Understanding POM dependencies

Maven helps manage the third-party libraries in your operating system. In the olden days, you might have had to copy each third-party library into your project manually. This could be a big problem when you had more than one project. Maven avoids this third-party libraries management confusion by keeping all libraries in a central place for each operating system. Regardless of your project count, the third-party libraries will be downloaded to the system only once.

Whenever you add a third-party library to your POM dependency, the specified JAR and related files will be copied into the location \.m2\repository.

We will learn about the Maven dependency structure by looking at one sample. Let's assume that we need to use Log4j version 2.9.1 in our application. In order to use it, we need to add the dependency to our project. We can search the log4j-core dependency from https://mvnrepository.com and copy the dependency into our POM under dependencies.

A sample Maven dependency is as follows: