I have a Java Project, for which I'm now creating a Web interface, using a Dynamic Web Project from Eclipse. The Web project consists of a single servlet and two JSP's. Something like this:
/JavaApplication
/src
/lib
/resources
/WebApplication
/src
/Servlet.java
/WebContent
/WEB-INF
index.jsp
other.jsp
Now, I need to reference JavaApplication from WebApplication, in order to use its classes to process web requests. What's the best way to accomplish this ? My idea is to create a .jar of the JavaApplication, containing all the .class files, /resources, and /libs. In this way, I could include the .jar in the web application, and I could have a single .war file that contained the entire application.
What do you think? How is this problem typically solved ?
Note: I don't want to convert the Java Project into a Web project.
In Eclipse project properties, add the project to the Java EE Module Dependencies (Eclipse 3.5 or older)
or Deployment Assembly (Eclipse 3.6 or newer) entry in the project properties.
This way Eclipse will take care about doing the right thing to create a WAR out of this all (it will end in /WEB-INF/lib). No other configuration is necessary, even not some fiddling in Build Path.
Under Eclipse, you can declare Project References for a given project, the web application in your case. To do so, right click on your web application project, then go for Properties > Project References and select the JavaApplication project. This should allow you to call code from the JavaApplication project from the WebApplication without having to build a WAR. This is a solution for development.
For standard deployment (outside the IDE), you should indeed create a standard WAR. To do so, you'll have to package your JavaApplication as a JAR including the .class files and the files under /resources but not the libraries it depends on (JARs under /lib). These dependencies will actually end up in the WEB-INF/lib directory of the WAR, beside the JAR of your JavaApplication. These steps are typically automated with tools like Ant or Maven.
Connecting java app to web app for development :
right click on web project :
properties>project references> add the java project you want to refer
Now in properties tab of web project go to
properties>deployment assembly> add the project manually and run the app
Consider moving up to EAR level, if your web container supports that.
The tricky part with shared code is where should the common code be put. A copy pr web application? A copy in the web container? Overdoing the "share these classes" might end up in class loader problems.
If you are creating two separate web applications refactor common java code into a separate Eclipse project and refer to it from both WAR projects.
EDIT: Apparently I have misread the problem description, and thought you asked about an existing and a new web application sharing code.
If you have an Eclipse project with your application, and another with your web frontend, then you can let your application export the necessary resources which the "Export WAR" in Eclipse Java EE can wrap up in a jar file and put in WEB-INF/lib for you. You need to say this explicitly with a checkmark in Properties -> Java EE Module Dependencies for your web project. Expect you have to experiment a bit - this took me a while to learn.
Typically you would create an API interface using remote service beans from the Java application that expose the methods that you want to invoke in the web application. You would include a proxy of the API interface with your web application that calls the remote service bean in the Java application. Remember that you will need to register the remote bean in the web.xml file.
Related
My project generates a Jar as the output package and uses an external War file, available on our Artifactory, as the Web Application to be deployed on Tomcat (currently using version 7). This War file contains all libs and modules required for the application to run.
I have already packaged and ran those projects outside eclipse on a "vanilla" Tomcat installation. In this scenario, the Jar my project generates is loaded on the context.xml file this way:
<Loader className="org.apache.catalina.loader.VirtualWebappLoader" virtualClasspath="/home/igor/workspace/myapp/myapp-2.4.3.jar"/>
Is there a way I can deploy this project on Tomcat using Eclipse and still be able to debug it? Can I use the Jar generated for this purpose or do I have to deploy the workspace project?
As for the War file, do (or can) I have to add it as an dependency?
Thanks in advance!
EDIT
We actually provide an Web Framework, which is packaged as a war. Other applications that use that framework are exported as jars and loaded into the framework through the context file as cited above.
Your question is confusing probably because of your custom plugin/classloader and deployment which is sort of orthogonal to debugging.
What I recommend is you keep whatever system you have to build/package/deploy and use JVM remote debugging. That is do not use the Eclipse WTP since you seem to have custom steps for deployment but rather build your code deploy & run a separate Tomcat instance and then run the remote debugger in Eclipse.
You will get some hotcode swapping with this method but not as much as something like JRebel.. (which you could use also) it will certainly be better than constantly redeploying.
I am trying to recreate an existing project with Maven (any IDE is ok, but mainly Netbeans), and I'm a bit confused about the best way to do this, so any help is greatly appreciated.
Currently I have an Enterprise application with the following components:
Web application (some jsps, servlets).
Ejb project
Client project (Swing application / applet)
Common project (Contains common files used by the applet and the Web app).
The problem is the packaging and dependencies, currently the Client (Applet) jar is packaged within the Web application, so that when the web app is deployed, the users can access the applet via their browser.
Is there any similar existing archetype for this, or does it require heavy customization ?
Oh, and I am using Glassfish 3.1
Thanks in advance.
So first of all, for me it looks like you need multi module maven project. In that case there will be no single archetype that will fulfill your needs.
When it comes to "the Client (Applet) jar is packaged within the Web application" you can use maven-dependency-plugin (http://maven.apache.org/plugins/maven-dependency-plugin/) and its goal:
dependency:copy - takes a list of artifacts defined in the plugin configuration section and copies them to a specified location, renaming them or stripping the version if desired. This goal can resolve the artifacts from remote repositories if they don't exist in local.
I have an existing project that I'm trying to convert correctly into an Eclipse Dynamic Web Project. I've mostly got it working, however there is on issue that I'm not sure how to fix.
The project has something like 2 modules that share the same Java classes, but need to be deployed as separate webapps into the app server (Tomcat 5.5).
So the folder structure is something like
/Webcontent_root
----/app1
..../WEB-INF etc...
----/app2
..../WEB-INF etc...
Is this something that can be controlled within eclipse?
Thanks
I guess, eclipse can't control project with more than one context.
Approach I.
I think you should create three projects: regular java project with classes, one dynamic web project for first webcontent and one for second. Than tune up "Java Build Path" and "Deployment Assembly" settings.
Approach II.
Or you can create two web projects, first with classes and webcontent, second with webcontent and link to first project ("Java Build Path" and "Deployment Assembly" settings).
Create 2 web project and 1 java project for the shared java source. Both web project can use the shared project as a jar file in their web-inf/lib
As #Nantipov says, use the deployment assembly screen to make web projects get the shared java project as a jar in the library filder.
Yes, it can--just not with the UI in WTP (deployment has always been a sore spot and ongoing effort to improve). The .settings/org.eclipse.wst.common.component in your project controls what Eclipse/WTP thinks of as web content root(s) in your project. Odds are you just need to create a new folder in the project and add it as a sibling to the existing element in that file, but with a correct source-path value.
Hi all i have very rare problem which needs to be solved.
Problem/issue:
I have a dynamic web project which is already built and i have war file of that project.
I need to apply some customizations on top of the war file given to me.
Using maven or ant am able to compile the custom code written by me and able to add produced class files to the war file.
But the this is happening for final war file build.
when i want to test my code in eclipse. the war file build and deployed in jboss plugin contains only the class files produced out of java files written by me..........
Please help me how can i modify the .classpath file of my project so that a jboss publish can build a war file using the dependent war file which can run on eclipse-jboss to test my custom code....
Advance Thanks.....
Not a rare problem.
What you need to combine two web applications (wars) together. You have your customization war on which you need to overlay the existing web application.
It looks like you have already solved it from build perspective and looking for Eclipse support. To my knowledge, Eclipse lacks support for this. You probably need to manually do the necessary configuration to make this happen.
It looks strange to me to have two WAR files.
Perhaps you have to consider to package your customizations in a JAR and inserting that jar in the original WAR file.
Otherwise, another solution, and what I do often with open-source project to customize is to have three projects in your workspace.
PRJ-src (with your original sources/JAR/WAR)
PRJ-custom (which depends of the previous one); This project contains only the new classes or custom spring xml files (with injection of my own classes)
PRJ (the merge of the two previous projects)
I create an Ant task in the 3rd project which takes the 1st project (PRJ-src) and merge with the 2nd project (PRJ-custom). This is possible to do so with Maven as well.
Then this is the only project I deploy in my app server (tomcat / jboss).
So I started with a web services project (just a dynamic web project) that builds and debugs correctly from eclipse. We've pulled a chunk of common code out that we want to put into a shared library so now those classes are going into a separate jar project that the web project references.
On the web project, I did Project->Properties->Java Build Path->Projects->Add and added the jar project. And this correctly solved all the compile-time classpath problems and everything builds fine. But at runtime, when the tomcat server fires up, spring attempts to inject some of the classes contained in the jar file and I get a NoClassDefFoundError.
My .class and properties files and the contents of my META-INF directory are showing up in the ./build directory, but my WEB-INF/lib directory seems to be referenced in-place, and the jar dependency doesn't get copied in to it to show up as part of the Web App Library.
What is the magical incantation to tell eclipse that the other jar project needs to be available to tomcat at runtime? From our ant build script, we first just build the other project into WEB-INF/lib and everything works fine, but not for eclipse debugging.
I figured this out after spending some time on it. If you are in Eclipse Helios , go to properties > deployment assembly > add > project and select the dependent project you wish to add.
Java EE module dependencies would solve this problem.
You have already done the task of extracting your common classes into its own project, possibly because other projects depend on these classes. Either way, you'll have to ensure that this is a Utility project (appears under Java EE in the project wizards), and not just a plain Java project.
One that is done, you can proceed to add the Utility project to your build path (compile-time path) as you have figured out.
The additional (final) step is to establish a Java EE module dependency between your Dynamic Web project and the shared library, which causes the utility's classes to be placed in WEB-INF\lib during deployment, and even during export of the WAR. To do so, visit the dynamic web project's properties, and browse to the Java EE module dependencies. Ensure that your utility project is selected here. Redeploy/publish your application and you should be good to go.