(Java) Google Cloud Storage List Bucket Objects

See more Google Cloud Storage Examples

List the objects in a Google Cloud Storage bucket.

For more information, see https://cloud.google.com/storage/docs/json_api/v1/objects/list

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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 requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // This example uses a previously obtained access token having permission for the 
    // scope "https://www.googleapis.com/auth/cloud-platform"

    // In this example, Get Google Cloud Storage OAuth2 Access Token, 
    // the service account access token was saved to a text file.  This example fetches the access token from the file..
    CkStringBuilder sbToken = new CkStringBuilder();
    sbToken.LoadFile("qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8");

    CkHttp http = new CkHttp();
    http.put_AuthToken(sbToken.getAsString());

    // For more info see Cloud Storage Documentation - Objects: list 
    // 
    boolean success = http.SetUrlVar("bucket","chilkat-ocean");
    success = http.SetUrlVar("PROJECT_NAME","ChilkatCloud");

    CkHttpResponse resp = http.QuickGetObj("https://www.googleapis.com/storage/v1/b/{$bucket}/o?project={$ChilkatCloud}");
    if (http.get_LastMethodSuccess() == false) {
        System.out.println(http.lastErrorText());
        return;
        }

    int responseCode = resp.get_StatusCode();
    if (responseCode == 401) {
        System.out.println(resp.bodyStr());
        System.out.println("If invalid credentials, then it is likely the access token expired.");
        System.out.println("Your app should automatically fetch a new access token and re-try.");

        return;
        }

    System.out.println("Response code: " + responseCode);
    System.out.println("Response body");

    CkJsonObject json = new CkJsonObject();
    success = json.Load(resp.bodyStr());

    json.put_EmitCompact(false);

    System.out.println(json.emit());

    // A response code = 200 indicates success, and the response body contains JSON such as this:

    // {
    //   "kind": "storage#objects",
    //   "items": [
    //     {
    //       "kind": "storage#object",
    //       "id": "chilkat-ocean/file with space char.jpg/1555776690752366",
    //       "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/file%20with%20space%20char.jpg",
    //       "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/file%20with%20space%20char.jpg?generation=1555776690752366&alt=media",
    //       "name": "file with space char.jpg",
    //       "bucket": "chilkat-ocean",
    //       "generation": "1555776690752366",
    //       "metageneration": "1",
    //       "contentType": "image/jpeg",
    //       "storageClass": "MULTI_REGIONAL",
    //       "size": "6229",
    //       "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
    //       "crc32c": "9RjgwQ==",
    //       "etag": "CO6WguiH3+ECEAE=",
    //       "timeCreated": "2019-04-20T16:11:30.752Z",
    //       "updated": "2019-04-20T16:11:30.752Z",
    //       "timeStorageClassUpdated": "2019-04-20T16:11:30.752Z"
    //     },
    //     {
    //       "kind": "storage#object",
    // 
    //       "id": "chilkat-ocean/penguins.jpg/1555775749593296",
    //       "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/penguins.jpg",
    //       "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/penguins.jpg?generation=1555775749593296&alt=media",
    //       "name": "penguins.jpg",
    //       "bucket": "chilkat-ocean",
    //       "generation": "1555775749593296",
    //       "metageneration": "1",
    //       "contentType": "image/jpeg",
    //       "storageClass": "MULTI_REGIONAL",
    //       "size": "777835",
    //       "md5Hash": "nTd7EM53jEk4s8fixjoimg==",
    //       "crc32c": "ixxYVw==",
    //       "etag": "CNCxnqeE3+ECEAE=",
    //       "timeCreated": "2019-04-20T15:55:49.593Z",
    //       "updated": "2019-04-20T15:55:49.593Z",
    //       "timeStorageClassUpdated": "2019-04-20T15:55:49.593Z"
    //     },
    //     {
    //       "kind": "storage#object",
    //       "id": "chilkat-ocean/starfish.jpg/1628958192639968",
    //       "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-ocean/o/starfish.jpg",
    //       "mediaLink": "https://www.googleapis.com/download/storage/v1/b/chilkat-ocean/o/starfish.jpg?generation=1628958192639968&alt=media",
    //       "name": "starfish.jpg",
    //       "bucket": "chilkat-ocean",
    //       "generation": "1628958192639968",
    //       "metageneration": "1",
    //       "contentType": "image/jpeg",
    //       "storageClass": "MULTI_REGIONAL",
    //       "size": "6229",
    //       "md5Hash": "LpxZ2/JmI2fcl9/dqF2gSA==",
    //       "crc32c": "9RjgwQ==",
    //       "etag": "COC/tJP2sPICEAE=",
    //       "timeCreated": "2021-08-14T16:23:12.660Z",
    //       "updated": "2021-08-14T16:23:12.660Z",
    //       "timeStorageClassUpdated": "2021-08-14T16:23:12.660Z"
    //     }
    //   ]
    // }

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON

    String id;
    String selfLink;
    String mediaLink;
    String name;
    String bucket;
    String generation;
    String metageneration;
    String contentType;
    String storageClass;
    String size;
    String md5Hash;
    String crc32c;
    String etag;
    String timeCreated;
    String updated;
    String timeStorageClassUpdated;

    String kind = json.stringOf("kind");
    int i = 0;
    int count_i = json.SizeOfArray("items");
    while (i < count_i) {
        json.put_I(i);
        kind = json.stringOf("items[i].kind");
        id = json.stringOf("items[i].id");
        selfLink = json.stringOf("items[i].selfLink");
        mediaLink = json.stringOf("items[i].mediaLink");
        name = json.stringOf("items[i].name");
        bucket = json.stringOf("items[i].bucket");
        generation = json.stringOf("items[i].generation");
        metageneration = json.stringOf("items[i].metageneration");
        contentType = json.stringOf("items[i].contentType");
        storageClass = json.stringOf("items[i].storageClass");
        size = json.stringOf("items[i].size");
        md5Hash = json.stringOf("items[i].md5Hash");
        crc32c = json.stringOf("items[i].crc32c");
        etag = json.stringOf("items[i].etag");
        timeCreated = json.stringOf("items[i].timeCreated");
        updated = json.stringOf("items[i].updated");
        timeStorageClassUpdated = json.stringOf("items[i].timeStorageClassUpdated");
        i = i+1;
        }
  }
}