How to convert Salesforce contentversion to actual file

Question

I have created a rest API that returns the list of opportunities as well as files attached to the opportunities. I am able to call the API and retrieve the data via POSTMAN. This is the code:

@RestResource(urlMapping='/api/getOpportunities')
global with sharing class GetOpportunities {
    @HttpGet
    global static List<sObject> doGet() {
        RestRequest req = RestContext.request;
        RestResponse res = RestContext.response;

        List<sObject> result=new List<sObject>();

        List<sObject> opps = [
            Select Id, Name, ........
            FROM Opportunity
            WHERE RecordType.Name = 'Test' AND
            StageName = 'XYZ' 
        ];

        Set<Id> contentDocIds = new Set<Id>();
        for (ContentDocumentLink cdl : [
            SELECT id, LinkedEntityId, ContentDocumentId 
            FROM ContentDocumentLink 
            WHERE LinkedEntityId IN (
                SELECT Id 
                FROM Opportunity 
                WHERE StageName = 'XYZ'
            )
        ]) {
            contentDocIds.add(cdl.ContentDocumentId); 
        }

        List<sObject> cvList = [
            select id, Checksum, ContentBodyId, 
                ContentDocumentId, ContentLocation, ContentModifiedById,
                ContentModifiedDate, ContentSize, ContentUrl, Description, 
                ExternalDataSourceId, ExternalDocumentInfo1,
                ExternalDocumentInfo2, FeaturedContentBoost, FeaturedContentDate, 
                FileExtension, FileType, FirstPublishLocationId, IsAssetEnabled, 
                IsLatest,IsMajorVersion, NegativeRatingCount,  Origin, OwnerId, PathOnClient, 
                PositiveRatingCount, PublishStatus, RatingCount, ReasonForChange, 
                SharingOption,SharingPrivacy, TagCsv, TextPreview, Title, VersionNumber, 
                VersionData 
            FROM ContentVersion 
            WHERE ContentDocumentId IN :contentDocIds
        ]; 

        result.addAll(opps);
        result.addAll(cvList);
        return result;
    }
}

Question:

The versiondata gives me some link right now e.g. /services/data/v47.0/sobjects/ContentVersion/0686C0000000i9OQAQ/VersionData

How do I convert it to actual content? I need the actual file e.g. pdf, ppt, jpg e.t.c.

Thanks

Answer 1

Your external caller needs to make an additional REST call to the URL given for the VersionData of each ContentVersion, i.e., <your Salesforce domain>/services/data/v47.0/sobjects/ContentVersion/0686C0000000i9OQAQ/VersionData.

Your caller would make one request per file to retrieve the data for each file individually.