I have written a AWS Lambda Function, Its objective is that on invocation - it read the contents of a file say x.db, get a specific value out of it and return to the caller.But this x.db file changes time to time. So I would like to upload this x.db file to S3 and read it from AWS Lambda function as like reading a file.
File xFile = new File("S3 file in x.db");
How to read such x.db S3 file from AWS Lambda Function written in Java ?
Use the Java S3 SDK. If you upload a file called x.db to an S3 bucket mybucket, it would look something like this:
import com.amazonaws.services.s3.*;
import com.amazonaws.services.s3.model.*;
...
AmazonS3 client = new AmazonS3Client();
S3Object xFile = client.getObject("mybucket", "x.db");
InputStream contents = xFile.getObjectContent();
In addition, you should ensure the role you've assigned to your lambda function has access to the S3 bucket. Apply a policy like this:
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::mybucket",
"arn:aws:s3:::mybucket/*"
]
}]
