Amazon recommends using a properties file to supply AWS credentials to your Java application, and while this is generally the most appropriate way to do it, what happens if you want to dynamically connect to different AWS accounts, or for whatever reason you need to provide the credentials in code?

The solution to this is to implement the AWSCredentials interface and override the getAWSAccessKeyId() and getAWSSecretKey() methods, like so:

public class AWSCredentialProvider implements AWSCredentials {

    @Override
    public String getAWSAccessKeyId() {
        return "AWS-Access-Key";
    }

    @Override
    public String getAWSSecretKey() {
        return "AWS-Secret-Key";
    }

}

Because this is a Java class, you can obtain and return the keys however you like. When it comes time to create an AWS client, such as an AmazonEC2Client for example, you just pass an instance of AWSCredentialProvider:

AmazonEC2Client ec2Client = new AmazonEC2Client(new AWSCredentialProvider())