List Objects in a Bucket

List All Objects by Pagination

This SDK method will allow you to get all the objects present in a particular bucket by pagination. The Bucket reference used in the below code snippet is the component instance.

For each call, a limited number of objects will be returned, and the next call will be initiated only if a continuation token is returned.

Parameters Used

The response we get will contain the following properties of the bucket, which will be stored in moreOptions:

• key count: Will contain the value of the number of objects that are being returned
• max keys: The maximum limit of objects that can be returned
• Truncated: Will contain the status to notify if a bucket is truncated or not.
• contents: List of object details
• continuation_token: If you a sent a continuation_token in the request, it will be shown in the response.
• next_continuation_token: If the response was truncated, the value of this key must be passed as continuation_token to the same method for retrieving the next set of objects.

With each iteration, we will list the maxKey number of objects and check if nextToken has been created. Using nextToken we will continue the iteration till all the objects have been listed.

Ensure the following packages are imported:

    

        
copy
        

            

        
    
    

         import com.zc.component.stratus.ZCBucket;
import com.zc.component.stratus.ZCStratus;
import com.zc.component.stratus.beans.ZCListObjectOptions;
import com.zc.component.stratus.beans.ZCPagedObjectResponse;
import com.zc.component.stratus.ZCObject;

    

    

        
copy
        

            

        
    
    

         String nextToken = null;
String maxKey = "10";
String prefix = "Sam";

do {
    ZCListObjectOptions options = new ZCListObjectOptions();
    options.setMaxKey(maxKey); // Default: 1000
    options.setContinuationToken(nextToken); // Fetch next page
    options.setFolderListing("true"); // Default: false
    options.setOrderBy("desc"); // Default: "asc"
    options.setPrefix(prefix); // Optional

    ZCPagedObjectResponse res = bucket.listPagedObjects(options);

    System.out.println("Object count: " + res.getKeyCount());
    System.out.println("Max key: " + res.getMaxKey());
    System.out.println("Is truncated: " + res.getTruncated());

    for (ZCObject key : res.getContents()) {
        System.out.println("Object name: " + key.getKey());
        System.out.println("Content type: " + key.getContentType());
        System.out.println("Size: " + key.getSize());
        System.out.println("Metadata: " + key.getMetaData());
        System.out.println("Version ID: " + key.getVersionId());
        System.out.println("ETag: " + key.getEtag());
        System.out.println("Object type: " + key.getKeyType());
        System.out.println("Cached URL: " + key.getCachedUrl());
    }

    nextToken = res.getNextToken();
} while (nextToken != null);

    

List Objects Through Iteration

Using this SDK method, you can get all the objects present in a bucket in a single API call, using iteration technique. The Bucket reference used in the below code snippet is the component instance.

Ensure the following packages are imported:

    

        
copy
        

            

        
    
    

         import java.util.Iterator;
import com.zc.component.stratus.ZCObject;
import com.zc.component.stratus.beans.ZCListObjectOptions;
import java.util.List;

    

    

        
copy
        

            

        
    
    

         ZCListObjectOptions options = new ZCListObjectOptions();
options.setFolderListing("true"); // Default: false
options.setMaxKey("2");           // Default: 1000
options.setOrderBy("desc");       // Default: "asc"

// Get iterable object list
Iterable<List<ZCObject>> paginationIterable = bucket.listIterableObjects(options);
Iterator<List<ZCObject>> iterator = paginationIterable.iterator();

while (iterator.hasNext()) {
    List<lZCObject> objectList = iterator.next();
    for (ZCObject obj : objectList) {
        System.out.println(obj.getKey());
    }
}