Folder

To create a folder, we need to have a bucket. We cannot create a folder at the root level. Folders can be nested. To create a folder under the bucket, we need to create an object with its content length metadata as 0 and an empty content so that it can be recognized as a folder:

ObjectMetadata metadata = new ObjectMetadata();
metadata.setContentLength(0);

InputStream emptyContent = new ByteArrayInputStream(new byte[0]);

PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, folderName + "/", emptyContent, metadata);

s3.putObject(putObjectRequest);

In the preceding code, you can see that the content length is set to 0, and an empty byte array input has been added. Apart from this, we provided the suffix "/" to the folder name so that we will be able to distinguish between the folder and the object inside the folder.

The following is the complete code to create a folder in a bucket:

package com.chapter3;

import java.io.ByteArrayInputStream;
import...