Jonathan Lalou's Blog

Archive for the ‘en-US’ Category

Abstract

You would like to work on the client side of your GWT application, without building and deploying the Jetty server. Or, in the same way, you need test some server features available in WebLogic but not in Jetty, such as the EJB.
GWT 2.0 documentation, at the segment How do I use my own server in hosted mode instead of GWT’s built-in Jetty instance? is not precise at all on the 3rd step: it simply states:

“change the URL at the end of the argument list to match the URL you recorded in step #1.”

Process

• Let’s assume your WAR is deployed on http://distantMachine:8080/myApplication. The servlet container may be Tomcat or WebLogic, it does not matter
• In Eclipse, go in “Run Configuration...“. Duplicate your current and classic GWT application configuration.
• Go in Server , uncheck “Run built-in server“.
• In Arguments tab, write the following line:
  [java]-noserver -remoteUI "${gwt_remote_ui_server_port}:${unique_id}" -logLevel INFO -war C:\eclipse\workspace\myApplication\src\main\webapp\lalou.jonathan.web.gwt.MyApplication -startupUrl http://distantMachine:8080/myApplication lalou.jonathan.web.gwt.MyApplication[/java]
• Run
• The application is available at the following address:
  [html]http://distantMachine:8080/muyApplication/?gwt.codesvr=127.0.0.1:9997[/html]

Case

You run a GWT application, with a a service layer. Those services are tested through unit tests, which may use EasyMock, among other frameworks. Of course, you hinted at related jars, such us JUnit, by a <scope>test</scope> in your pom.xml.

Yet, when you run the GWT application with a Jetty light container, you get the following message:

Compiling module lalou.jonathan.gwt.client.MyModule

Validating newly compiled units

[java][ERROR] Errors in ‘file:/C:/eclipse/workspace/…/test/unit/lalou/jonathan/gwt/client//MyServiceUnitTest.java’
[ERROR] Line 26: No source code is available for type org.easymock.MockControl; did you forget to inherit a required module?
[ERROR] Line 76: No source code is available for type org.junit.Assert; did you forget to inherit a required module?[/java]

Fix

Since Maven2 and GWT scopes are fully independant, you have to modify you *.gwt.xml. Replace:

[xml] <source path=’client’/>[/xml]

with:

[xml]<source path=’client’ excludes="**/*UnitTest.java,**/*RuntimeTest.java"/>[/xml]

NB: Never forget that Google teams work with Ant, and not with Maven!

Case

This morning, I tried to redeploy an EAR on a WebLogic 9.2, using Maven 2 and a classical deployment profile. I got this issue:
[java][ERROR] BUILD ERROR
[INFO] ————————————————————————
[INFO] Error executing ant tasks

Embedded error: The following error occurred while executing this line:
(…)
weblogic.deploy.api.internal.utils.DeployerHelperException: The source ‘C:\DOCUME~1\myLogin\LOCALS~1\Temp\myApplication-ear.ear’ for the application ‘my-application-ear’ could not be loaded to the server ‘http://myServer:1234/bea_wls_deployment_internal/DeploymentService’.
Response: ‘403: Forbidden’ for url: ‘http://myServer:1234/bea_wls_deployment_internal/DeploymentService'[/java]

Yesterday, I got a similar error when I launched a mvn tomcat:deploy to deploy a WAR on a Tomcat 6.0 server:
[java][ERROR] BUILD ERROR
[INFO] ————————————————————————
[INFO] Cannot invoke Tomcat manager

Embedded error: Server returned HTTP response code: 403 for URL: http://myServer:3210/manager/deploy?path=%2FmyWebArchive&war=&update=true[/java]

Quick Fix

Running Maven2 in offline line, ie adding the option "-o", allows me to redeploy both the EAR on WebLogic and the WAR on Tomcat.
eg: mvn tomcat:deploy -o
I keep on investigating on this matter. I think there is an issue on the DNS. Indeed, when I deploy locally to my own machine myServer (ie with its network name), this error is raised, but when I deploy to localhost the build is successful.

Context

In a GWT application, you have to use RPC calls, using entities which are package in external jar archives. With Eclipse, no error appears ; yet when you build the project with Maven2, you get this message:

[java][INFO] [ERROR] Errors in ‘file:/C:/eclipse/workspace/myGwtProject/src/java/com/lalou/jonathan/web/gwt/client/component/JonathanPanel.java’
(…)
[INFO] [ERROR] Line 24: No source code is available for type com.lalou.jonathan.domain.MyEntity; did you forget to inherit a required module?
(…)
[INFO] Finding entry point classes[/java]

Fix

In related jar

In the project to which MyEntity belongs to (here: my/depended/project):

• create a file com/lalou/jonathan/MyDependedProject.gwt.xml, with as content:

  [xml]<module>
  <source path="">
  <include name="**/MyEntity.java"/>
  </source>
  </module>[/xml]

• In the pom.xml:
  • Add the source MyEntity.java in built jar. This way, the Java file itself will be considered as a resource, like an XML or property file. To perform this, the quickest manner is to add the following block in the pom.xml:
    [xml]<resources>
    <resource>
    <directory>${basedir}/src/java</directory>
    <includes>
    <include>**/MyEntity.java</include>
    </includes>
    </resource>
    </resources>[/xml]
  • Add an <include>**/*.gwt.xml</include> so that to have to MyDependedProject.gwt.xml file in the built jar.

  In GWT project

  In your *.gwt.xml file, add the dependency:

  [xml]<inherits name=’com.lalou.jonathan.MyDependedProject’ />[/xml]

  Caution!

  All these operations need be done on all dependencies -either direct or indirect-. Therefore, possibly you may have a huge amount of code to be got.
  Another issue appears when you use a jar of which you do not have the source code, such as in the case of tiers API for instance.

Abstract

Let’s assume you have followed the article “Basic RPC call with GWT“. Now you would like to call an actual EJB 2 as remote, via a Spring lookup.
Let’s say: you have an EJB MyEntrepriseComponentEJB, which implements an interface MyEntrepriseComponent. This EJB, generates a remote MyEntrepriseComponentRemote.

Entry Point

In myApplication.gwt.xml entry point file, after the line:

[xml]<inherits name=’com.google.gwt.user.User’/>[/xml]

add the block:

[xml]
<inherits name=’com.google.gwt.user.User’ />
<inherits name="com.google.gwt.i18n.I18N" />
<inherits name="com.google.gwt.http.HTTP" />[/xml]

Add the line:

[xml]<servlet path=’/fooService.do’/>[/xml]

Client

Under the *.gwt.client folder:

Update the service interface. Only the annotation parameter is amended:

[java]@RemoteServiceRelativePath("services/fooService")
public interface FooService extends RemoteService {
public String getHelloFoo(String fooName);
}[/java]

You have nothing to modify in asynchronous call interface (FooServiceAsync).

Server

Under the *.gwt.server folder, update the implementation for service interface:

Change the super-class, replacing RemoteServiceServlet with GWTSpringController:

[java]public class FooServiceImpl extends GWTSpringController implements FooService {
public FooServiceImpl() {
// init
}
}
[/java]

Add new field and its getter/setter:

[java]// retrieved via Spring
private myEntrepriseComponent myEntrepriseComponent;

public myEntrepriseComponent getMyEntrepriseComponent() {
return myEntrepriseComponent;
}

public void setmyEntrepriseComponent(myEntrepriseComponent _myEntrepriseComponent) {
myEntrepriseComponent = _myEntrepriseComponent;
}[/java]

Write the actual call to EJB service:

[java]
public String getHelloFoo(String fooName) {
return myEntrepriseComponent.getMyDataFromDB();
}
}[/java]

web.xml

Fill the web.xml file:

[xml]<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>

<!– Spring –>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<servlet>
<servlet-name>gwt-controller</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
<servlet-name>gwt-controller</servlet-name>
<url-pattern>/myApplication/services/*</url-pattern>
</servlet-mapping>

<!– Default page to serve –>
<welcome-file-list>
<welcome-file>MyApplicationGwt.html</welcome-file>
</welcome-file-list>

</web-app>
[/xml]

JNDI

Add a jndi.properties file in src/resources folder:

[java]
java.naming.provider.url=t3://localhost:12345
java.naming.factory.initial=weblogic.jndi.WLInitialContextFactory
java.naming.security.principal=yourLogin
java.naming.security.credentials=yourPassword
weblogic.jndi.enableDefaultUser=true[/java]

These properties will be used by Spring to lookup the remote EJB. The last option is very important, otherwise you may happen to face issues with EJB if they were deployed under WebLogic.

WEB-INF

In the WEB-INF folder, add an applicationContext.xml file:

[xml]<?xml version="1.0" encoding="UTF-8"?>
<beans>

<util:properties id="jndiProperties" location="classpath:jndi.properties" />

<jee:remote-slsb id="myEntrepriseComponentService"
jndi-name="ejb.jonathan.my-entreprise-component"
business-interface="lalou.jonathan.myApplication.services.myEntrepriseComponent"
environment-ref="jndiProperties" cache-home="false"
lookup-home-on-startup="false" refresh-home-on-connect-failure="true" />

</beans>[/xml]

Add a gwt-controller-servlet.xml file:

[xml]<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">

<bean>
<property name="order" value="0" />
<property name="mappings">
<value>
/fooService=fooServiceImpl
</value>
</property>
</bean>

<bean id="fooServiceImpl"
class="lalou.jonathan.myApplication.web.gwt.server.FooServiceImpl">
<property name="myEntrepriseComponent" ref="myEntrepriseComponentService" />
</bean>
</beans>
[/xml]

Of course, if your servlet mapping name in web.xml is comoEstasAmigo, then rename gwt-controller-servlet.xml as comoEstasAmigo-servlet.xml 😉

Build and deploy

Now you can compile, package your war and deploy under Tomcat or WebLogic. WebLogic server may raise an error:
java.rmi.AccessException: [EJB:010160]Security Violation: User: '<anonymous>' has insufficient permission to access EJB
This error is related to the rights required to call a method on the EJB. Indeed, two levels of rights are used by WebLogic: firstly to lookup / instanciate the EJB (cf. the property java.naming.security.principal we set sooner), and another to call the method itself. In this second case, WebLogic requires an authentication (think of what you do when you login an web application deployed: your login and rights are kept for all the session) to grant the rights. I wish to handle this subject in a future post.

NB: thanks to David Chau and Didier Girard from SFEIR, Sachin from Mumbai team and PYC from NYC.

Case

I had to automatize the deployment of a basic GWT application, packaged as a WAR archive, on a WebLogic 9.2 server.

Maven 2

Mojo Plugin

Firstly, I tried to use Mojo’s maven plugin for Weblogic. I had to add some lines in my pom.xml, almost identical to those available in Mojo’s documentation.

The main issue I encountered was to retrieve the jars mandatory to the plugin, and install them in my local Maven repository. Since the missing jars names given by Maven are not so obvious, here are the paths to retrieve these jars, all included with WebLogic 9.2 installation:

[java]mvn install:install-file -DgroupId=weblogic -DartifactId=xbean -Dversion=9.2 -Dpackaging=jar -Dfile=%BEA_HOME%\server\lib\wlxbean.jar
mvn install:install-file -DgroupId=weblogic -DartifactId=wlw-langx -Dversion=9.2 -Dpackaging=jar -Dfile=%BEA_HOME%\server\lib\wlw-langx.jar
mvn install:install-file -DgroupId=weblogic -DartifactId=wlw-util -Dversion=9.2 -Dpackaging=jar -Dfile="%BEA_HOME%\common\lib\wlw-util.jar"
mvn install:install-file -DgroupId=weblogic -DartifactId=bcel -Dversion=5.1 -Dpackaging=jar -Dfile="%BEA_HOME%\javelin\lib\bcel-5.1.jar"
mvn install:install-file -DgroupId=weblogic -DartifactId=javelinx -Dversion=9.2 -Dpackaging=jar -Dfile="%BEA_HOME%\javelin\lib\javelinx.jar"
mvn install:install-file -DgroupId=weblogic -DartifactId=weblogic-container-binding -Dversion=9.2 -Dpackaging=jar -Dfile="%BEA_HOME%\server\lib\schema\weblogic-container-binding.jar"[/java]

Issues

Once this issue fixed, I tried to launch the deployment (with mvn weblogic:deploy). But I encountered the following error:
Response: '404: Not Found' for url: 'http://localhost:7070/bea_wls_deployment_internal/DeploymentService'
Complete stacktrace in debug and verbose mode:

[java]weblogic.deploy.api.internal.utils.DeployerHelperException: The source ‘C:\LOCALS~1\Temp\appliGWT-1.0-SNAPSHOT.war’ for the application ‘iVarGwt’ could not be loaded to the server ‘http://localhost:7070/bea_wls_deployment_internal/DeploymentService’.
Response: ‘404: Not Found’ for url: ‘http://localhost:7070/bea_wls_deployment_internal/DeploymentService’
at weblogic.deploy.api.internal.utils.JMXDeployerHelper.uploadSource(JMXDeployerHelper.java:658)
at weblogic.deploy.api.spi.deploy.internal.ServerConnectionImpl.upload(ServerConnectionImpl.java:653)
at weblogic.deploy.api.spi.deploy.internal.BasicOperation.uploadFiles(BasicOperation.java:319)
at weblogic.deploy.api.spi.deploy.internal.BasicOperation.execute(BasicOperation.java:411)
at weblogic.deploy.api.spi.deploy.internal.BasicOperation.run(BasicOperation.java:169)
at weblogic.deploy.api.spi.deploy.WebLogicDeploymentManagerImpl.deploy(WebLogicDeploymentManagerImpl.java:369)
at weblogic.deploy.api.tools.deployer.DeployOperation.execute(DeployOperation.java:47)
at weblogic.deploy.api.tools.deployer.Deployer.perform(Deployer.java:139)
at weblogic.deploy.api.tools.deployer.Deployer.runBody(Deployer.java:88)
at weblogic.utils.compiler.Tool.run(Tool.java:158)
at weblogic.utils.compiler.Tool.run(Tool.java:115)
at weblogic.Deployer.run(Deployer.java:70)
at org.codehaus.mojo.weblogic.DeployMojoBase.executeDeployer(DeployMojoBase.java:510)
at org.codehaus.mojo.weblogic.DeployMojo.execute(DeployMojo.java:49)
at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:451)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:558)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:512)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:482)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:330)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:291)
at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:142)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:336)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:129)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:287)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)[/java]

Deploying another application worked, deploying my application using WebLogic console worked too… After many hours of search, I gave up Maven2 way.

Ant

After retiring from using Mojo’s plugin, I used a way I feared would be less elegant: Ant.

Indeed, Ant script is very short and efficient:

[xml]<?xml version="1.0" encoding="UTF-8"?>

<project name="redeploy" basedir="." default="deploy">
<property file="redeploy.properties" />

<target name="init-weblogic-task">
<available file="${env.WL_HOME}/server/lib/weblogic.jar"
property="weblogic-jar.present" />
<fail unless="weblogic-jar.present">${env.WL_HOME}/server/lib/weblogic.jar does not
exist</fail>

<taskdef name="wldeploy" classname="weblogic.ant.taskdefs.management.WLDeploy"
classpath="${env.WL_HOME}/server/lib/weblogic.jar" />
</target>

<target name="deploy" depends="init-weblogic-task">
<wldeploy action="deploy" source="${source}"
name="${name}" user="${user}" password="${password}" verbose="true"
adminurl="${adminurl}" debug="true" targets="${targets}" upload="true"
securitymodel="${securitymodel}" stage="stage" />
</target>

</project>[/xml]

In the same folder, I created a property file, gathering the properties hinted at in Ant build.xml.

[java]env.WL_HOME=C:/bea/weblogic_9_2
adminurl=t3://localhost:7070
name=appliGWT
user=weblogic
password=myPassword
targets=myTarget
securitymodel=Advanced
source=../../../target/appliGWT-1.0-SNAPSHOT.war
[/java]

I launched Ant and the deployment was successful.

Maven anyway, but with Ant

Yet, since I build with Maven, I do not want to have to build, change folder, and then deploy: I want a unique command line to package and deploy. To perform that, I added a profile in my pom.xml, using a Maven plugin to call Ant tasks:

[xml] <profiles>
<profile>
<id>deploy</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.4.2</version>
<configuration>
<skipTests>true</skipTests>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<ant antfile="./src/resources/ant/build.xml"
target="deploy"
inheritall="false" inheritrefs="false"/>
</tasks>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>[/xml]

At last, my target was OK: I can build and deploy with a simple mvn package -Pdeploy

Let’s assume you have a “Hello World” GWT application. You need emulate a basic RPC call (RMI, EJB, etc.). Here is the program:

Under the *.gwt.client folder:

Create an service interface:

[java]@RemoteServiceRelativePath("fooService")
public interface FooService extends RemoteService {
public String getHelloFoo(String totoName);
}[/java]

Create another interface for asynchronous call. You can notice the method name differs lightly from the one in the other interface:

[java]public interface FooServiceAsync {
void getHelloFoo(String fooName, AsyncCallback<String> callback);
}[/java]

Under the *.gwt.server folder, create an implementation for service interface:

[java]public class FooServiceImpl extends RemoteServiceServlet implements FooService {
public FooServiceImpl() {
// TODO init
}

public String getHelloFoo(String fooName) {
// TODO call actual service
return "hello world!";
}
}[/java]

In the web.xml file, add the following blocks:

[xml] <!– Servlets –>
<servlet>
<servlet-name>fooService</servlet-name>
<servlet-class>com…….server.FooServiceImpl</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>fooService</servlet-name>
<url-pattern>/ivargwt/fooService</url-pattern>
</servlet-mapping>
[/xml]

The tags content match the argument given as parameter to RemoteServiceRelativePath annotation above.

From then, in your concrete code, you can instantiate the service and call remote method:

[java]FooServiceAsync fooService = GWT.create(FooService.class);
fooService.getHelloFoo("how are you?", new AsyncCallback<String>() {

public void onSuccess(String result) {
MessageBox.alert("OK", result, null);
}

public void onFailure(Throwable caught) {
MessageBox.alert("ERROR", "rpc call error-" + caught.getLocalizedMessage(), null);
}
});
[/java]

Now you can compile, package your war and deploy under Tomcat or WebLogic.

NB: special to “black-belt GWT guy” David Chau from SFEIR.

These days, I am discovering GWT, and more accurately ExtGWT, aka GXT.

Case

I have to write a “Hello World” application based on GXT.

Steps

• Firstly, follow Lars Vogel’s tutorial to have a “Hello World” in GWT.
• In Eclipse, add a dependancy from your project to extjs-gxt-lib-2.1.1.jar (version compatible with your GWT version: 1.7 or 2.0), available at this link.
• In your *.gwt.xml file, remove:
  [xml]<inherits name=’com.google.gwt.user.theme.standard.Standard’/>[/xml]

  and add:

  [xml]<inherits name=’com.extjs.gxt.ui.GXT’/>[/xml]

• Get the gxt-all.css file, copy it into war/css/ folder
• In your *.html file, add the lines:
  [xml]<link rel="stylesheet" type="text/css" href="css/gxt-all.css" />[/xml]
• Now, adapt your Java entry point source class, replacing GWT widgets with GXT ones.
• Restart your server and refresh the page in your browser. You have your “Hello World” in GXT!

Error

Could not connect to remote service [ejb.services.myEjb]; nested exception is java.rmi.ConnectException: This RJVM has already been shutdown 4967659282374941940S:myServer:[7404,7404,-1,-1,-1,-1,-1]:myDomain:myEjbInstance

Explanation

Your EJB instance tries to lookup for a remote instance which seems to be shutdown. There may be many causes: IP / hostname resolution failed, remote servers are actually unreachables (such in the case of network issues), etc. Another potential issue may come from a bug in cluster management by WebLogic. Such a bug was identified and fixed by BEA with version 8 release ; yet, the bug may have kept on occuring on later version (9.2 in my case).
In my current case, the issue was that webservices, theorically deployed in the same WebLogic, were not started. Once the web services started, the issue vanished.

Case

Your have a multi-module project. For any reason, the build fails on your 32nd project (out of 70).
You indentify the issue, fix it, and need rebuild your project. Yet, you don’t want to rebuild the 31 first projects. Rather, you prefer to start on the 32nd one.
On older version of Maven, you had to edit your pom.xml, comment the 31 projects, launch the build and uncomment the projects.

Fix

From Maven 2.1, a new option is available: -rf or —resume-from. Thanks to this option, you can hint to Maven to restart the build at any point you like.