Setting up an Apache Maven project

You can use Apache Maven to set up and build AWS SDK for Java projects, or to build the SDK itself.

Prerequisites

To use the AWS SDK for Java with Maven, you need the following:

• Java 8.0 or later. You can download the latest Java SE Development Kit software from http://www.oracle.com/technetwork/java/javase/downloads/. The AWS SDK for Java also works with OpenJDK and Amazon Corretto, a distribution of the Open Java Development Kit (OpenJDK). Download the latest OpenJDK version from https://openjdk.java.net/install/index.html. Download the latest Amazon Corretto 8 or Amazon Corretto 11 version from the Corretto page.

• Apache Maven. If you need to install Maven, go to http://maven.apache.org/ to download and install it.

Create a Maven project

To create a Maven project from the command line, open a terminal or command prompt window, enter or paste the following command, and then press Enter or Return.

mvn -B archetype:generate \
 -DarchetypeGroupId=software.amazon.awssdk \
 -DarchetypeArtifactId=archetype-lambda -Dservice=s3 -Dregion=US_WEST_2 \
 -DgroupId=com.example.myapp \
 -DartifactId=myapp

Note

Replace com.example.myapp with the full package namespace of your application. Also replace myapp with your project name. This becomes the name of the directory for your project.

This command creates a Maven project using the AWS Lambda project archetype. This project archetype is preconfigured to compile with Java SE 8 and includes a dependency to the AWS SDK for Java.

For more information about creating and configuring Maven projects, see the Maven Getting Started Guide.

Configure the Java compiler for Maven

If you created your project using the AWS Lambda project archetype as described earlier, this is already done for you.

To verify that this configuration is present, start by opening the pom.xml file from the project folder you created (for example, myapp) when you executed the previous command. Look on lines 11 and 12 to see the Java compiler version setting for this Maven project, and the required inclusion of the Maven compiler plugin on lines 71-75.

<project>
  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>${maven.compiler.plugin.version}</version>
      </plugin>
    </plugins>
  </build>
</project>

If you create your project with a different archetype or by using another method, you must ensure that the Maven compiler plugin is part of the build and that its source and target properties are both set to 1.8 in the pom.xml file.

See the previous snippet for one way to configure these required settings.

Alternatively, you can configure the compiler configuration inline with the plugin declaration, as follows.

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Declare the SDK as a dependency

To use the AWS SDK for Java in your project, you need to declare it as a dependency in your project’s pom.xml file.

If you created your project using the project archetype as described earlier, the SDK is already configured as a dependency in your project. We recommend that you update this configuration to reference the latest version of the AWS SDK for Java. To do so, open the pom.xml file and change the aws.java.sdk.version property (on line 16) to the latest version. The following is an example.

<project>
  <properties>
    <aws.java.sdk.version>2.16.1</aws.java.sdk.version>
  </properties>
</project>

Find the latest version of the AWS SDK for Java in the AWS SDK for Java API Reference version 2.x.

If you created your Maven project in a different way, configure the latest version of the SDK for your project by ensuring that the pom.xml file contains the following.

<project>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>software.amazon.awssdk</groupId>
        <artifactId>bom</artifactId>
        <version>2.X.X</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>
</project>

Note

Replace 2.X.X in the pom.xml file with a valid version of the AWS SDK for Java version 2.

Set dependencies for SDK modules

Now that you have configured the SDK, you can add dependencies for one or more of the AWS SDK for Java modules to use in your project.

Although you can specify the version number for each component, you don’t need to because you already declared the SDK version in the dependencyManagement section. To load a custom version of a given module, specify a version number for its dependency.

If you created your project using the project archetype as described earlier, your project is already configured with multiple dependencies. These include dependences for Lambda and Amazon DynamoDB, as follows.

<project>
  <dependencies>
    <dependency>
      <groupId>software.amazon.awssdk</groupId>
      <artifactId>dynamodb</artifactId>
    </dependency>
    <dependency>
      <groupId>com.amazonaws</groupId>
      <artifactId>aws-lambda-java-core</artifactId>
      <version>1.2.0</version>
    </dependency>
  </dependencies>
</project>

Add the modules to your project for the AWS service and features you need for your project. The modules (dependencies) that are managed by the AWS SDK for Java BOM are listed on the Maven central repository (https://mvnrepository.com/artifact/software.amazon.awssdk/bom/latest).

Note

You can look at the pom.xml file from a code example to determine which dependencies you need for your project. For example, if you’re interested in the dependencies for the Amazon S3 service, see {url-awsdocs-github}aws-doc-sdk-examples/blob/master/javav2/example_code/s3/src/main/java/com/example/s3/S3ObjectOperations.java[this example] from the AWS Code Examples Repository on GitHub. (Look for the pom.xml file file under {url-awsdocs-github}aws-doc-sdk-examples/blob/master/javav2/example_code/s3/pom.xml[/java2/example_code/s3].)

Build the entire SDK into your project

To optimize your application, we strongly recommend that you pull in only the components you need instead of the entire SDK. However, to build the entire AWS SDK for Java into your project, declare it in your pom.xml file, as follows.

<project>
  <dependencies>
    <dependency>
      <groupId>software.amazon.awssdk</groupId>
      <artifactId>aws-sdk-java</artifactId>
      <version>2.X.X</version>
    </dependency>
  </dependencies>
</project>

Build your project

After you configure the pom.xml file, you can use Maven to build your project.

To build your Maven project from the command line, open a terminal or command prompt window, navigate to your project directory (for example, myapp), enter or paste the following command, then press Enter or Return.

mvn package

This creates a single .jar file (JAR) in the target directory (for example, myapp/target). This JAR contains all of the SDK modules you specified as dependencies in your pom.xml file.