Java AWS S3 Presigned URI Example

presignedUriMethod.java

package ...;

import com.amazonaws.HttpMethod;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

import java.net.URL;
import java.nio.file.FileAlreadyExistsException;
import java.util.Date;

public abstract class PresignedURIMethods {
	public static final Logger LOG = LogManager.getLogger(PresignedURIMethods.class);

	//method for downloading objects
	public static URL generatePresignedUrlGetObject(AmazonS3Client amazonS3Client, String bucketName, String objectKey, S3PresignedUrlExpiration s3PresignedUrlExpirationTime) {
		LOG.debug("generate presigned url get object " + objectKey + " from bucket " + bucketName);

		Date expirationDate = s3PresignedUrlExpirationTime.getExprationDate();
		GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(bucketName, objectKey).withMethod(HttpMethod.GET).withExpiration(expirationDate);
		URL url = amazonS3Client.generatePresignedUrl(generatePresignedUrlRequest);

		LOG.debug("generated presigned url " + url.toString());

		return url;
	}

	//method for uploading / update objects
	public static URL generatePresignedUrlPutObject(AmazonS3Client amazonS3Client, String bucketName, String filePath, boolean overwriteIfAlreadyExist)
			throws FileAlreadyExistsException {
		LOG.debug("generate presigned url put object to path " + filePath + " in bucket " + bucketName);

		Date expirationDate = S3PresignedUrlExpiration.PURI_UPLOAD_FILE.getExprationDate();
		if(!overwriteIfAlreadyExist && amazonS3Client.doesObjectExist(bucketName, filePath)) {
			LOG.warn("Bucket fie, exists and should not be overwritten: " + filePath);
			throw new FileAlreadyExistsException(MessageConstants.S3_FILE_EXISTS_MESSAGE);
		}

		GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(bucketName, filePath).withMethod(HttpMethod.PUT).withExpiration(expirationDate);

		return amazonS3Client.generatePresignedUrl(generatePresignedUrlRequest);
	}


	public static boolean doesDocumentExistInS3(AmazonS3Client amazonS3Client, String bucketName, String objectKey) {
		return amazonS3Client.doesObjectExist(bucketName, objectKey);
	}

}

S3PresignedUrlExpirationEnum.java

import java.util.Date;

public enum S3PresignedUrlExpiration {
    PURI_UPLOAD_FILE(1000 * 2), PURI_READ_FILE(1000 * 1);

    private final long expirationTime;

    S3PresignedUrlExpiration(long expirationTime) {
        this.expirationTime = expirationTime;
    }

    public long getExpirationTime() {
        return expirationTime;
    }

    public Date getExprationDate(){
        Date date = new Date();
        long expirationTimeLong = date.getTime() + expirationTime;
        date.setTime(expirationTimeLong);
        return date;
    }

    public long getExprationTimestampAsSeconds(){
        Date date = new Date();
        long expirationTimeLong = date.getTime() + expirationTime;
        return expirationTimeLong/1000;
    }
}

S3 Maven Import
<!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-s3 --> <dependency> <groupId>com.amazonaws</groupId> <artifactId>aws-java-sdk-s3</artifactId> <version>1.11.483</version> </dependency>