(Java) Get GMail Message Metadata

Demonstrates how to get the metadata for each message in a list of message IDs.

For more information, see https://developers.google.com/gmail/api/v1/reference/users/messages/get

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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.

    CkHttp http = new CkHttp();

    http.put_AuthToken("ACCESS_TOKEN");

    http.put_Accept("application/json");

    // Let's say we have the following JSON containing a list of message ID's

    // {
    //   "messages": [
    //     {
    //       "id": "1712bc1dc22da2a2",
    //       "threadId": "1712bc1dc22da2a2"
    //     },
    //     {
    //       "id": "1712b94fa2168040",
    //       "threadId": "1712b94fa2168040"
    //     },
    //     {
    //       "id": "1711e4bd96ded05e",
    //       "threadId": "1711e4bd96ded05e"
    //     },
    //     {
    //       "id": "1711de0d119e751e",
    //       "threadId": "1711de0d119e751e"
    //     },
    //     {
    //       "id": "1711c81a43050f59",
    //       "threadId": "1711c81a43050f59"
    //     },
    //     {
    //       "id": "1711c2c1516abce5",
    //       "threadId": "1711c2c1516abce5"
    //     },
    //     {
    //       "id": "1711c161e655c915",
    //       "threadId": "1711c161e655c915"
    //     },
    //     {
    //       "id": "171199c6e454558c",
    //       "threadId": "171199c6e454558c"
    //     },
    //     {
    //       "id": "17119474c8aa248e",
    //       "threadId": "17119474c8aa248e"
    //     }
    //   ],
    //   "nextPageToken": "16710921492249671162",
    //   "resultSizeEstimate": 309
    // }

    // Normally your program would have the above JSON in a string variable (obtained from a previous call to get
    // a list of message IDs from a GMail mailbox).  In this example, we'll load the JSON from a file.
    CkJsonObject jsonMsgIds = new CkJsonObject();
    boolean success = jsonMsgIds.LoadFile("qa_data/json/gmail_message_ids.json");

    String id;
    int i = 0;
    int count_i = jsonMsgIds.SizeOfArray("messages");
    while (i < count_i) {
        jsonMsgIds.put_I(i);
        id = jsonMsgIds.stringOf("messages[i].id");

        // Get the metadata for this message ID.
        http.SetUrlVar("id",id);

        CkHttpResponse resp = http.QuickRequest("GET","https://www.googleapis.com/gmail/v1/users/userId/messages/{$id}?format=metadata");
        if (http.get_LastMethodSuccess() != true) {
            System.out.println(http.lastErrorText());
            return;
            }

        System.out.println("Response Status Code: " + resp.get_StatusCode());

        CkJsonObject jsonResponse = new CkJsonObject();
        jsonResponse.Load(resp.bodyStr());
        jsonResponse.put_EmitCompact(false);
        System.out.println(jsonResponse.emit());

        if (resp.get_StatusCode() != 200) {
            System.out.println("Failed.");

            return;
            }

        i = i+1;
        }

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