com.amazonaws.services.dynamodbv2.datamodeling

Class S3Link

java.lang.Object

com.amazonaws.services.dynamodbv2.datamodeling.S3Link

public class S3Link
extends Object

An S3 Link that works with DynamoDBMapper. An S3 link is persisted as a JSON string in DynamoDB. This link object can be used directly to upload/download files to S3. Alternatively, the underlying AmazonS3Client and TransferManager can be retrieved to provide full access API to S3.

For example:

 AWSCredentialsProvider s3CredentialProvider = ...;
 DynamoDBMapper mapper = new DynamoDBMapper(..., s3CredentialProvider);
 String username = "jamestkirk";
  
 User user = new User();
 user.setUsername(username);
  
 // S3 region can be specified, but is optional
 S3Link s3link = mapper.createS3Link("my-company-user-avatars", username + ".jpg");
 user.setAvatar(s3link);
  
 // All meta information of the S3 resource is persisted in DynamoDB, including
 // region, bucket, and key
 mapper.save(user);
  
 // Upload file to S3 with the link saved in DynamoDB
 s3link.uploadFrom(new File("/path/to/all/those/user/avatars/" + username + ".jpg"));
 // Download file from S3 via an S3Link
 s3link.downloadTo(new File("/path/to/downloads/" + username + ".jpg"));
  
 // Full S3 API is available via the canonical AmazonS3Client and TransferManager API.
 // For example:
 AmazonS3Client s3 = s3link.getAmazonS3Client();
 TransferManager s3m = s3link.getTransferManager();
 // etc.
 

The User pojo class used above:

 @DynamoDBTable(tableName = "user-table")
 public class User {
     private String username;
     private S3Link avatar;
  
     @DynamoDBHashKey
     public String getUsername() {
         return username;
     }
  
     public void setUsername(String username) {
         this.username = username;
     }
 
     public S3Link getAvatar() {
         return avatar;
     }
  
     public void setAvatar(S3Link avatar) {
         this.avatar = avatar;
     }
 }
 
 

Method Summary

Methods

Modifier and Type	Method and Description
ObjectMetadata	downloadTo(File destination) Convenient method to synchronously download to the specified file from the S3 object represented by this S3Link.
AmazonS3Client	getAmazonS3Client()
String	getBucketName()
String	getKey()
Region	getS3Region()
TransferManager	getTransferManager()
PutObjectResult	uploadFrom(File source) Convenient method to synchronously upload from the given file to the S3 object represented by this S3Link.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getKey

public String getKey()

getBucketName

public String getBucketName()

getS3Region

public Region getS3Region()

getAmazonS3Client

public AmazonS3Client getAmazonS3Client()

getTransferManager

public TransferManager getTransferManager()

uploadFrom

public PutObjectResult uploadFrom(File source)

Convenient method to synchronously upload from the given file to the S3 object represented by this S3Link.

Parameters:

source - source file to upload from

Returns:

A PutObjectResult object containing the information returned by Amazon S3 for the newly created object.

downloadTo

public ObjectMetadata downloadTo(File destination)

Convenient method to synchronously download to the specified file from the S3 object represented by this S3Link.

Parameters:

destination - destination file to download to

Returns:

All S3 object metadata for the specified object. Returns null if constraints were specified but not met.