3 Maven Eclipse Tips for Java Developers

Hello guys, If you are using Maven inside Eclipse IDE via M2Eclipse plugin then the following tips can help you a lot. Maven is one of the essential tool for Java developers as it is used to build your application, compile your code, create packages which can be deployed into physical box or cloud. Apart from that Maven also provide dependency management feature which means you don't need to manually download JAR file and add into your classpath. You just specify which library your code is using and the version and Maven will automatically download correct JAR file for you and put in your local Maven repository. Maven can also manage transitive dependency which means suppose your code is depend on Spring Framework which itself need 10 more open source library to work. With Maven you just need to specify which version f spring framework you want to use, and it will download all the library needed by Spring automatically.  In nutshell, Maven makes Java development easier and every Java developer should learn it. 
Even though you can use Maven on command line most of us use Maven in our IDE like Eclipse or Intellij IDEA itself. That's where knowing these tips can make your productive. It will not only allow you to use Maven better but also help you to troubleshoot any Maven or build related issue in your IDE like Eclipse. 

3 Tips to use Maven Effectively on Eclipse IDE

Without any further ado, here is the the 3 tips to use Maven build tool effectively in Eclipse IDE.  If you have used Maven with Eclipse or ItelliJIDEA then you may know them already but if you don't you will love them like me when I first found them. 

1. Setup Dependency as Java Project in Eclipse

If your POM dependencies are another project in Eclipse then your project will automatically get updated whenever you build the dependent project. For example, let's say you have a project, ABC, which is dependent on two core modules e.g. framework.jar and persistence.jar, if you have checked out these project and has set up them as Maven Eclipse project, M2Eclipse can directly add them as a dependency, instead of loading their JAR files from the repository, be it local or remote.

You can verify this by expanding Maven dependency in your project, as shown below. You should see the project folder instead of JAR in place of dependency. By the way, to make this work, you must have the same version in pom.xml of ABC and framework.jar project. For example, if ABC needs 1.0.0.SNAPSHOT version of framework and framework pom.xml also has 1.0.0.SNAPSHOT.

The moment they go out of sync, Maven fallback to loading JAR from the repository option. What is the benefit of it? Well, you can build your dependency right there and also update your main project, you can also navigate and debug to the dependent source.

I have noticed one issue while using this feature, sometimes even after building a dependent project, the main project is not updated automatically in Eclipse, if this happens just select your main project, right-click, choose Maven, and select update project.

Btw, if you are just starting with Maven, I suggest you first go through a comprehensive Maven course like Apache Maven: Beginner to Guru to learn some fundamentals. It will not only help you to build and deploy your Java and Spring Boot projects using Maven but also learn Maven itself in depth.

2. Customizing Goals

You are not limited to Maven build commands provided by default to you e.g. When you right-click on any Maven Java project and select "Run as", you can see all these options as "Maven Build", Maven Clean, etc. You can create your own Maven build configuration, select the goals you want. 

For example, I usually use a Maven run configuration with goals like "clean compile package test" or sometimes just "clean compile package". You can also choose options like Update Snapshots, Debug Output, Skip Tests, etc.

3. Updating Maven Settings.xml

Whenever you change your proxy details on settings.xml file of the Maven config directory, don't forget to also load the updated file in Eclipse, otherwise, the M2Eclipse plugin will not be able to connect to the remote Maven central repository.

That's all about some quick Maven Eclipse tips for Java developers. Both Maven and Eclipse are great tools and every Java developer should be familiar with them. They also go along nicely because of the M2Eclipse plugin. Yes, there are some initial hiccups but once you cross that barrier it's smooth sailing.

I have saved a lot of time using Maven directly from Eclipse, no need to search JAR, download them from the internet and then finally add them into the build path of the Eclipse project, all can be done in a couple of clicks using Maven dependency management features. You can also read Maven for Eclipse of Packt to learn more tips about using Maven in Eclipse.



Other Maven Eclipse articles you may like to explore

• Difference between Maven, ANT and Jenkins? (answer)
• Top 10 Maven Plugins Every Java developer should know (see here)
• How to install Maven on Windows 10? (tutorial)
• Maven dependency search not working in Eclipse? (solution)
• My favorite free Maven courses for Java developers (free courses)
• How to increase heap size of Maven? (steps)
• How to remote debug Java application in Eclipse? (tutorial)
• 10 Eclipse debugging tips Java developer should know? (see here)
• Free Maven books for Java developers (see here)

Thanks for reading this article so far. If you like these Maven Tips then please share with your friends and colleagues. IF you have any questions or feedback then please drop a note.