Download the files inside compressed .gz files from S3 Bucket

Question

I have a set of .gz compressed files in s3 bucket. I want to download the csv file inside the .gz file. I tried to extract the .gz file and put it into the s3Object. Now i need to extract the s3 object and download the csv file inside it using java. Please advise.This is the code I used.Now i am able to download gz file. But I need to download csv file inside gz.

S3Object object = s3Client.getObject(“bucket”,“Location/file.gz”);
final String encoding = null;
return ResponseEntity.ok(IOUtils.toString(object.getObjectContent(), encoding));

I need help in unzipping the gz file in s3object and return the decompressed contents in the response.

Answer 1

The below code will convert your gunzip file into plain data, but I'm not sure 100% about your actual issue, whether you want to display the content in browser itself or you want to send it as Save as Option , that's why I did a minimum code change to your code assuming you have only problem in converting gunzip format to CSV data, hope you could modify/enhance it that suits you best.

import java.util.zip.GZIPInputStream;
//your method begins from here
final AmazonS3 s3 = AmazonS3ClientBuilder.defaultClient();


S3Object object = s3.getObject("your-bucket", "file-path");


return ResponseEntity.ok(IOUtils.toString(new GZIPInputStream(object.getObjectContent())));