The basics of Eclipse and Maven

Eclipse is an IDE for multiple programming languages, such as Java, C++, and Python. Eclipse contains different perspectives for your needs. A perspective is a set of views and editors in the Eclipse workbench. The following screenshot shows common perspectives for Java development:

On the left-hand side, we have Project Explorer, where we can see our project structure and resources. Project Explorer is also used to open files by double-clicking on them. The files will be opened in the editor, which is located in the middle of the workbench. The Console view can be found in the lower section of the workbench. The Console view is really important because it shows application logging messages.

You can get Spring Tool Suite (STS) for Eclipse if you want, but we are not going to use it in this book, because the plain Eclipse installation is enough for our purposes. STS is a set of plugins that makes Spring application development simpler (https://spring.io/tools).

Apache Maven is a software project management tool. The basis of Maven is the Project Object Model (POM). Maven makes the software development process simpler and it also unifies the development process. You can also use another project management tool, called Gradle, with Spring Boot, but in this book, we will focus on using Maven.

The POM is a pom.xml file that contains basic information about the project. There are also all the dependencies that Maven should download to be able to build the project.

Basic information about the project can be found at the beginning of the pom.xml file, which defines, for example, the version of the application, packaging format, and so on.

The minimum version of the pom.xml file should contain the project root, modelVersion, groupId, artifactId, and version.

Dependencies are defined in the dependencies section, as follows:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.packt</groupId>
  <artifactId>cardatabase</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>cardatabase</name>
  <description>Demo project for Spring Boot</description>
  
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.3.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

Maven is normally used from the command line. Eclipse contains embedded Maven, and that handles all the Maven operations we need. Therefore, we are not focusing on Maven command-line usage here. The most important thing is to understand the structure of the pom.xml file and how to add new dependencies to it.