Expert AWS Development

Please perform the following steps to include AWS SDK for Java using Apache Maven.

mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-quickstart

You will see the pom.xml file generated under the ..\AWS SDK Example\java-maven-demo folder.

Configuring an SDK as a Maven dependency

Please perform the following steps to configure AWS SDK as Maven dependency.

1. To add AWS SDK for Java in your project, you need to add the dependency to the pom.xml file. From SDK version 1.9.*, you can import single or individual components. If you want to add the entire SDK as a dependency, add the following code in the <dependency> tag in the pom.xml file:

  <dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk</artifactId>
    <version>1.11.106</version>
  </dependency>

2. If you are using SDK Version 1.9.* or above, you can import many individual components, such as EC2, S3, CodeCommit, or CodeDeploy:

  <dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-s3</artifactId>
  </dependency>

3. After setting up the pom.xml file, you can build your project with the mvn package command. It will generate a Java Archive (JAR) file in the target directory after successful execution:

4. Now you need to add the following code in the pom.xml file to connect with the AWS SDK. You have to mention your main Java class under the Configuration | mainClass tag. We will create the S3MavenExample.java file in the next step:

<build>
       <resources>
           <resource>
               <directory>${env.HOME}/.aws/</directory>
           </resource>
       </resources>
       <plugins>
           <plugin>
               <groupId>org.codehaus.mojo</groupId>
               <artifactId>exec-maven-plugin</artifactId>
               <version>1.2.1</version>
               <executions>
                   <execution>
                       <goals>
                           <goal>java</goal>
                       </goals>
                   </execution>
               </executions>
               <configuration>
              <mainClass>com.packt.example.S3MavenExample</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>

5. Let's create the S3MavenExample.java file in the com/packt/example package. We are going to create an S3 bucket as per the specific region with a random number generator, prefix it with s3-maven-bucket-, and then delete the bucket:

import java.util.UUID;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;

6. You have imported UUID to generate the pseudo random number. You are importing Region and Regions to create the bucket in a specific region, and AmazonS3 and AmazonS3Client to access the AWS S3 services:

AmazonS3 s3 = new AmazonS3Client();
Region s3Region = Region.getRegion(Regions.AP_SOUTHEAST_1);
s3.setRegion(s3Region);

7. Here you are creating an S3 client and specifying the specific region where it will create the bucket:

Note

If you do not specify any region, it will create it at US East (N. Virginia). This means the default region is US East (N. Virginia).

String bucketName = "s3-maven-bucket-" + UUID.randomUUID();

8. Here you are creating the s3-maven-bucket- prefix with some random UUID:

s3.createBucket(bucketName);

9. To create the bucket, you can use createBucket() method. You have to pass the bucket name as a parameter in this method:

s3.deleteBucket(bucketName);

10. To delete the bucket, you can use the deleteBucket() method. You have to pass the bucket name as a parameter in this method. After creating the Java file, execute the following command:

mvn clean compile exec:java

It will create and delete the bucket as per the specified regions:

If you have completed this step and you can see the creation and deletion of the bucket, it means you have successfully completed AWS SDK for Java using Maven in your project.

Please perform the following steps to include AWS SDK for Java using Gradle:

gradlew.bat

After completing this execution, you can see the .gradle folder.

apply plugin: 'java'
apply plugin: 'application'

mainClassName="com.packt.example.S3GradleExample"
repositories {
    mavenCentral()
}
dependencies {
    compile 'com.amazonaws:aws-java-sdk:1.9.6'
}

package com.packt.example;
import java.util.UUID;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
public class S3GradleExample {
    public static void main(String[] args) {
        AmazonS3 s3 = new AmazonS3Client();
        Region s3Region = Region.getRegion(Regions.AP_SOUTHEAST_1);
        s3.setRegion(s3Region);
       String bucketName = "s3-gradle-bucket-" + UUID.randomUUID();
        System.out.println("Amazon S3 will create/delete bucket");
        // Create a new bucket
        System.out.println("Creating bucket " + bucketName + "\n");
        s3.createBucket(bucketName);
        // Delete a bucket.
        System.out.println("Deleting bucket " + bucketName + "\n");
        s3.deleteBucket(bucketName);
    }
}

gradlew clean build run

It will create and delete the bucket as per the specified regions:

I am assuming that you have already installed Eclipse 4.4 (Luna) or a higher version on your machine as the AWS toolkit supports that.

There are two ways to install an AWS toolkit in your IDE:

We will install using the first method. Now please perform the following steps and refer to the following screenshot:

So far, you have learned how to add the AWS Java toolkit into your project using Maven, Gradle, and Eclipse IDE. Now we will see how to add the AWS SDK for Node.js into your project.

For Android, AWS provides an open source SDK that is distributed under an Apache license. This will provide libraries, code examples, and documentation to develop mobile applications using AWS.

Currently, AWS supports the following services for AWS Mobile SDK for Android:

Now let's understand how to set up the AWS Mobile SDK and then we will see an example with Amazon S3.

The AWS Mobile SDK is available at the following two resources for download:

This SDK includes class libraries, code example, and documentation:

In the next section, you will see how to set up AWS Mobile SDK for Android.

Configuring AWS Mobile SDK for Android

Let's start configuring AWS Mobile SDK for Android in the following three ways:

• Using Maven: Apache Maven is a build automation and dependency management tool, which contains a pom.xmlfile for configurations. It is used to mention the specific Amazon web service which you will use in the project instead of the entire SDK.

Note

Amazon Mobile SDK for Android v 2.1.3 or above supports Maven.

In the pom.xml file, you have to add a <dependency> element in which you have to add three subelements such as groupid, artifactid, and version.

groupid will be the same as com.amazonaws for all AWS services.

In artifactid, you have to mention the appropriate service which you are using in your applications.

In version, you have to mention the acceptable AWS Mobile SDK version for Android for the given dependency:

• Using Gradle: When using Android Studio, you can add additional individual services with aws-android-sdk-core services as a dependency in your build.gradle file:

        

Note

Avoid + in version numbers. Use com.amazonaws:aws-android-sdk-core:#.#.# instead of com.amazonaws:aws-android-sdk-core:#.#.+.

• Import JAR files: As mentioned previously, you can download the AWS Mobile SDK from the AWS website or GitHub and use it into your project.

In Android Studio, you can add the AWS Mobile SDK JAR file in your application by dragging it into the Project View. You can also add the individual JAR file for your services. It will add it to the build path automatically. Then use the Gradle file to sync your project.   

Note

Set a permission in the Android manifest file. In your AndroidManifest.xml file, you need to set the following permission: <uses-permission android:name="android.permission.INTERNET" />.

You have to use Amazon Cognito Identity Provider to obtain AWS credentials. Those credentials you can use in your mobile application to access AWS services. You can also set user-specific permissions to access particular AWS services. You don't have to embed personal credentials. Amazon Cognito will be covered in more detail in Chapter 6, User Authentication with AWS Cognito.

So far, we have covered AWS SDK for IoT and AWS Mobile SDK for Android. Let's explore an example for the Transfer Utility to consume Amazon S3 services. Here we will upload a file from a mobile device and download a file to a mobile device. We will use Android Studio, Amazon Cognito, Amazon S3, and Amazon IAM. Please perform the following steps:

compile 'com.amazonaws:aws-android-sdk-core:2.6.6'
compile 'com.amazonaws:aws-android-sdk-cognito:2.6.6'
compile 'com.amazonaws:aws-android-sdk-s3:2.6.6'

<service android:name="com.amazonaws.mobileconnectors.s3.transferutility.TransferService"
android:enabled="true" />

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACTION_DOWN"/>
<uses-permission android:name="android.permission.SMARTBONDING_FEATURE_ENABLED" />

{
    "Version": "2012-10-17",
    "Statement": [{
        "Sid": "Stmt1510936216000",
        "Effect": "Allow",
        "Action": ["s3:*"],
        "Resource": ["arn:aws:s3:::<Bucket_Name>/*"]
    }]
}

<Button
    android:id="@+id/upload_file"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="File Upload to S3"
    android:onClick="uploadFile"/>

<Button
    android:id="@+id/downaload_file"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="File Download from S3"
    app:layout_constraintLeft_toRightOf="@id/upload_file"
    android:onClick="downloadFile"/>

import com.amazonaws.auth.CognitoCachingCredentialsProvider;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferObserver;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferUtility;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;

AmazonS3 s3Client;
TransferUtility transferUtility;
File uploadFilePath = new File(<FILE_UPLOAD_PATH>);
File downloadFilePath = new File(<FILE_DOWNLOAD_PATH);

getCognitoCredentials();
createTransferUtility();

Public void getCognitoCredentials(){
    CognitoCachingCredentialsProvider credentials

 = new CognitoCachingCredentialsProvider(
            getApplicationContext(),
            <Identity_Pool_ID>,
            Regions.<Your_Cognito_IdentityPool_Region>
    );
    createS3Client(credentials);
}

public void createS3Client(CognitoCachingCredentialsProvider credentials){
    s3 = new AmazonS3Client(credentials);
    s3.setRegion(Region.getRegion(Regions.US_EAST_1));
}

public void createTransferUtility(){
    transferUtility = new TransferUtility(s3, getApplicationContext());
}

public void uploadFile(View view){

    TransferObserver transferObserver = transferUtility.upload(
            "<S3_Bucket_Name>", 
            "<Upload_File_Key_Name>", 
            uploadFilePath 

    );
}

public void downloadFile(View view){

    TransferObserver transferObserver = transferUtility.download(
            "<S3_Bucket_Name>",

           "<Download_File_Key_Name>",
            downloadFilePath 
    );
}

When you tab on FILE UPLOAD TO S3, if the file is uploaded successfully, you can see it in your S3 bucket from the console:

 When you click on FILE DOWNLOAD FROM S3, if the file is downloaded successfully, you can see it in your folder or path: