(Java) 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.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example assumes the Chilkat HTTP API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkHttp http = new CkHttp();

    // Insert your access key here:
    http.put_AwsAccessKey("AWS_ACCESS_KEY");

    // Insert your secret key here:
    http.put_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.)

    CkStringBuilder sbContinuationToken = new CkStringBuilder();
    boolean bGetMore = true;
    CkStringBuilder sbUri = new CkStringBuilder();
    CkXml xml = new CkXml();
    boolean success;
    String itemKey;
    String itemSizeDecimalStr;
    String lastModTimestamp;
    CkDateTime dt = new CkDateTime();

    while (bGetMore == true) {

        // 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.get_Length() > 0) {
            sbUri.Append("&continuation-token=");
            sbUri.Append(sbContinuationToken.getEncoded("url","utf-8"));
            }

        String strXml = http.s3_ListBucketObjects(sbUri.getAsString());
        if (http.get_LastMethodSuccess() != true) {
            System.out.println(http.lastErrorText());
            return;
            }

        System.out.println("Response status code = " + http.get_LastStatus());

        success = xml.LoadXml(strXml);
        if (success != true) {
            System.out.println(xml.lastErrorText());
            return;
            }

        // 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.get_LastStatus() != 200) {
            System.out.println(xml.getXml());
            System.out.println("Failed.");
            return;
            }

        // 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..
        int numItems = xml.NumChildrenHavingTag("Contents");
        System.out.println("Number of bucket items = " + numItems);

        int i = 0;
        while (i < numItems) {
            xml.put_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.
            boolean bLocal = true;
            CkDtObj dtObj = dt.GetDtObj(bLocal);

            System.out.println(i + ": " + itemKey + ", " + itemSizeDecimalStr + ", " + dtObj.get_Day() + "-" + dtObj.get_Month()
                 + "-" + dtObj.get_Year() + ":" + dtObj.get_Hour() + ":" + dtObj.get_Minute());

            i = i+1;
            }

        // Check IsTruncated.
        bGetMore = false;
        if (xml.ChildContentMatches("IsTruncated","true",true) == true) {
            sbContinuationToken.SetString(xml.getChildContent("NextContinuationToken"));
            if (sbContinuationToken.get_Length() > 0) {
                bGetMore = true;
                }

            }

        }

    // 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
    // 
    // 
  }
}