Pascal (Lazarus/Delphi)
Pascal (Lazarus/Delphi)
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 Pascal (Lazarus/Delphi) Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.Http,
Chilkat.StringBuilder,
Chilkat.DtObj,
Chilkat.Xml,
Chilkat.CkDateTime;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
http: THttp;
sbContinuationToken: TStringBuilder;
bGetMore: Boolean;
sbUri: TStringBuilder;
xml: TXml;
itemKey: string;
itemSizeDecimalStr: string;
lastModTimestamp: string;
dt: TCkDateTime;
dtObj: TDtObj;
strXml: string;
numItems: Integer;
i: Integer;
bLocal: Boolean;
begin
success := False;
// This example assumes the Chilkat HTTP API to have been previously unlocked.
// See Global Unlock Sample for sample code.
http := THttp.Create;
// 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 := TStringBuilder.Create;
bGetMore := True;
sbUri := TStringBuilder.Create;
xml := TXml.Create;
dt := TCkDateTime.Create;
dtObj := TDtObj.Create;
while bGetMore = True 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 = False) then
begin
WriteLn(http.LastErrorText);
Exit;
end;
WriteLn('Response status code = ' + http.LastStatus);
success := xml.LoadXml(strXml);
if (success = False) then
begin
WriteLn(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
WriteLn(xml.GetXml());
WriteLn('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');
WriteLn('Number of bucket items = ' + 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 := True;
dt.ToDtObj(bLocal,dtObj);
WriteLn(i + ': ' + itemKey + ', ' + itemSizeDecimalStr + ', ' + dtObj.Day + '-' + dtObj.Month + '-' + dtObj.Year + ':' + dtObj.Hour + ':' + dtObj.Minute);
i := i + 1;
end;
// Check IsTruncated.
bGetMore := False;
if (xml.ChildContentMatches('IsTruncated','true',True) = True) then
begin
sbContinuationToken.SetString(xml.GetChildContent('NextContinuationToken'));
if (sbContinuationToken.Length > 0) then
begin
bGetMore := True;
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
//
//
http.Free;
sbContinuationToken.Free;
sbUri.Free;
xml.Free;
dt.Free;
dtObj.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.