Chilkat Examples

ChilkatHOME.NET Core C#Android™AutoItCC#C++Chilkat2-PythonCkPythonClassic ASPDataFlexDelphi ActiveXDelphi DLLGoJavaLianjaMono C#Node.jsObjective-CPHP ActiveXPHP ExtensionPerlPowerBuilderPowerShellPureBasicRubySQL ServerSwift 2Swift 3,4,5...TclUnicode CUnicode C++VB.NETVBScriptVisual Basic 6.0Visual FoxProXojo Plugin

Java Examples

Web API Categories

ASN.1
AWS KMS
AWS Misc
Amazon EC2
Amazon Glacier
Amazon S3
Amazon S3 (new)
Amazon SES
Amazon SNS
Amazon SQS
Async
Azure Cloud Storage
Azure Key Vault
Azure Service Bus
Azure Table Service
Base64
Bounced Email
Box
CAdES
CSR
CSV
Certificates
Code Signing
Compression
DKIM / DomainKey
DNS
DSA
Diffie-Hellman
Digital Signatures
Dropbox
Dynamics CRM
EBICS
ECC
Ed25519
Email Object
Encryption
FTP
FileAccess
Firebase
GMail REST API
GMail SMTP/IMAP/POP
Geolocation
Google APIs
Google Calendar
Google Cloud SQL
Google Cloud Storage
Google Drive
Google Photos
Google Sheets
Google Tasks
Gzip
HTML-to-XML/Text
HTTP

HTTP Misc
IMAP
JSON
JSON Web Encryption (JWE)
JSON Web Signatures (JWS)
JSON Web Token (JWT)
Java KeyStore (JKS)
MHT / HTML Email
MIME
MS Storage Providers
Microsoft Graph
Misc
NTLM
OAuth1
OAuth2
OIDC
Office365
OneDrive
OpenSSL
Outlook
Outlook Calendar
Outlook Contact
PDF Signatures
PEM
PFX/P12
PKCS11
POP3
PRNG
REST
REST Misc
RSA
SCP
SCard
SFTP
SMTP
SSH
SSH Key
SSH Tunnel
ScMinidriver
SharePoint
SharePoint Online
Signing in the Cloud
Socket/SSL/TLS
Spider
Stream
Tar Archive
ULID/UUID
Upload
WebSocket
XAdES
XML
XML Digital Signatures
XMP
Zip
curl

 

 

 

(Java) Download Binary File to In-Memory Bytes

This example demonstrates how to download the binary content of a file from Google Drive directly into local memory.

Chilkat Java Downloads

Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris

Java Libs for Android

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[])
  {
    boolean success = true;

    // It 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 
    // Google Drive scope.

    CkAuthGoogle gAuth = new CkAuthGoogle();
    gAuth.put_AccessToken("GOOGLE-DRIVE-ACCESS-TOKEN");

    CkRest rest = new CkRest();

    // Connect using TLS.
    // A single REST object, once connected, can be used for many Google Drive REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    boolean bAutoReconnect = true;
    success = rest.Connect("www.googleapis.com",443,true,bAutoReconnect);

    // Provide the authentication credentials (i.e. the access token)
    rest.SetAuthGoogle(gAuth);

    // ------------------------------------------------------------------------------
    // To download a file, we must know the file ID.
    // In a previous example (see Build Local Metadata Cache
    // we built a local cache to make it easy to lookup file IDs given a file path.
    // Let's say we want to download "testFolder/abc/123/penguins.jpg".
    // First we lookup the fileId in the cache.  With the fileId, we can download the file.
    CkCache gdCache = new CkCache();
    gdCache.put_Level(0);
    gdCache.AddRoot("C:/ckCache/googleDrive");

    String fileId = gdCache.fetchText("testFolder/abc/123/penguins.jpg");
    if (gdCache.get_LastMethodSuccess() != true) {
        System.out.println("Filepath not found in cache.");
        return;
        }

    // We need to send a GET request like this:
    // GET https://www.googleapis.com/drive/v3/files/fileId?alt=media
    // The fileId is part of the path.
    CkStringBuilder sbPath = new CkStringBuilder();
    sbPath.Append("/drive/v3/files/");
    sbPath.Append(fileId);
    rest.AddQueryParam("alt","media");

    // To download to memory, we'll send the request in one call, then receive
    // the response header, and then the response body.
    // If the response header indicates failure or an unexpected response, then the
    // body is not the data we desire.

    // First send the HTTP request.
    success = rest.SendReqNoBody("GET",sbPath.getAsString());
    if (success != true) {
        System.out.println(rest.lastErrorText());
        return;
        }

    // Get the response header.
    int statusCode = rest.ReadResponseHeader();
    if (statusCode != 200) {
        System.out.println("response status code = " + rest.get_ResponseStatusCode());
        System.out.println("response status text = " + rest.responseStatusText());
        System.out.println("response header: " + rest.responseHeader());

        // Read the response body (which should be error text or HTML)
        String errResponseBody = rest.readRespBodyString();
        if (rest.get_LastMethodSuccess() == true) {
            System.out.println("response body: " + errResponseBody);
            }

        return;
        }

    // Read the response body, which should contain the file data.
    CkByteData jpgBytes = new CkByteData();
    success = rest.ReadRespBodyBinary(jpgBytes);
    if (rest.get_LastMethodSuccess() != true) {
        System.out.println(rest.lastErrorText());
        return;
        }

    // Save jpgBytes to a file so we can examine the file to verify that it worked.
    CkFileAccess fac = new CkFileAccess();
    fac.WriteEntireFile("qa_output/penguins_out.jpg",jpgBytes);

    System.out.println("File downloaded.");
  }
}

 

© 2000-2024 Chilkat Software, Inc. All Rights Reserved.