sailing-analytics/wiki/s3-sample.md

S3 Controller

Here is a sample controller class that uploads a JPEG file from your local file system to your S3 Bucket.

Dependencies: http://aws.amazon.com/de/sdk-for-java/

package <you package>;

import com.amazonaws.AmazonClientException;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.ListObjectsRequest;
import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutObjectRequest;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectSummary;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class S3Controller {

    public static final String s3endpoint = "https://s3-eu-west-1.amazonaws.com/";
    
    public static final String profileImageBucket = "<your bucket>";
    
    private static final String accessKey = "<S3 access key>";

    private static final String secretKey = "<S3 secret key>";
   
    // put 
    public void put(String filename, String bucketName, File file)
            throws FileNotFoundException {
        AWSCredentials myCredentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3 s3 = new AmazonS3Client(myCredentials);
        PutObjectRequest putObject = new PutObjectRequest(bucketName, filename, file);
        ObjectMetadata metaData = new ObjectMetadata();
        metaData.setContentType("image/jpeg");
        metaData.setContentLength(file.length());
        putObject.setMetadata(metaData);
        s3.putObject(putObject);

    }

    // delete file
    public void delete(String fileName, String bucketName) {
        AWSCredentials myCredentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3 s3 = new AmazonS3Client(myCredentials);
        s3.deleteObject(bucketName, fileName);
    }

    // get a private file to local storage
    public void get(String fileName, String bucketName, File localFile) {
        AWSCredentials myCredentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3 s3 = new AmazonS3Client(myCredentials);
        try {
            S3Object object = s3.getObject(new GetObjectRequest(bucketName, fileName));
            InputStream inputStream = new BufferedInputStream(object.getObjectContent());
            try {
                try (OutputStream outputStream = new BufferedOutputStream(new FileOutputStream(localFile))) {
                    int read = -1;
                    while ((read = inputStream.read()) != -1) {
                        outputStream.write(read);
                    }
                    outputStream.flush();
                }
            } catch (IOException e) {
                e.printStackTrace(System.err);
            } finally {
                try {
                    inputStream.close();
                } catch (IOException e) {
                }
            }
        } catch (AmazonClientException e) {
        }
    }

    public boolean fileExists(String fileName, String bucketName) {
        AWSCredentials myCredentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3 s3 = new AmazonS3Client(myCredentials);
        ObjectListing objects = s3.listObjects(new ListObjectsRequest().withBucketName(bucketName).withPrefix(fileName));
        for (S3ObjectSummary objectSummary : objects.getObjectSummaries()) {
            if (objectSummary.getKey().startsWith(fileName)) {
                return true;
            }
        }
        return false;
    }
}