Maven Install Dependencies

Introduction to Maven Install Dependencies

Maven install dependencies are required in the maven project. Maven contains a good mechanism for describing dependencies in our project, by using simple elements of XML. The pom.xml file of maven is used to download the dependencies. The installed dependencies are used by maven at the time of code compilation for direct dependent classes which were available for the compiler. Maven dependencies are required to run the project of maven.

Key Takeaways

• Basically, there are two types of dependencies available in maven i.e. transitive and direct. The direct dependencies are nothing but which was explicitly included in the project.
• The transitive dependencies are required in the direct dependencies, maven is automatically included in the required dependencies of transitive in a specified project.

Overview of Maven Install Dependencies

To install the dependencies of maven we need to execute the mvn dependency command which will install all the dependencies. We can use the maven dependency plugin for downloading the dependencies. We can change the target location by setting the property of the output directory. We are running mvn dependency with copy dependency for downloading all the dependencies.

We can also use the intellij idea for adding maven dependency in our project. Maven easily include the third-party dependencies in our project, which was equivalent to the other languages like PHP or ruby. By using maven we can build the java project with the classes. Maven will be expecting the structure of the directory from the java source code.

How to Download Maven Install Dependencies?

Below steps shows how we can download the maven install dependencies as follows:

1. While downloading the maven install dependencies we are creating the template of the project by using spring initializer. Below we are creating the template of maven install dependencies by using spring initializer.

Group name – com.example
Artifact – maven_dependencies
Name – maven_dependencies
Packaging – jar
Java version – 8
Language – java

After creating the template of maven install dependencies into spring initializer now, we need to download and extract the project template.

2. In this step we are checking the project structure and pom.xml file. The project structure is as follows.

3. In the below example we are adding the maven dependencies which we require in our project into the pom.xml file as follows.

Code:

<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>
<dependency>
  <groupId> junit </groupId>
  <artifactId> junit </artifactId>
  <version> 4.12 </version>
  <scope> test </scope>
</dependency>

Output:

4. After adding the dependency in the below example we are opening the terminal where our pom.xml file is located. After opening the terminal we are executing the following command as follows.

Code:

mvn dependency:copy-dependencies

Output:

5. In the above example we can see that all the dependencies are downloaded and copied into the target folder. After executing the above command we can see that all the dependency is installed into the target/dependency folder. In the below example, we can see that all the dependency is downloaded in the specified folder as follows.

How to Install Dependencies for Maven?

In the below example we are installing junit dependencies for maven as follows. For installing the junit dependency we need to add the dependency into the pom.xml file. We are adding the junit dependency into the pom.xml file as follows.

Code:

<dependency>
  <groupId> junit </groupId>
  <artifactId> junit-maven </artifactId>
  <version> 4.12 </version>
  <scope> maven-test </scope>
</dependency>

Output:

After adding the dependency we are executing the below command to install the dependencies for maven as follows. First, it will download the dependencies then all dependencies are copied to the specified directory.

Code:

mvn dependency:copy-dependencies

Output:

In the below example, we are downloading and installing the dependency into the specified location. We can see that we are downloading the dependency in /mnt/c/dependency location as follows.

Code:

mvn dependency:copy-dependencies –DoutputDirectory = /mnt/c/dependency

Output:

After downloading and installing the dependency we can check that specified location where our dependency file is generated as follows.

Maven Dependencies for Scope

Dependency scope helps us to limit the transitivity dependency. It is modifying the classpath for the different task build. Below is the default scope where no other scope is provided.

Code:

<dependency>
  <groupId> commons-lang </groupId>
  <artifactId> commons-lang </artifactId>
  <version> 2.6 </version>
</dependency>

Output:

The provided scope is used to mark the dependencies which was provided at runtime by the container of JDK. Below example of provided scope is as follows.

Code:

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

Output:

The dependency with runtime scope is required at runtime. But we have not required the same at compile time as follows.

Code:

<dependency>
  <groupId> mysql </groupId>
  <artifactId> mysql-connector-java </artifactId>
  <version> 8.0.28 </version>
  <scope> runtime </scope>
</dependency>

Output:

We use the test scope for indicating the specified dependency is not required while runtime.

Code:

<dependency>
  <groupId> junit </groupId>
  <artifactId> junit </artifactId>
  <version> 4.12 </version>
  <scope> test </scope>
</dependency>

Output:

The scope of the system is similar to the provided scope. The system scope requires a direct point.

Code:

<dependency>
  <groupId> com.baeldung </groupId>
  <artifactId> custom-dependency </artifactId>
  <version> 1.3.2 </version>
  <scope> system </scope>
  ……
</dependency>

Output:

Import Maven Dependencies

Import will indicate that the dependency will be replaced with the effective dependency which was declared in a POM. In the below example, we are replacing the custom project dependency in a pom.xml file.

Code:

<dependency>
  <groupId> com.baeldung </groupId>
  <artifactId> custom-project </artifactId>
  <version> 1.3.2 </version>
  <type> pom </type>
  <scope> import </scope>
</dependency>

Output:

After adding the dependency, we need to go into the project folder and need to execute the mvn clean install command for importing the dependency which we have added. In the below example, we are running this command from the command line.

Code:

mvn clean install

Output:

In the below example we are importing the maven dependencies using the spring tool suite.

Conclusion

To install the dependencies of maven we need to execute the mvn dependency command which will install all the dependencies. Maven contains a good mechanism for describing dependencies in our project, by using simple elements of XML. The pom.xml file of maven is used to download the dependencies.

Recommended Articles

This is a guide to Maven Install Dependencies. Here we discuss the introduction, and how to download maven install dependencies. and maven dependencies for scope. You may also have a look at the following articles to learn more –

1. Maven Build Command
2. Maven WAR Plugin
3. Maven Profile
4. Maven Versions