calling java component with multiple java classes from Mule - mule

I am using Anypont Studio 5.3.0 and server runtime 3.7.0. I want to invoke a main() method from my component. Application is developed using Maven, SpringBoot and JPA. It sits in the jar file and have the following structure.
com
package
Application.class (with main method)
another package
Other classes
lib
other jars
META-INF
persistance.xml
MANIFEST.MF
Org
springframework boot loader and other spring classes.
when file arrives with file pattern that I detect with mule polling component I would like to invoke Java component in mule flow that has main class and all the supporting classes.
Thanks,
David

did you mavenize your Application? If yes, you can add that as a dependency in your mule project pom, which is also mavenize. But you need to make sure that the jars are added in your maven repository i.e. execute first "mvn clean install" to your java application. Otherwise, add the jars in you build path. When you are able to do those, you can create a spring bean or create a java component in mule where they could call your class with main() method.

I never came across this kind of production scenario where there is a need to call main method of java class in enterprise application. Are you sure you have only main method to access other classes, it should have initialize, spring way of injection etc. Simple answer to you question, create a mule java component and override onCall method to call Application(class).main. I will never do this kind of stuff [for sure it will give more problems based on what is being written in main method]. In general we will use main method invocation in desktop application. if possible work on (or let the application team to work on) jar file to have better initializing options

Related

Jenkins shared libraries with kotlin

I have to add some kotlin-written classes at groovy-written shared library to use it in my jenkins pipeline. However, these classes aren't available:
WorkflowScript: 19: unable to resolve class package.name.KotlinClass
And i don't have the same problem with groovy classes. I think the problem is i don't declare any tasks like compileKotlin, but where should i declare it? What drives the building of sources from shared plugin libraries and is this process configurable?
If I understand the problem correctly, you have a shared library in Jenkins, which a pipeline makes use of. Within that shared library, you would like your groovy to call onto classes compiled from kotlin.
The best approach to this would be to have a separate process compile the kotlin and publish a JAR into a maven repository. Once that is done, your groovy shared library can fetch the JAR using #Grab. This is covered in https://www.jenkins.io/doc/book/pipeline/shared-libraries/#using-third-party-libraries and broadly works like so:
#Grab('org.apache.commons:commons-math3:3.4.1')
import org.apache.commons.math3.primes.Primes
void parallelize(int count) {
if (!Primes.isPrime(count)) {
error "${count} was not prime"
}
// …
}
If you want to resolve that JAR from your own private maven repository as opposed to Maven Central, you can also add the #GrabResolver annotation as documented here https://docs.groovy-lang.org/latest/html/documentation/grape.html#Grape-SpecifyAdditionalRepositories
#GrabResolver(name='restlet', root='http://maven.restlet.org/')
#Grab('org.apache.commons:commons-math3:3.4.1')
A problem you will run into here is that you cannot add credentials into that #GrabResolver and I am not aware of a way to get credentials into the groovy sandbox to make that work for Jenkins shared libraries.
An alternative approach, as hinted by Jenkins own documentation is to build the required functionality into it's own executable, and make sure that executable is available in the build process the Jenkins shared library is being called in.

If kotlin package has multiple main function, how can I call specific one?

I want to test the main function for competitive programming.
Kotlin can have multiple main functions, however how to call specific one?
In other words, how to specify a function in the specific file?
It depends on compilation and execution tools:
When you call "java -jar my-app.jar", JVM looks into the manifest file to find main class name.
If you compile application with Gradle, you can define mainClassName as part of application plugin (which created executable jar).
Maven tool has property for the main class too.
IntelliJ Idea has independent settings, so you can specify multiple build configuration with different parameters. And you can put entry point there.

Mule ClassNotFoundException for class existing in a library in the class path

I have a class in a Mule application which resides in a jar of a third party library. The library gets included in the lib folder after the project builds so it is definitely in the classpath. The class is then used in a Mule component. The applications deploys successfully in AnyPoint Studio'sembedded server. However, when the Mule component is processing data, Mule complains that it can't find the class.
As soon as the line with the following code snippet is encountered it throws the NoClassDefFoundError.
populator.put(ScanType.MRI,container);
Here is a portion of the stacktrace:
Root Exception stack trace:
java.lang.ClassNotFoundException: com.tcfg.utils.defn.Populator
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at org.mule.module.launcher.FineGrainedControlClassLoader.findClass(FineGrainedControlClassLoader.java:175)
at org.mule.module.launcher.MuleApplicationClassLoader.findClass(MuleApplicationClassLoader.java:134)
at org.mule.module.launcher.FineGrainedControlClassLoader.loadClass(FineGrainedControlClassLoader.java:119)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
I also know that this is the only instance of the class in the whole project when I use a tool to search the entire lib folder for instances of the class. This is definitely not a situation of multiple versions of the class or of other classes existing in one of the jars with a similar name. What could be the cause of this and how can I resolve it?
Even though if you add the jar in lib folder you need to manually add that jar to your class path.So, that it will be available.
They are 2 possibilities here one is there might be a need of OS specific library to be downloaded and configured in Anypoint Stduio in Run configurations like for SAP we need to point it to the DLL which windows will refer to. Giving below an example.
-Djava.library.path=C:\Users\adm-snandu\AnypointStudio\workspace\
For most of the Class Notfound errors you need to make sure the maven dependency is given in the pom.xml which takes care of downloading all the relevant libraries and referring to them during run time.

Custom Gradle configurations by example

I am developing a library (JAR) that is meant to be used across many projects. I am using SLF4j for logging, and so I have declared the SLF4J API JAR to be a compile configuration.
When I'm developing this library locally on my machine, I'd like to run tests and see the output from all the SLF4J log statements. Or, outside of a test, it helps to add a temporary main(String[]) method to a random class and test functionality and log output as if the lib was an executable JAR. Since SLF4J's default binding is a No-Op (no output whatsoever), I have been getting by so far by adding the SLF4J Simple binding as a compile configuration dependency while I am developing & testing. Then, before I commit and publish, I simply remove the Simple binding as a dependency (since each developer who uses my lib should be able to select their own binding).
This is hacky and I know Gradle support custom configs, but I have yet to see a coherent example that could act as a guide. Ideally I'd like to define a custom dev configuration so that as a dependency I could have:
dependencies {
compile 'org.slf4j:slf4j-api:1.7.5'
dev 'org.slf4j:slf4j-simple:1.7.5' // Only used when running/testing locally
}
...but then ony the SLF4J API JAR gets added to my pom. Any ideas as to how to accomplish this? Perhaps Gradle already has such a concept built into it, or perhaps a custom configuration isn't even the right approach.

Invalid ejb jar: it contains zero ejb.

I have 2 modules: ejb and war, and ear module, that contains them. Modules build successfully, but when I try to deploy ear to glassfish, I recieve this error:
glassfish3.1.2|javax.enterprise.system.tools.admin.org.glassfish.deployment.admin|_ThreadID=17;_ThreadName=Thread-2;|Exception while deploying the app [EarModule] : Invalid ejb jar [BackEnd-1.0-SNAPSHOT.jar]: it contains zero ejb.
Note:
1. A valid ejb jar requires at least one session, entity (1.x/2.x style), or message-driven bean.
2. EJB3+ entity beans (#Entity) are POJOs and please package them as library jar.
3. If the jar file contains valid EJBs which are annotated with EJB component level annotations (#Stateless, #Stateful, #MessageDriven, #Singleton), please check server.log to see whether the annotations were processed properly.|#]
I really don't know what to do, I've found a lot of questions like mine, but there was no solution.
I understood, what was wrong. The problem was in run configurations, I'm using Intellij Idea and in run configurations there was build and make before run of my ear module. I removed this and after maven install it deployed successfully.
You have to add an EJB into your WAR or EAR file. Just Create a new Class and annotate it with #Stateless
I know this is very build specific and it uses Netbeans instead of the OP's IDE but because I was lead here and this will likely be useful to some users:
I had the following build:
Netbeans Enterprise Application with Maven
Glassfish 4.1
Java EE 7
I had tried migrating from a previous non-maven enterprise application and the clone didn't quite work the way I expected, there was some old ejb jars lying around that I deleted.
I had done quite a few things to fix it:
Ensure theres no ejb jars lying around that shouldn't be there. Ensure that you don't have accidently have the ejb module jar included more than once as this can result in the same error too (Manually deploying the ear and deployment through netbeans sometimes gave me different errors).
I used the #Remote interface on my EJB applications. Now you should not be importing your EJB into your War, you should use the annotations correctly as described https://docs.oracle.com/javaee/7/tutorial/ejb-intro004.htm
(This is more of a note) When you update any of your war or ejb, clean and build them before cleaning and building your ear (sounds funny right?).
If you are using interfaces for your session beans then you should put them in a separate jar, make a new project maven > java application. Do the same thing with your persistence entities. Add these as dependencies to both your ejb and war project.
This doesn't relate to me in particular but you should have at least 1 #stateless (or I think #stateful) annotation in a java class inside your ejb module for it to run (for the module to be considered an ejb).
I likely had to do a few more things that I forgot but if you still run into issues comment below and I'll try to update.
Just try to build & install your project using Maven , and then , deploy it in glassfish ( do not run your project directly from your IDE )
I encountered this problem as well. It occurred when I had imported a new EJB project into my Eclipse workspace. The project didn't have a reference to the Glassfish libraries then, since it was not yet included in the EAR deployment assembly.
Upon saving the Bean file, the IDE automatically imported javax.inject.Singleton instead of javax.ejb.Singleton. This made the code compile without warnings, but throw the same error as in the original post.