(Delphi ActiveX) Amazon S3 List More than 1000 Objects in Bucket

See more Amazon S3 Examples

S3 limits the size of the "List Objects" response to 1000 objects. To retrieve a listing of all of the objects in a bucket containing more than 1000 objects, we'll need to send several requests using continuation tokens.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: TChilkatHttp;
sbContinuationToken: TChilkatStringBuilder;
bGetMore: Integer;
sbUri: TChilkatStringBuilder;
xml: TChilkatXml;
success: Integer;
itemKey: WideString;
itemSizeDecimalStr: WideString;
lastModTimestamp: WideString;
dt: TCkDateTime;
strXml: WideString;
numItems: Integer;
i: Integer;
bLocal: Integer;
dtObj: IDtObj;

begin
// This example assumes the Chilkat HTTP API to have been previously unlocked.
// See Global Unlock Sample for sample code.

http := TChilkatHttp.Create(Self);

// Insert your access key here:
http.AwsAccessKey := 'AWS_ACCESS_KEY';

// Insert your secret key here:
http.AwsSecretKey := 'AWS_SECRET_KEY';

// For the example, we'll get a listing containing approx. 25 objects
// using continuation tokens with an artificially low max-keys set to 5.
// (You may omit the max-keys query parameter to get the default 1000 maximum
// number of keys per request.)

sbContinuationToken := TChilkatStringBuilder.Create(Self);
bGetMore := 1;
sbUri := TChilkatStringBuilder.Create(Self);
xml := TChilkatXml.Create(Self);

dt := TCkDateTime.Create(Self);

while bGetMore = 1 do
  begin

    // Make sure to set the "list-type" query param equal to "2".
    // This chooses the GET Bucket (List Objects) Version 2 of the method.

    // IMPORTANT: You must include the max-keys param to get a response with a continuation token.
    // S3 limits the number of objects in a single response to 1000. Therefore, your max-keys
    // can be up to 1000.  If, for example, you have 2000 objects and do not specify
    // max-keys, then the response will contain 1000 objects with no continuation token. 
    sbUri.SetString('chilkat100?list-type=2&max-keys=5');
    if (sbContinuationToken.Length > 0) then
      begin
        sbUri.Append('&continuation-token=');
        sbUri.Append(sbContinuationToken.GetEncoded('url','utf-8'));
      end;
    strXml := http.S3_ListBucketObjects(sbUri.GetAsString());
    if (http.LastMethodSuccess <> 1) then
      begin
        Memo1.Lines.Add(http.LastErrorText);
        Exit;
      end;

    Memo1.Lines.Add('Response status code = ' + IntToStr(http.LastStatus));

    success := xml.LoadXml(strXml);
    if (success <> 1) then
      begin
        Memo1.Lines.Add(xml.LastErrorText);
        Exit;
      end;
    // If the response status code was not 200, then the XML response is not a 
    // listing of objects, but instead contains error information.
    if (http.LastStatus <> 200) then
      begin
        Memo1.Lines.Add(xml.GetXml());
        Memo1.Lines.Add('Failed.');
        Exit;
      end;

    // If this is not the final response, then we'll get an XML response that begins
    // like this.  (The IsTruncated child will be "true", and the NextContinuationToken
    // will have a value to be used in the next request.)
    // 	<?xml version="1.0" encoding="UTF-8" ?>
    // 	<ListBucketResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    // 	    <Name>chilkat100</Name>
    // 	    <Prefix />
    // 	    <NextContinuationToken>1Mlcx+W9OKsr8cxp3DP6r71wgsTUMj0vqlntWoaJKNbYdrauLdf40LsUdBeSYGFhzbGIHdcf5DSLcEBWbqG+1fW1UcQkUW1V4qgQONAKOwb8y8vOLJAQ8iQ==</NextContinuationToken>
    // 	    <KeyCount>5</KeyCount>
    // 	    <MaxKeys>5</MaxKeys>
    // 	    <IsTruncated>true</IsTruncated>
    // 	

    // Iterate over the bucket items in this chunk get information for each..
    numItems := xml.NumChildrenHavingTag('Contents');
    Memo1.Lines.Add('Number of bucket items = ' + IntToStr(numItems));

    i := 0;
    while i < numItems do
      begin
        xml.I := i;

        itemKey := xml.GetChildContent('Contents[i]|Key');
        itemSizeDecimalStr := xml.GetChildContent('Contents[i]|Size');
        lastModTimestamp := xml.GetChildContent('Contents[i]|LastModified');

        dt.SetFromRfc822(lastModTimestamp);
        // Get a local date/time.
        bLocal := 1;
        dtObj := dt.GetDtObj(bLocal);

        Memo1.Lines.Add(IntToStr(i) + ': ' + itemKey + ', ' + itemSizeDecimalStr + ', ' + IntToStr(dtObj.Day) + '-' + IntToStr(dtObj.Month)
             + '-' + IntToStr(dtObj.Year) + ':' + IntToStr(dtObj.Hour) + ':' + IntToStr(dtObj.Minute));

        i := i + 1;
      end;

    // Check IsTruncated.
    bGetMore := 0;
    if (xml.ChildContentMatches('IsTruncated','true',1) = 1) then
      begin
        sbContinuationToken.SetString(xml.GetChildContent('NextContinuationToken'));
        if (sbContinuationToken.Length > 0) then
          begin
            bGetMore := 1;
          end;
      end;

  end;

// The output of this example (when tested) was:

// Response status code = 200
// Number of bucket items = 5
// 0: Abc.ics, 1833, 25-5-2011:9:53
// 1: Corpse Bride film poster.jpg, 53481, 6-9-2016:13:32
// 2: chiliPepper.gif, 7718, 12-3-2017:12:18
// 3: chilkatdude.jpg, 35137, 20-5-2011:16:14
// 4: cloud.search/dfe/indexer/pscc/2016/3/28/id,x-2-15-0-25-87-0.json, 1238, 2-4-2016:12:0
// Response status code = 200
// Number of bucket items = 5
// 0: cloud.search/dfe/indexer/pscc/2016/3/28/idx-2-15-0-25-87-0.json, 1238, 2-4-2016:11:33
// 1: dude.gif, 6373, 25-5-2011:17:29
// 2: french.txt, 47, 12-3-2017:12:18
// 3: hamlet.xml, 279658, 2-5-2016:12:21
// 4: hamlet_play.xml, 279658, 20-3-2017:8:22
// Response status code = 200
// Number of bucket items = 5
// 0: images/sea_creatures/starfish123.jpg, 6229, 19-1-2017:10:45
// 1: images/sea_creatures/starfishåäö.jpg, 6229, 19-1-2017:12:7
// 2: new folder/, 0, 26-11-2014:12:36
// 3: new_starfish.jpg, 6229, 20-3-2017:8:22
// 4: pigs.xml, 2804, 20-3-2017:8:22
// Response status code = 200
// Number of bucket items = 5
// 0: somethingBig.zip, 13089458, 26-9-2016:9:29
// 1: starfish.jpg, 6229, 12-3-2017:12:18
// 2: starfish/, 0, 10-11-2014:10:7
// 3: starfish/starfish.jpg, 6229, 10-11-2014:10:8
// 4: starfish/starfish2.jpg, 6229, 19-11-2014:10:36
// Response status code = 200
// Number of bucket items = 5
// 0: starfish/starfish3.jpg, 6229, 24-11-2014:14:33
// 1: starfish2.jpg, 5987, 20-4-2012:12:6
// 2: starfish3.jpg, 5987, 11-4-2012:7:10
// 3: starfishA.jpg, 6229, 10-5-2016:8:44
// 4: starfishCust.jpg, 6229, 12-11-2014:18:25
// Response status code = 200
// Number of bucket items = 1
// 0: xyz.ics, 1833, 25-5-2011:8:52
// 
// 
end;