transactions, since there will be no JTA available. If you're using JPA, you can tell
Seam to use JPA resource-local transactions, ie. EntityTransaction, like so:
<transaction:entity-transaction entity-manager="#{entityManager}"/>
If you're using Hibernate, you can tell Seam to use the Hibernate transaction API like this:
<transaction:hibernate-transaction session="#{session}"/>
Of course, you'll also need to define a datasource.
A better alternative is to use JBoss Embedded to get access to the EE APIs.
JBoss Embedded lets you run EJB3 components outside the context of the Java EE 5 application server. This is especially, but not only, useful for testing.
The Seam booking example application includes a TestNG integration test suite that runs on JBoss Embedded
via SeamTest.
The booking example application may even be deployed to Tomcat.
Embedded JBoss must by installed into Tomcat for Seam applications to run correctly on it. Embedded JBoss only runs on JDK 1.5 (not JDK 1.6). Embedded JBoss can be downloaded here. The process for installing Embedded JBoss into Tomcat 6 is quite simple. First, you should copy the Embedded JBoss JARs and configuration files into Tomcat.
Copy all files and directories under the Embedded JBoss
bootstrapandlibdirectories, except for thejndi.propertiesfile, into the Tomcatlibdirectory.Remove the
annotations-api.jarfile from the Tomcatlibdirectory.
Next, two configuration files need to be updated to add Embedded JBoss-specific functionality.
Add the Embedded JBoss listener to
conf/server.xml. It should appear after all other listeners in the file.<Listener className="org.jboss.embedded.tomcat.EmbeddedJBossBootstrapListener"/>
WAR file scanning should be enabled by adding a listener to
conf/context.xml.<Listener className="org.jboss.embedded.tomcat.WebinfScanner"/>
For more configuration options, please see the Embedded JBoss Tomcat integration wiki entry.
The archive structure of a WAR-based deployment on an servlet engine like Tomcat will look something like this:
my-application.war/
META-INF/
MANIFEST.MF
WEB-INF/
web.xml
components.xml
faces-config.xml
lib/
jboss-seam.jar
jboss-seam-ui.jar
jboss-el.jar
jsf-facelets.jar
jsf-api.jar
jsf-impl.jar
...
my-application.jar/
META-INF/
MANIFEST.MF
persistence.xml
seam.properties
org/
jboss/
myapplication/
User.class
Login.class
LoginBean.class
Register.class
RegisterBean.class
...
login.jsp
register.jsp
... Most of the Seam example applications may be deployed to Tomcat by running ant
deploy.tomcat.
Seam's jBPM integration is not installed by default, so you'll need to enable jBPM by installing a
built-in component. You'll also need to explicitly list your process and pageflow definitions. In
components.xml:
<bpm:jbpm>
<bpm:pageflow-definitions>
<value>createDocument.jpdl.xml</value>
<value>editDocument.jpdl.xml</value>
<value>approveDocument.jpdl.xml</value>
</bpm:pageflow-definitions>
<bpm:process-definitions>
<value>documentLifecycle.jpdl.xml</value>
</bpm:process-definitions>
</bpm:jbpm>
No further special configuration is needed if you only have pageflows. If you do have business process
definitions, you need to provide a jBPM configuration, and a Hibernate configuration for jBPM. The Seam DVD
Store demo includes example jbpm.cfg.xml and hibernate.cfg.xml files
that will work with Seam:
<jbpm-configuration>
<jbpm-context>
<service name="persistence">
<factory>
<bean class="org.jbpm.persistence.db.DbPersistenceServiceFactory">
<field name="isTransactionEnabled"><false/></field>
</bean>
</factory>
</service>
<service name="tx" factory="org.jbpm.tx.TxServiceFactory" />
<service name="message" factory="org.jbpm.msg.db.DbMessageServiceFactory" />
<service name="scheduler" factory="org.jbpm.scheduler.db.DbSchedulerServiceFactory" />
<service name="logging" factory="org.jbpm.logging.db.DbLoggingServiceFactory" />
<service name="authentication"
factory="org.jbpm.security.authentication.DefaultAuthenticationServiceFactory" />
</jbpm-context>
</jbpm-configuration>
The most important thing to notice here is that jBPM transaction control is disabled. Seam or EJB3 should control the JTA transactions.
There is not yet any well-defined packaging format for jBPM configuration and process/pageflow definition files. In the Seam examples we've decided to simply package all these files into the root of the EAR. In future, we will probably design some other standard packaging format. So the EAR looks something like this:
my-application.ear/
jboss-seam.jar
lib/
jboss-el.jar
jbpm-3.1.jar
META-INF/
MANIFEST.MF
application.xml
my-application.war/
META-INF/
MANIFEST.MF
WEB-INF/
web.xml
components.xml
faces-config.xml
lib/
jsf-facelets.jar
jboss-seam-ui.jar
login.jsp
register.jsp
...
my-application.jar/
META-INF/
MANIFEST.MF
persistence.xml
seam.properties
org/
jboss/
myapplication/
User.class
Login.class
LoginBean.class
Register.class
RegisterBean.class
...
jbpm.cfg.xml
hibernate.cfg.xml
createDocument.jpdl.xml
editDocument.jpdl.xml
approveDocument.jpdl.xml
documentLifecycle.jpdl.xml It is very important that the timeout for Stateful Session Beans is set higher than the timeout for HTTP
Sessions, otherwise SFSB's may time out before the user's HTTP session has ended. JBoss Application Server
has a default session bean timeout of 30 minutes, which is configured in
server/default/conf/standardjboss.xml (replace default with your
own configuration).
The default SFSB timeout can be adjusted by modifying the value of max-bean-life in
the LRUStatefulContextCachePolicy cache configuration:
<container-cache-conf>
<cache-policy>org.jboss.ejb.plugins.LRUStatefulContextCachePolicy</cache-policy>
<cache-policy-conf>
<min-capacity>50</min-capacity>
<max-capacity>1000000</max-capacity>
<remover-period>1800</remover-period>
<!-- SFSB timeout in seconds; 1800 seconds == 30 minutes -->
<max-bean-life>1800</max-bean-life>
<overager-period>300</overager-period>
<max-bean-age>600</max-bean-age>
<resizer-period>400</resizer-period>
<max-cache-miss-period>60</max-cache-miss-period>
<min-cache-miss-period>1</min-cache-miss-period>
<cache-load-factor>0.75</cache-load-factor>
</cache-policy-conf>
</container-cache-conf>
The default HTTP session timeout can be modified in
server/default/deploy/jbossweb-tomcat55.sar/conf/web.xml for JBoss 4.0.x, or in
server/default/deploy/jboss-web.deployer/conf/web.xml for JBoss 4.2.x. The following
entry in this file controls the default session timeout for all web applications:
<session-config>
<!-- HTTP Session timeout, in minutes -->
<session-timeout>30</session-timeout>
</session-config>
To override this value for your own application, simply include this entry in your application's own
web.xml.
If you want to run your Seam application in a portlet, take a look at the JBoss Portlet Bridge, an implementation of JSR-301 that supports JSF within a portlet, with extensions for Seam and RichFaces. See http://labs.jboss.com/portletbridge for more.