<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:aws-context="http://www.springframework.org/schema/cloud/aws/context"
   xsi:schemaLocation="http://www.springframework.org/schema/cloud/aws/context http://www.springframework.org/schema/cloud/aws/context/spring-cloud-aws-context.xsd">
    <aws-context:context-credentials>
       <!-- ... -->
     </aws-context:context-credentials>
    <aws-context:context-resource-loader/>
</beans>

public class SimpleResourceLoadingBean {

@Autowired
private ResourceLoader resourceLoader;

public void writeResource() throws IOException {
        Resource resource = this.resourceLoader.getResource("s3://myBucket/rootFile.log");
        WritableResource writableResource = (WritableResource) resource;
        try (OutputStream outputStream = writableResource.getOutputStream()) {
            outputStream.write("test".getBytes());
        }
    }
}