Hi, 

I was trying to upload a file to Amazon S3 bucket using the following source code.

public class AmazonFileUpload
{
    public static String uploadFile(Blob body, String name, String contentType, String appUName)
    {
        String uploaded_url;
        try
        {
            if(body != null && String.isNotBlank(name) && String.isNotBlank(contentType))
            {
                String attachmentBody = EncodingUtil.base64Encode(body);
                String formattedDateString = Datetime.now().formatGMT('EEE, dd MMM yyyy HH:mm:ss z');
                String key,secret,bucketname,host,filename,folderName;
                String method = 'PUT';
				key = Amazon_Key__c; //From Custom Settings
                secret =Amazon_Secret__c; //From Custom Settings
                bucketname = Amazon_Bucket_Name__c; //From Custom Settings
                host = Amazon_Host__c; //From Custom Settings
                filename = name; 
                folderName = appUName;
				folderName= folderName.replaceAll( '\\s+', '');
                HttpRequest req = new HttpRequest();
                req.setMethod(method);
                req.setEndpoint('http://' + bucketname + '.' + host + '/' + folderName + '/' + filename);
                req.setHeader('Host', bucketname + '.' + host);
                req.setHeader('Content-Length', String.valueOf(attachmentBody.length()));
                req.setHeader('Content-Encoding', 'UTF-8');
                req.setHeader('Content-type', contentType);
                req.setHeader('Connection', 'keep-alive');
                req.setHeader('Date', formattedDateString);
                req.setHeader('ACL', 'public-read');
                
                Blob blobBody = EncodingUtil.base64Decode(attachmentBody);
                req.setBodyAsBlob(blobBody);
                filename = filename.replaceAll(' ', '');
                String stringToSign = 'PUT\n\n' + contentType + '\n' + formattedDateString + '\n' +  '/' + bucketname +  '/' +folderName + '/' + filename;
                String encodedStringToSign = EncodingUtil.urlEncode(stringToSign, 'UTF-8');
                system.debug('stringToSign='+stringToSign);
                
                Blob mac = Crypto.generateMac('HMACSHA1', blob.valueof(stringToSign),blob.valueof(secret));
                String signed = EncodingUtil.base64Encode(mac);
                String authHeader = 'AWS' + ' ' + key + ':' + signed;
                req.setHeader('Authorization',authHeader);
                String decoded = EncodingUtil.urlDecode(encodedStringToSign, 'UTF-8');
                
               
                Http http = new Http();
                HTTPResponse res = new HTTPResponse();               
                res = http.send(req);               
                String response = res.getBody();
                string url = req.getEndpoint();                
                if(res.getStatus() == 'OK' && res.getStatusCode() == 200)
                {
					 uploaded_url = 'https://'+Label.SIS_Amazon_Host+'/'+Label.SIS_Amazon_Bucket_Name+'/'+folderName+'/'+filename;
                }
                else
                {
                    return res.toString();
                }
            }
            else
            {
                return 'Something wrong happenned while uploading the file, please contact your system administrator.';
            }
        }
        catch(Exception e)
        {
            return 'ERROR: Uploading file to Amazon - '+e.getMessage()+' - '+e.getLineNumber();
        }
		
		return uploaded_url;
    }
}

The above source code is working fine for uploading the document.

But, I want to add one more method to this class, where I can delete an object from S3.