How to build JARs from IntelliJ IDEA properly?

Review project structure and settings

Before moving to artifact configuration, ensure your project is set up correctly. Check the project's structure and settings under File > Project Structure > Project Settings. Here, you can examine the dependencies which play a crucial role in correctly building your JAR.

Deciding on packaging strategy

An essential decision while building a JAR is whether to bundle dependencies within the JAR or keep them separate. Bundling is easy for execution but can inflate the size of the JAR. You can tweak these settings under artifact configuration.

Using Maven for building JARs

For Maven-based projects, you can use the maven-assembly-plugin for building the JAR with dependencies. Add assembly:single to your Maven run/debug configurations. Define the appropriate source and target versions in maven-compiler-plugin for Java compatibility.

<!-- THE plugin for JAR lovers 😏 -->
<plugin>
    <artifactId>maven-assembly-plugin</artifactId>
    <configuration>
        <archive>
            <manifest>
                <addClasspath>true</addClasspath>
                <mainClass>{your_package}.{your_main_class}</mainClass>
                <!-- Don't worry, she'll be your main –class– 😎 -->
            </manifest>
        </archive>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
    </configuration>
</plugin>
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Make sure to place the MANIFEST.MF in the resources directory.

Building and validating your JAR

Once everything is set, rebuild the artifacts. This will build the fresh JAR with all your latest changes. Remember, building a perfect JAR is not a one-hit wonder; it's all about iteration. Finally, run your JAR using the java -jar command to test it.

Assuming your Maven project is up to date (always remember to clean and install before building), you should be ready to rock!

Automating JAR updates

Automate JAR updates by adjusting the IntelliJ's artifact settings to 'Build on make.' This will auto-rebuild your JAR every time you make changes. Just remember to save your changes in IntelliJ before initiating the Build.

Potential JAR issues and how to overcome them

Once built, verify the JAR's contents in the output directory to ensure the JAR isn't empty. If you got a big fat nada, you've missed something. Return to the start and evaluate your configuration.

Visual Learners, Unite!

Those better with visuals, consider following video tutorials or screenshots. IntelliJ IDE configuration interfaces can be overwhelming, but with the right visual guidance, they can become your new best friend.

Beware of environment differences

Remember, your development environment might not mirror your production environment. Were those file paths relevant? Were the resources configured correctly? Always validate your project components before packing a suitcase and heading out into production.

Dealing with additional resources

Remember to include resources like images or property files in your JAR package. They are often overlooked but crucial for application functionality.

Advanced touchups

Having built your JAR, you might still need to make adjustments. This could be tweaking the manifest file or deciding how dependencies are packaged within the JAR - to perfect your JAR, iteration is key!