Using Amazon Web Services S3 in Play Framework Model class

S3Resource.java

package models;

import play.db.ebean.Model;

import java.io.File;
import java.util.UUID;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;

import com.amazonaws.HttpMethod;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.GetObjectRequest;

/**
 * @author <a href="mailto:dev@alexander-hanschke.de">Alexander Hanschke</a>
 */
@Entity
@Table(name = "s3_resource")
public class S3Resource extends Model {

    public static AmazonS3 s3;
    public static String s3Bucket;

    @Id
    public Long id;

    public String key;
    public String url;
    public String name;
    public String bucket;

    @Transient
    public File content;

    public static Finder<Long, S3Resource> find = new Finder<Long, S3Resource>(Long.class, S3Resource.class);

    public static S3Resource findByKey(String key) {
        return
            find.where()
                .eq("key", key)
                .findUnique();
    }

    @Override
    public void save() {
        store();
        super.save();
    }

    @Override
    public void save(String server) {
        store();
        super.save(server);
    }

    @Override
    public void delete() {
        remove();
        super.delete();
    }

    @Override
    public void delete(String server) {
        remove();
        super.delete(server);
    }

    private void store() {
        this.key = UUID.randomUUID().toString();
        this.bucket = s3Bucket;

        if (this.content != null) {
            s3.putObject(new PutObjectRequest(this.bucket, this.key, this.content));
            this.url = s3.generatePresignedUrl(this.bucket, this.key, null, HttpMethod.GET).toString();
            this.name = this.content.getName();
        }
    }

    private void remove() {
        s3.deleteObject(this.bucket, this.key);
    }

}