What is pom.xml (Project Object Model)? Sample pom.xml for you to use in your Dynamic Web Project (Java / J2EE)

What is pom.xml file?

POM means Project Object Model. It is a fundamental unit of work in Maven. pom.xml file contains all configuration, dependencies, plugin integration and project setup instructions.

This is the best way to add any library dependencies into your project. Copying .jar files into your project resource folder is a old way of doing it

Let’s understand pom.xml file in details.

Simplest default pom.xml file

<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.crunchify.tutorials</groupId>
    <artifactId>crunchify-tutorials</artifactId>
    <version>1.0.1-SNAPSHOT</version>

</project>

Let’s go over pom.xml Elements:

Element	Description
project	The element is the root of the descriptor. The following table lists all of the possible child elements.
modelVersion	Declares to which version of project descriptor this POM conforms. Set it version 4.0.0.
groupId	A universally unique identifier for a project. It is normal to use a fully-qualified package name to distinguish it from other projects with a similar name (eg. org.apache.maven).
artifactId	The identifier for this artifact that is unique within the group given by the group ID. An artifact is something that is either produced or used by a project. Examples of artifacts produced by Maven for a project include: JARs, source and binary distributions, and WARs.
version	The current version of the artifact produced by this project.

understand pom.xml elements

pom.xml file with additional elements

pom.xml file with more elements:

<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.crunchify.tutorials</groupId>
    <artifactId>crunchify-tutorials</artifactId>
    <version>1.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>  
  
  <name>Crunchify's Java Tutorials</name>  
  <url>https://crunchify.com</url>  
  
     <build>
        <sourceDirectory>src</sourceDirectory>
        <finalName>crunchify-tutorial</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>15</source>
                    <target>15</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

  <dependencies>  
        <dependency>
            <groupId>org.glassfish</groupId>
            <artifactId>javax.json</artifactId>
            <version>1.0.4</version>
        </dependency>
        <dependency>
            <groupId>com.github.wnameless</groupId>
            <artifactId>json-flattener</artifactId>
            <version>0.2.2</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.10.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.10</version>
        </dependency>
  </dependencies>  
</project>

Element	Description
packaging	The type of artifact this project produces, for example jar war ear pom. Plugins can create their own packaging, and therefore their own packaging types, so this list does not contain all possible types.
name	The full name of the project.
url	The URL to the project’s homepage.
dependencies	This element describes all of the dependencies associated with a project. These dependencies are used to construct a classpath for your project during the build process. They are automatically downloaded from the repositories defined in this project.
dependency	The project group that produced the dependency, e.g. org.apache.maven.
build	Information required to build the project.
sourceDirectory	This element specifies a directory containing the source of the project. The generated build system will compile the source in this directory when the project is built. The path given is relative to the project descriptor.
finalName	The filename (excluding the extension, and with no path information) that the produced artifact will be called. The default value is ${artifactId}-${version}.
plugins	The list of plugins to use.
plugin	The group ID of the plugin in the repository.
scope	The scope of the dependency – compile, runtime, test, system, and provided. Used to calculate the various classpaths used for compilation, testing, and so on. It also assists in determining which artifacts to include in a distribution of this project.

We have published more than 700 Java tutorials on Crunchify, and we are using pom.xml files since beginning including Spring MVC dependencies.

Over the last few years because of adding more and more library dependencies, Crunchify’s Java tutorial pom.xml file is more bigger now

Here is our current pom.xml file for your reference. If you copy and add it to your project then that works for you too.

pom.xml file we are using for Crunchify’s Java totorials

<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.crunchify.tutorials</groupId>
    <artifactId>crunchify-tutorials</artifactId>
    <version>1.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>Crunchify's Java Tutorials</name>
    <url>https://crunchify.com</url>

    <build>
        <sourceDirectory>src</sourceDirectory>
        <finalName>crunchify-tutorial</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>15</source>
                    <target>15</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.3.1</version>
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.5.3</version>
                <configuration>
                    <descriptors>
                        <descriptor>src/assembly/crunchify.xml</descriptor>
                    </descriptors>
                </configuration>
            </plugin>
        </plugins>
        <pluginManagement>
            <plugins>
                <!--This plugin's configuration is used to store Eclipse m2e settings
                    only. It has no influence on the Maven build itself. -->
                <plugin>
                    <groupId>org.eclipse.m2e</groupId>
                    <artifactId>lifecycle-mapping</artifactId>
                    <version>1.0.0</version>
                    <configuration>
                        <lifecycleMappingMetadata>
                            <pluginExecutions>
                                <pluginExecution>
                                    <pluginExecutionFilter>
                                        <groupId>
                                            org.apache.maven.plugins
                                        </groupId>
                                        <artifactId>
                                            maven-compiler-plugin
                                        </artifactId>
                                        <versionRange>
                                            [3.1,)
                                        </versionRange>
                                        <goals>
                                            <goal>compile</goal>
                                        </goals>
                                    </pluginExecutionFilter>
                                    <action>
                                        <ignore/>
                                    </action>
                                </pluginExecution>
                                <pluginExecution>
                                    <pluginExecutionFilter>
                                        <groupId/>
                                        <artifactId/>
                                        <versionRange>[3.1,)</versionRange>
                                        <goals>
                                            <goal/>
                                        </goals>
                                    </pluginExecutionFilter>
                                    <action>
                                        <ignore/>
                                    </action>
                                </pluginExecution>
                            </pluginExecutions>
                        </lifecycleMappingMetadata>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.glassfish</groupId>
            <artifactId>javax.json</artifactId>
            <version>1.1.4</version>
        </dependency>
        <dependency>
            <groupId>com.github.wnameless.json</groupId>
            <artifactId>json-flattener</artifactId>
            <version>0.12.0</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.10.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.7</version>
        </dependency>
        <dependency>
            <groupId>net.jodah</groupId>
            <artifactId>expiringmap</artifactId>
            <version>0.5.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.13</version>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20210307</version>
        </dependency>
        <dependency>
            <groupId>net.spy</groupId>
            <artifactId>spymemcached</artifactId>
            <version>2.12.3</version>
        </dependency>
        <dependency>
            <groupId>com.whalin</groupId>
            <artifactId>Memcached-Java-Client</artifactId>
            <version>3.0.2</version>
        </dependency>
        <dependency>
            <groupId>com.googlecode.xmemcached</groupId>
            <artifactId>xmemcached</artifactId>
            <version>2.4.7</version>
        </dependency>
        <dependency>
            <groupId>com.paypal.sdk</groupId>
            <artifactId>rest-api-sdk</artifactId>
            <version>LATEST</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>javax.ws.rs</groupId>
            <artifactId>javax.ws.rs-api</artifactId>
            <version>2.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-all</artifactId>
            <version>1.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.14.1</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>30.1.1-jre</version>
        </dependency>
        <dependency>
            <groupId>com.googlecode.json-simple</groupId>
            <artifactId>json-simple</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>commons-net</groupId>
            <artifactId>commons-net</artifactId>
            <version>3.8.0</version>
        </dependency>

        <dependency>
            <groupId>org.ow2.asm</groupId>
            <artifactId>asm</artifactId>
            <version>9.1</version>
        </dependency>
        <dependency>
            <groupId>axis</groupId>
            <artifactId>axis</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.9.4</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-collections4</artifactId>
            <version>4.4</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-configuration2</artifactId>
            <version>2.7</version>
        </dependency>

        <dependency>
            <groupId>commons-discovery</groupId>
            <artifactId>commons-discovery</artifactId>
            <version>0.5</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging-api</artifactId>
            <version>1.1</version>
        </dependency>
        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>javax.mail-api</artifactId>
            <version>1.6.2</version>
        </dependency>

        <dependency>
            <groupId>javax.xml</groupId>
            <artifactId>jaxrpc-api</artifactId>
            <version>1.1</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.axis</groupId>
            <artifactId>axis-saaj</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>wsdl4j</groupId>
            <artifactId>wsdl4j</artifactId>
            <version>1.6.3</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.4.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-compress</artifactId>
            <version>1.20</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.25</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.8.0-M1</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.3.0-alpha5</version>
        </dependency>
        <dependency>
            <groupId>commons-validator</groupId>
            <artifactId>commons-validator</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.8</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>5.3.8</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.31</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jul-to-slf4j</artifactId>
            <version>1.7.31</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>1.7.31</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>log4j-over-slf4j</artifactId>
            <version>1.7.31</version>
        </dependency>

    </dependencies>
</project>

I hope this clarifies what is pom.xml file and why we use it in any Java’s J2EE project. Let me know if you have any more questions.

The post What is pom.xml (Project Object Model)? Sample pom.xml for you to use in your Dynamic Web Project (Java / J2EE) appeared first on Crunchify.