Retrieving attachments from S3 Bucket

• Retrieving a file from doclinks is straightforward. We can pass the doclink URL to ‘File’ object as shown below.

                    file=File("docklink-filepath")

• However, if the attachments are using an S3 bucket, then we cannot directly fetch ‘File’ object from URL.

• Few additional steps are required to convert as file before sending or uploading to an API

Steps:

• Get the byte array of attachment from S3 bucket

• Create a temporary file in server or pod

• Create ‘File-output stream’ of the temporary file

• Write the byte array into the ‘File-output stream’.

• Upload the ‘File-output stream’ to REST API to send as file attachment.

• Delete the temporary file

Source Code:

https://github.com/sankargh/COSApi_Attachment/blob/main/Upload_S3Bucket_Document_REST_API.py

from com.ibm.tivoli.maximo.cos import COSApi

from java.io import File, FileOutputStream, FileInputStream

from java.net  import URL, HttpURLConnection;

from org.apache.http.entity.mime import MultipartEntityBuilder;

cosApi = COSApi(False)

bucketname = service.getProperty(mxe.cosbucketname)

urlString = filePath.split()

fileName = urlString[-1]

#Create Temporary File in Pod

FILEPATH = "root\maximo\temp\fileName.txt";

uploadFile =  File(FILEPATH);

uploadFile.createNewFile();

fos = FileOutputStream(uploadFile);

## Option - 1 

#Get byteArray from S3 Bucket

docBytes=cosApi.getFile(bucketname,fileName)

# Write the Bytes to File Outputstream

fos.write(docBytes);

print(Successfully+  byte inserted);

# Close the file connections

fos.close();

'''

## Option - 2

# Get Input Stream from s3 bucket

fis=cosApi.streamFile(bucketname,fileName)

byteRead=0

#Read byte by byte

while ((byteRead = fis.read()) != -1)

    #Write byte by byte

    fos.write(byteRead)

'''

#Upload File Outputstream to REST API

builder = MultipartEntityBuilder.create();

builder.addBinaryBody(file, uploadFile);

entity = builder.build();

url = URL("https:\\clientdomainhostname\restapi\fileupload");

conn = url.openConnection();

conn.setDoOutput(True);

conn.setRequestMethod(POST);

conn.addRequestProperty(Content-Length, str(entity.getContentLength()));

fos = conn.getOutputStream();

entity.writeTo(fos);

fos.close();

conn.connect();

conn.getInputStream().close();

statusCode = conn.getResponseCode();

#Delete the Temporary File After Upload

uploadFile.delete()