Make an executable JAR from a maven project - java

I have a question about using Apache Maven: I built a very simple Maven-based project. This works fine so far.
Now I want to make an executable JAR file from my target file. The problem here seems to be that the dependencies (external libraries) are not packaged together with my app.
I've already googled and found the maven-assembly-plugin. That actually does exactly what I want, but seems to be somewhat inflexible, since the dependencies are not automatically resolved and I can not specify file filters, etc. (or only with much effort over assembly.xml).
What I really like is the solution of spring-boot-maven-plugin, so automatically determine all linked JAR files and put in a lib folder. Now my little project is not a Spring application, so Spring Boot might not be suitable for me, right?
So what would interest me: Is there a way to get a similarly structured and executable JAR archive as spring-boot-maven-plugin builds?

Just use Maven Shade Plugin. It packages your dependencies inside your jar and you can specify the Java packages to exclude

Related

Maven: How to add all jar files in lib folder during a web application build

I have an old project. I am trying to add maven build to the project.
All the jar files in the project are present currently in the WEB-INF/lib folder.
Is there a way to add these jar files to the classpath during source compilation and then have it in the war file lib
This is one of the places where switching to Maven hurts. There are a lot of suggestions where most short-circuit something you will need later, and hurt you there. I would suggest that you
Move your jar files out of the lib folder into another project folder not meaning anything special to Maven.
For all jars that you easily recognize, make the proper Maven dependency in your pom file. This will allow Maven to download sources and javadoc if present.
For the remaining jars, you can tell Maven to install them as part of your normal build as custom dependencies. I asked the same question years back and got a very useful response at Multiple install:install-file in a single pom.xml. This will allow you to get up and running quickly.
When you have the time, locate proper replacements for your custom dependencies.
Take your time doing this. It is tedious work but it pays off quickly.

Deploy gradle to directory

This may have been asked to death, but I can't find an answer. I have a pretty simple java project (not web), its built with ant with sources located in ./src and dependencies in ./lib. Looking to modernize it to either maven or gradle. Since I've had good results with gradle and android, decided to go with gradle. That means I'll be dropping ./lib for dependency management.
However, I cannot figure out how to use grade to deploy the project. I would like to deploy manually for now. So I would need to have jar build from the sources and having all dependencies copied into lib (or whatever) directory where jar is.
So far... I'm getting nowhere quickly.
Gradle Application plugin is perfectly suited for this use-case.
the task distZip will create a deployable zip file complete with dependencies.

Adding plain Java project as a classpath to an eclipse plugin

I have a plain Java project (not a plugin project) which I want to add to a classpath of a eclipse plugin which I am developing. But in web projects I can add that project as a build path and it works fine. But I tried same thing in eclipse plugin, I am able to compile successfully, but at run time I am getting java.lang.ClassNotFoundException.
I know OSGi quite well and I know how to add OSGi into an classpath (using export-packages) but what I want is to add Standard, non-osgi project into an classpath, so that I wont' get runtime errors. Is there anyway I can achieve this?
I can export project as a jar file or make it as a plugin project and it would work fine. But that's not my option currently because, still that API is in pre-alpha stage, and there would be lot of changes going on. So I am trying to avoid pain of exporting it as jar file everytime. Is there any option for me other than this?
I have a similar situation: I want non-OSGi Maven dependencies integrated into the classpath of my plugin. I succeeded with a roundabout solution, which I think is the best I could get.
I have a build step outside of Eclipse where I copy the class files of the dependency into the plugin's lib folder. The lib folder is specified in MANIFEST.MF as an entry in Bundle-ClassPath and (here comes the hack) as a source folder in build.properties. That was the only way to make the plugin work both when launched from within Eclipse and when exported.

Add resource files to classpath using daemon(jsvc)

I am struggeling with this for a while.
I am using Spring3.1 in a standalone env. I have resources files which I need to add into the classpath (applicationXML). In eclipse it's a known and easy way. Now I am trying to deploy my application to a standalone env on linux using Daemon (commons-daemon-1.0.3.jar).
How can I add resources files there to the classpath?
One thing you can do is use the Maven Shade plugin. This is used to create a SuperJAR of everything in your build profile — dependent JARs from Apache and Spring, as well as your own code. The Shade Plugin can that add a Classpath entry of "." into the Manifest of the SuperJAR, this is precisely how you will be able to run the Main class of the SuperJAR, but have the classloader look in both a local directory as well as a JAR for all your components.
You'll have to adjust your build a bit so that things like log4j.properties and application-context.xml, and other files you wish to have sysadmins/customers modifer after build are kept out of the resources/path — otherwise they will get baked into the build.
You might look at my source code here http://sourceforge.net/projects/jee2pctest/. The client driver code provides an excellent example of how to use the Maven Shade plugin to create a directly executable JAR with external properties files.The magic is mainly in the pom.xml file. One Caveat, I am using the Maven build tooling, if you are still on ANT using using your IDE's built-in packager, then you might have some work cut out.

package all external classes in my jar, with Eclipse

I am working on a Hadoop project in Eclipse that depends on another one of my projects; I've included the other project in my build path, but when I export the dependent project, it only contains the classes from that same project.
Ordinarily, this would not be a problem, as I could just link the other project with the -cp flag, but Hadoop requires you to pass the jar as an argument, meaning that all of my dependencies must be inside that jar.
Is there a way, in Eclipse, to automatically build and include classes from projects that you depend on?
Thanks.
You coud use Ant to automatically build, test and export. It needs some time learning it, but its worth.
There are possible tasks (fileset, zipgroupfileset, copy) to include files, jars (unzipped) or anything into the final jar. By this way you definitly know whats inside your distribution jar and you don't need an eclipe installation running.
I suggest you take a look at maven as a build tool. You define the dependencies and build steps for each of your projects in files called pom files. The maven plugins for Eclipse (the m2e plugins) can take the configuration in the pom file and setup your Eclipse build paths and project description so that you can access the classes in your other project in Eclipse. Maven can also create a jar for you that has the classes from both projects (a "jar-with-dependencies").
In maven terms, your two projects are called "artifacts" with one having a dependency on the other.
The one downside to maven (and the cause for many negative comments about maven) is an initially steep learning curve that can be frustrating. What you're trying to do, however, is very straightforward and I expect you can find a number of examples showing you exactly what you want to do.
The first step, and that's what my answer is about, is to take a look at maven. It may seem overly complex, but it can scale to handle just about any build configuration you need as your hadoop apps get more and more complex.
You can export a project as a Runnable jar, which can be useful if you want a single jar, with dependencies included.
Select the Project. File > Export. Select the Java section. Select Runnable JAR file.
See related answer:
Eclipse: How to build an executable jar with external jar?

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