OAuth2 authorization from Java/Scala using google

问题:

How would you perform the same flow as the Google .Net sample at subsection "Performing OAuth 2.0", using an equivalent Java api?

That .Net sample I am trying to mimic using Java api seems fit for sending an api request to create an authorization url, then assumes I would use that url in a browser to obtain an access code... thus allowing server-side code to use google spreadsheets api thereafter, for that one google account.

The closet Google Java api class I spotted is OAuthHelper, but it seems to require the userAuthorizationUrl at instantiation time, which is actually what I wish to obtain from it via its own createUserAuthorizationUrl method after I will have managed to instantiate it - a bit of a cyclic conundrum to me. Which seems to indicate I am missing something in my assumptions, probably this is not the right class to use for mimicking the .Net code sample.

Your help much appreciated.

回答1:

Looks like http://soatutorials.blogspot.co.at/2013/08/google-spreadsheet-api-connecting-with.html has it for Java.

Scala solution code, courtesy of http://javatoscala.com/ :

package com.articlio.googleApi
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

import com.google.gdata.client.GoogleService;
import com.google.gdata.client.authn.oauth.GoogleOAuthHelper;
import com.google.gdata.client.authn.oauth.GoogleOAuthParameters;
import com.google.gdata.client.authn.oauth.OAuthException;
import com.google.gdata.client.authn.oauth.OAuthHmacSha1Signer;
import com.google.gdata.client.authn.oauth.OAuthRsaSha1Signer;
import com.google.gdata.client.authn.oauth.OAuthSigner;
import com.google.gdata.client.spreadsheet.SpreadsheetService;
import com.google.gdata.data.spreadsheet.SpreadsheetFeed
import com.google.gdata.data.BaseEntry;
import com.google.gdata.data.BaseFeed;
import com.google.gdata.data.Feed;
import com.google.gdata.util.AuthenticationException;
import com.google.gdata.util.ServiceException;

//remove if not needed
import scala.collection.JavaConversions._

object OAuth2Sample {

  def loginOAuth2(clientID: String, clientSecret: String) {
    val SCOPES = "https://docs.google.com/feeds https://spreadsheets.google.com/feeds"
    val oauthParameters = new GoogleOAuthParameters
    oauthParameters.setOAuthConsumerKey(clientID) //
    var signer: OAuthSigner = null
    oauthParameters.setOAuthConsumerSecret(clientSecret) //
    signer = new OAuthHmacSha1Signer()
    val oauthHelper = new GoogleOAuthHelper(signer)
    oauthParameters.setScope(SCOPES)
    try {
      oauthHelper.getUnauthorizedRequestToken(oauthParameters)
    } catch {
      case e: OAuthException => e.printStackTrace()
    }
    val requestUrl = oauthHelper.createUserAuthorizationUrl(oauthParameters)
    println(requestUrl)
    println("Please visit the URL above to authorize your OAuth " + 
      "request token.  Once that is complete, press any key to " + 
      "continue...")
    try {
      System.in.read()
    } catch {
      case e: IOException => e.printStackTrace()
    }
    var token: String = null
    try {
      token = oauthHelper.getAccessToken(oauthParameters)
    } catch {
      case e: OAuthException => e.printStackTrace()
    }
    println("OAuth Access Token: " + token)
    println()
    var feedUrl: URL = null
    try {
      feedUrl = new URL("https://spreadsheets.google.com/feeds/spreadsheets/private/full")
    } catch {
      case e: MalformedURLException => e.printStackTrace()
    }
    println("Sending request to " + feedUrl.toString)
    println()
    val googleService = new SpreadsheetService("oauth-sample-app")
    try {
      googleService.setOAuthCredentials(oauthParameters, signer)
    } catch {
      case e: OAuthException => e.printStackTrace()
    }
    val feed = googleService.getFeed(feedUrl, classOf[SpreadsheetFeed])
    val spreadsheets = feed.getEntries
    println("Response Data:")
    println("=====================================================")
    if (spreadsheets != null) {
      for (spreadsheet <- spreadsheets) {
        println(spreadsheet.getTitle.getPlainText)
      }
    }
    println("=====================================================")
    println()
    println("Revoking OAuth Token...")
    try {
      oauthHelper.revokeToken(oauthParameters)
    } catch {
      case e: OAuthException => e.printStackTrace()
    }
    println("OAuth Token revoked...")
  }
}

For scala however, you currently also need to apply this...