Java

Download File from Dropbox (Streaming)

See more Dropbox Examples

Downloads a file from Dropbox, streaming it directly to a file in the filesystem. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.DateTime;
import com.chilkatsoft.chilkat2.DtObj;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Rest;
import com.chilkatsoft.chilkat2.Stream;

public class ChilkatExample {

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

        // A Dropbox access token should have been previously obtained.
        // Dropbox access tokens do not expire.
        // See Dropbox Access Token.

        Rest rest = new Rest();

        // Connect to Dropbox
        try {
            rest.connect("content.dropboxapi.com", 443, true, true);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Add request headers.
        rest.addHeader("Authorization", "Bearer DROPBOX_ACCESS_TOKEN");

        // The download "parameters" are contained in JSON passed in an HTTP request header.
        // This is the JSON indicating the file to be downloaded:
        // {
        //    "path": "/Homework/lit/hamlet.xml",
        // }

        JsonObject json = new JsonObject();
        json.appendString("path", "/Homework/lit/hamlet.xml");
        rest.addHeader("Dropbox-API-Arg", json.emit());

        // Setup a file stream for the download
        Stream fileStream = new Stream();
        fileStream.setSinkFile("qa_output/hamletFromDropbox.xml");

        // Indicate that the call to FullRequestNoBody should send the response body
        // to fileStream if the response status code is 200.
        // If a non-success response status code is received, then nothing
        // is streamed to the output file and the error response is returned by FullRequestNoBody.
        int expectedStatus = 200;
        rest.setResponseBodyStream(expectedStatus, true, fileStream);

        String responseStr;
        try {
            responseStr = rest.fullRequestNoBody("POST", "/2/files/download");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // When successful, Dropbox responds with a 200 response code.
        if (rest.getResponseStatusCode() != 200) {
            // Examine the request/response to see what happened.
            System.out.println("response status code = " + rest.getResponseStatusCode());
            System.out.println("response status text = " + rest.getResponseStatusText());
            System.out.println("response header: " + rest.getResponseHeader());
            System.out.println("response body (if any): " + responseStr);
            System.out.println("---");
            System.out.println("LastRequestStartLine: " + rest.getLastRequestStartLine());
            System.out.println("LastRequestHeader: " + rest.getLastRequestHeader());
            return;
        }

        // Information about the downloaded file is also available as JSON in a response header.
        // The "dropbox-api-result" response header contains the information.  For example:
        String apiResult = rest.responseHdrByName("dropbox-api-result");
        System.out.println(apiResult);

        // In this case, the pretty-formatted dropbox-api-result JSON looks like this:
        // {
        //   "name": "hamlet.xml",
        //   "path_lower": "/homework/lit/hamlet.xml",
        //   "path_display": "/Homework/lit/hamlet.xml",
        //   "id": "id:74FkdeNuyKAAAAAAAAAAAQ",
        //   "client_modified": "2016-06-02T23:19:00Z",
        //   "server_modified": "2016-06-02T23:19:00Z",
        //   "rev": "9482db15f",
        //   "size": 279658
        // }

        // Load the JSON, pretty-print it, and demonstrate how to get some values...
        JsonObject jsonResult = new JsonObject();
        jsonResult.setEmitCompact(false);
        jsonResult.load(apiResult);
        // Show the JSON pretty-printed...
        System.out.println(jsonResult.emit());

        // Sample code to get data from the JSON response:
        int size = jsonResult.intOf("size");
        System.out.println("size = " + size);

        String rev = jsonResult.stringOf("rev");
        System.out.println("rev = " + rev);

        String clientModified = jsonResult.stringOf("client_modified");
        DateTime ckdt = new DateTime();
        ckdt.setFromTimestamp(clientModified);
        boolean bLocalTime = true;
        DtObj dt = new DtObj();
        ckdt.toDtObj(bLocalTime, dt);

        System.out.println(dt.getDay() + "/" + dt.getMonth() + "/" + dt.getYear() + " " + dt.getHour() + ":" + dt.getMinute());
    }
}