Read & Write files from S3

Preamble

This tutorial helps you to upload and download a file on a AWS S3 bucket.

Before start this tutorial be sure you have these prerequisites :

• A S3 bucket
• A file on the bucket
• An AWS access key and secret key
• Java SDK 8 or above

Maven dependencies

<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk</artifactId>
    <optional>false</optional>
    <version>1.12.77</version>
</dependency>
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-core</artifactId>
    <optional>false</optional>
    <version>1.12.77</version>
</dependency>

Libraries

import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.GetObjectRequest;
import java.io.*;

Connection

This connection use accessKeyId and secretAccessKey. In Saagie environment it could be better to use environment variables.

BasicAWSCredentials awsCreds = new BasicAWSCredentials("AKIKYUEMVKZ92EH92DCH", "passwordpasswordpasswordpasswordpassword");
s3Client = AmazonS3ClientBuilder.standard()
    .withRegion("eu-west-3")
    .withCredentials(new AWSStaticCredentialsProvider(awsCreds))
    .build();

Write a file

s3Client.putObject("saagie-service", "documentation-s3/doc-java/s3File.txt", new File("e:/s3File.txt"));

Read a file

s3Client.getObject("saagie-service", "documentation-s3/doc-java/s3File.txt", new File("e:/s3File.txt"));