Convert a Java project to Maven project in IntelliJ IDEA

This article shows how to convert a Java project to a Maven project in IntelliJ IDEA.

Table of contents

• 1. A Non-Maven Project
• 2. Add Framework Support – Maven
• 3. Update the default pom.xml
• 4. Reload the Maven project
• 5. References

P.S Tested with IntelliJ IDEA 2021.1.1

1. A Non-Maven Project

A non-Maven project (without pom.xml), but the directory structure follows the Maven standard directory.

• src/main/java
• src/main/resources
• src/test/java
• src/test/resources

Later we will convert the above non-Maven project into a Java project support Maven features in IntelliJ IDEA.

2. Add Framework Support – Maven

Right clicks on the project name, clicks Add Framework Support..., and then selects Maven.

3. Update the default pom.xml

3.1 The IntelliJ IDEA will generate a default pom.xml and configure the project to support Maven.

This is the default pom.xml

<?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>groupId</groupId>
    <artifactId>jersey-jetty</artifactId>
    <version>1.0-SNAPSHOT</version>

</project>

3.2 We should update the pom.xml by adding dependencies and plugins. The below updated pom.xml adds support for Java 11, and JUnit 5 for testing.

<?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.mkyong</groupId>
    <artifactId>jersey-jetty</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <java.version>11</java.version>
        <junit.version>5.4.0</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-params</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <finalName>project name</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

4. Reload the Maven project

4.1 If the Maven view is hidden, we can reopen it by selecting the View -> Tool Windows -> Maven

4.2 Clicks the reload Maven project icon to reload everything.

IntelliJ IDEA should configure the project to support Maven features automatically, done.

5. References

• Maven standard directory
• Maven in IntelliJ IDEA
• How to attach JDK source code to IntelliJ IDEA?