Google Docs API - 模拟用户文件下载

Question

通过 Google Apps 帐户使用 Google Docs Java API，是否可以模拟用户并下载文件？

当我运行下面的程序时，它显然是登录到域并冒充用户，因为它检索其中一个文件的详细信息并打印出文件标题。但是，当它尝试下载文件时，会抛出 ServiceForbiddenException。

如果 Java API 无法实现，有谁知道我的程序是否可以编写 HTTP 请求以使用协议 API 下载文件？

public class AuthExample {

private static DocsService docService = new DocsService("Auth Example");

public static void main(String[] args)
    throws Exception
{
    String adminUser = args[0];
    String adminPassword = args[1];
    String authToken = args[2];
    String impersonatedUser = args[3];

    loginToDomain(adminUser, adminPassword, authToken);

    URL url = new URL( "https://docs.google.com/feeds/" + impersonatedUser + "/private/full" );
    DocumentListFeed feed = docService.getFeed(url, DocumentListFeed.class);

    DocumentListEntry entry = feed.getEntries().get(0);

    String title = entry.getTitle().getPlainText();
    System.out.println( title );

    String type = entry.getType();
    if ( type.equals("document") )
    {
        String encodedAdminUser = URLEncoder.encode(adminUser);
        String resourceId = entry.getResourceId();
        String resourceIdNoPrefix = resourceId.substring( resourceId.indexOf(':')+1 );

        String downloadUrl =
                "https://docs.google.com/feeds/download/documents/Export" +
                "?xoauth_requestor=" + encodedAdminUser +
                "&docId=" + resourceIdNoPrefix +
                "&exportFormat=doc";

        downloadFile( downloadUrl, title + ".doc" );
    }
}

private static void loginToDomain(String adminUser, String adminPassword, String authToken)
        throws OAuthException, AuthenticationException
{
    String domain = adminUser.substring( adminUser.indexOf('@')+1 );

    GoogleOAuthParameters oauthParameters = new GoogleOAuthParameters();
    oauthParameters.setOAuthConsumerKey(domain);
    oauthParameters.setOAuthConsumerSecret(authToken);
    oauthParameters.setOAuthType(OAuthType.TWO_LEGGED_OAUTH);
    oauthParameters.setScope("https://docs.google.com/feeds/ http://spreadsheets.google.com/feeds/ http://docs.googleusercontent.com/");

    docService.useSsl();
    docService.setOAuthCredentials(oauthParameters, new OAuthHmacSha1Signer());
    docService.setUserCredentials(adminUser, adminPassword);
}


// Method pasted directly from Google documentation
public static void downloadFile(String exportUrl, String filepath)
        throws IOException, MalformedURLException, ServiceException
{
    System.out.println("Exporting document from: " + exportUrl);

    MediaContent mc = new MediaContent();
    mc.setUri(exportUrl);
    MediaSource ms = docService.getMedia(mc);

    InputStream inStream = null;
    FileOutputStream outStream = null;

    try {
        inStream = ms.getInputStream();
        outStream = new FileOutputStream(filepath);

        int c;
        while ((c = inStream.read()) != -1) {
            outStream.write(c);
        }
    } finally {
        if (inStream != null) {
            inStream.close();
        }
        if (outStream != null) {
            outStream.flush();
            outStream.close();
        }
    }
}

}

Answer 1

如果您将 Oauth2 与 ServiceAccounts 一起使用，模拟将按预期工作