How to load a WAR module into Spring's built-in Tomcat running in a standalone? - spring

I am having three modules in my Maven project:
parent
rest-api # Spring REST API
web-client # AngularJS web client
application # Project to bundle it all up for a standalone
I am not sure if I have here an "elegant" solution so please hit me with a stick if that is complete garbage, but this is how it works - or how it's supposed to work:
rest-api
Module rest-api does simply offer the REST API and other core functionality - basically it is pure server code. It is a jar artifact.
web-client
To separate client and server code I am having the module web-client. It is a war project that hold the client webapp.
application
This module is supposed to glue it all up. It depends on rest-api and web-client. It does two important things:
It's pom.xml uses the spring-boot-maven-plugin to build a standalone runnable jar - my ultimate goal
It provides the main(String args[]) method that starts the #SpringBootApplication with SpringApplication.run(EasyModelAccessServer.class, args);
What I am currently able to is tell Eclipse to run this in a servlet container. The server boots up and I my two resources, the rest-api and the web-client working. Everything is fine so far.
The issue
What is not fully working is the standalone. If I package up the whole thing and run the server:
$ path/to/application: mvn clean package
$ path/to/application: java -jar target/application.jar
Only the REST API will work. The reason is because the web-client is not added or introduced as a web app to the Spring built-in Tomcat.
The question
is how I can make this work. There are two options which come to my mind:
Somehow sneak in the web-client.war file into the application.jar such that it is available as a resource and programmatically call tomcat.addWebapp("/web-client", "path/to/web-client.war") (or something like that) to load the additional service
Hope that the spring-boot-maven-plugin or another Spring Maven plug-in can do that for me and find somebody that links me to an example.
I've tried it with 1. but I didn't succeed to move web-client.war into application.jar but I am also not sure if I should actually do that.
FAQ
Q: "Why do you separate everything instead of merge all those modules into a server module where the Spring Maven plug-in would do everything for you out of the box?"
A: I really want to separate the client code from the server code. I could however merge web-client into application but last time I tried that I had 10 other issues why this did not work out so I decided to keep it that way and that it actually shouldn't be so hard to load an additional server resource.
Q: "Can I take a look at the project?"
A: Yes, you can. Just take a look: https://github.com/silentsnooc/easy-model-access Please forgive me that I am currently using tabs instead of whitespaces - I am going to change that as soon as I got everything up and running.

Related

url after spring maven deployment

I have a basic question about deployment but I can't seem to find an answer on google...
I am working on a jakarta project and it's the first time I do the deployment.
Since I am using Spring-boot maven, I know there is an embedded tomcat that will launch with the jar.
My issue is, I don't know what url to use to check my project is working...
Before, I used the address http://localhost:9091/contextPath/endpoint, but now, I only get a whiteScreen...
So my question is, what url should I use ? Also, is there something else to do after packaging ?
Thank you for your answers.
EDIT:
Alright, so I tried actuator but that didn't help me...
With /actuator/mappings, I could see that my endpoints are correctly configured but when I use the executable jar, http://localhost:9091/contextPath/endpoint odes not work while it does if I compile with my IDE...
I don't know what url to connect to just to see the index... I'm using a very basic spring framework (boot and mvc) and my IDE is intellij community if this helps anyone
EDIT 2:
I tried to deploy the app on a local Tomcat9 to see if something would change but the connexion is reinitialized everytime I try to deploy a war using the manager, and there was no trace of error in the logs.
I tried using ./mvnw and it did work, endpoint and all, but it implies working with IDE environment
I tried using java (openjdk 13) and it compiled, but i couldn"t acces my own endpoint. I could still access the actuator endpoints so i don't know what to make of it.
Should the url be different depending on whether we are using IDE environment or just the jar?
EDIT 3:
Ok, I think have a lead but I have no idea how to resolve this:
when I began the web part of the application, I created a WEB-INF folder where I put all my jsp. My js and css files were in the resources/static folder. I tried once to put the jsp in the resources folder but it didn't work so I didn't push too hard.
Now, when I unzip the jar, i find my css and js files, but not my jsp.
When I unzip my war file, I have everything, but when I try to deploy it on a separate tomcat server, the connexion resets and I don't know why because nothing is written in the logs.
The issue then becomes:
Right now, I have
└──src
└──main
├──java
├──resources
| ├──static
| | ├──css
| | └──js
| └──template
└──webapp
└──WEB-INF
└──classes
└──jsp
What is the standard tree in intellij with jsp ?
By default Spring Boot apps are on port 8080.
Can you try http://localhost:8080?
Port can be changed in application.properties (or application.yml, application-profile.properties etc.) via server.port property (e.g. server.port=8888).
Ok, I managed to make it work.
I'm going to describe here everything of note that I encountered.
First, when I called my app to the usual url, there was no response (whiteLabel).
I added test logs and i found that I indeed called m controller.
I unzipped the jar and war i produced and came to the conclusion that the issue was architectural. I couldn't use jar, I had to use the war file.
I tried to deploy on a local tomcat server using the manager, but it always resetted the connection, so I took the manual approach - copy pasting the war file in the webapp directory.
Finally, the web pages were accessible in the browser.
Thank you for all the tips given during my research!
`http://endpoint:{PORT}/actuator/health` or `http://endpoint:{PORT}/actuator/status`
it should help but it must require spring-boot-actuator as a dependency in your pom/gradle file.

Dart with Maven (in Spring Boot App)

I like Dart, I have been playing with it for a while. I'd like to integrate with my Maven web app project based on Spring Boot.
I suppose the correct way is to use dart-maven-plugin. But I'm not sure how to properly glue it in place. Spring Boot has its own structure, Maven as well and Dart makes that none the better.
I will need probably the entry point for Dart part, means Spring Boot templates folder needs to include the html resources from Dart.
I would appreciate any idea, best practices.
PS: the aforementioned dart-maven-plugin is not really vivid, should I be afraid using it at all, as I don't see any progress there, compared to Dart itself.
UPDATE
So this can be solution(note I have only one so called "entry point"- .dart file so far)
normal Dart structure in src/main/dart
user dart-maven-plugin's pub build command into ${project.build.directory}/dart
maven-resources-plugin:copy-resources from ${project.build.directory}/dart/web to ${project.build.directory}/classes/public/
make war
I'm still able to use Intellij's Dart integration from src/main/dart.
The Spring Boot maps classes/public/ folder to / so the dart file and html files are loaded properly.
It's not ideal, but it works so far. Please fell free to write down any comments.
I have tried a few times to use dart in a maven project myself and always ran into some problems. Right now I'm developing my dart apps in a separate module that I build with pub which connects to the maven based java backends with rest.
This has several advantages for me, for example:
I can use pub and avoid problems with outdated maven plugins
I use the serving mechanism that fits best for the static dart code and assets (in my case a docker image with nginx)
I have a clean separation of backend and frontend code with a tailored REST API
As I like the microservice approach I also use spring session together with zuul (via spring-cloud).
If you want to combine dart with generated html from for example JSPs or another templating engine, then this isn't a good approach for you. But IMHO dart is not yet very well suited for these kind of architectures.

Using Google App Engine modules for multi-thread backend update of a Cloud endpoints project

I'm building "read-only" webservice (Google Cloud Endpoints as backend for an Android App) so I created a project using maven:
mvn archetype:generate -Dappengine-version=1.9.10 -Dfilter=com.google.appengine.archetypes:
and selecting archetype hello-endpoints-archetype to have some sample code to work on.
This works well and my app is correctly calling the service as expected (and the service is correctly supplying the data in return).
Now I have to implement an "update" service to periodically (4 to 6 times a dya) update the data supplied to the app. So I added a servlet to my project to be called by cron. Trouble is: one of the library used during this update uses multi-threads which cause an AccessControlException to be thrown because apparently multi-thread is only allowed in backend modules...
But after having read dozens of pages on google app engine, I still don't know how to "break" my application into modules so that particular servlet would be run as a backend module while the already existing servlet keep working as they do. So far, all I got was that I should use an EAR application composed of several WAR modules, but I don't even know if my current application is an EAR or not...
I'm using Eclipse Luna, maven 3.2.1 (embeded with Eclipse), google app engine 1.9.10, writing in Java
Could anyone please help me by explaining the directory structure and/or configuration files I have to look at, modify and/or add?
Thanks for any help provided!
You can find an example of multi-modules project here.
However, note that even in backend modules the threading is limited to 50 threads, as stated here.

How to run a project containg drools in Tomcat7?

I have created a Dynamic web project which also uses drools for providing some functionality. When i put the WAR file in Tomcat7 and the server, the drools part does not work.
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
After this line which is first line relating to drools, nothing happens.
Is some configuration required to run my project containing drools 5.5.0 Final in the Tomcat7.
Please help me. I am badly stuck and I am new to drools.
You'll have to add some facts to the working memory and execute(fire) the rules. Check out these examples on GitHub
P.S. Probably not related to Tomcat in any way. Might be worth while to try getting the rules executed from command line app first.
You need to check all the dependencies that are added to your web application (WEB-INF/lib) make sure that drools has all the required deps there, because if not it will not be able to create the knowledge builder. Most of the time if it is failing is because that you forgot to add the deps in the web app.
The following project in GitHub is a web application, containing some REST-style endpoints for validating IBANs. It uses Drools 5.5 to perform that evaluation.
https://github.com/gratiartis/sctrcd-payment-validation-web/
It generates a .war which can be loaded into Tomcat, and could be a useful starting point. The knowledge base is wrapped within a Spring service:
https://github.com/gratiartis/sctrcd-payment-validation-web/blob/master/src/main/java/com/sctrcd/payments/validation/RuleBasedIbanValidator.java
Following through how that creates a knowledge base and session might help you see where your code is going wrong.
As a bonus, you can run it up in Tomcat using "mvn tomcat7:run" to test it out immediately.

Using spring in a stand alone jar for dependency injectection

Am a total beginner with spring framework and trying to know if it even fits my use case, before investing time learning it.
I'm responsible for a stand alone java project(used as a jar by a server) which basically serves requests from a server, and in turn makes service calls to various internal services.
This standalone java project, currently has all of its service calls hard coded. I want to use Spring to inject dependencies so I can make this stuff testable.
I have no idea how spring works. Does it even hold for standalone jars or is it only for 'running applications'?
If I make my standalone project 'spring enabled', when the server uses my jar, will it automagically work by creating beans or is there some requirement from the server side?
In short, yes, you can use Spring in a standalone jar-application ("console application", if you will), we do it all the time at work. You just need to create the ApplicationContext yourself when your application starts, see for example here: http://www.devdaily.com/blog/post/java/load-spring-application-context-file-java-swing-application
This is just one example I pulled straight out of Google, there are probably numerous others. Still, you really need to read at least the basics from the Spring documentation to get started, otherwise you'll probably hit a wall pretty soon.

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