java-google-oauth2-redisdatastore

Maintainers: feitnomore

This is a simple hack to be able to store Google Oauth2 Credential information on Redis using Java. This was developed to provide failover and scalability for an application running on top of containers. The library used is Redisson.

WARNING: Use it at your own risk.

INTRODUCTION

This was used in a plain Servlet application, with no fancy libs.

• Environment Variables

    export APP_NAME="my-app-name"
    export OAUTH_CLIENT_ID="my-oauth-client-id"
    export OAUTH_CLIENT_SECRET="my-oauth-client-secret"
    export OAUTH_SCOPES_FILE="scopes.txt"
    export REDIS_HOST="XXX.XXX.XXX.XXX"
    export REDIS_PORT="6379"
    export REDIS_NAME="oauth2"

• scopes.txt

https://www.googleapis.com/auth/drive
https://www.googleapis.com/auth/documents

• DoLogin.java

import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import com.google.api.client.auth.oauth2.AuthorizationCodeFlow;
import com.google.api.client.extensions.servlet.auth.oauth2.AbstractAuthorizationCodeServlet;
import com.google.api.client.http.GenericUrl;
import com.github.feitnomore.googleoauth2.redisdatastore.controllers.Oauth2Controller;

public class DoLogin extends AbstractAuthorizationCodeServlet {

    @Override
    protected String getUserId(HttpServletRequest request) {
      return request.getSession().getId();
    }
    
    @Override
    protected AuthorizationCodeFlow initializeFlow() throws IOException {
      return Oauth2Controller.newFlow();
    }
  
    @Override
    protected String getRedirectUri(HttpServletRequest request) {
      GenericUrl url = new GenericUrl(request.getRequestURL().toString());
      url.setRawPath("/doLoginCallback");
      return url.build();
    }
}

• DoLoginCallback.java

import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.api.client.auth.oauth2.AuthorizationCodeFlow;
import com.google.api.client.auth.oauth2.AuthorizationCodeResponseUrl;
import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.servlet.auth.oauth2.AbstractAuthorizationCodeCallbackServlet;
import com.google.api.services.oauth2.model.Userinfo;
import com.google.api.client.http.GenericUrl;
import com.github.feitnomore.googleoauth2.redisdatastore.controllers.Oauth2Controller;

public class DoLoginCallback extends AbstractAuthorizationCodeCallbackServlet {

    @Override
    protected AuthorizationCodeFlow initializeFlow() throws IOException {
      return Oauth2Controller.newFlow();
    }
  
    @Override
    protected String getRedirectUri(HttpServletRequest request) {
      GenericUrl url = new GenericUrl(request.getRequestURL().toString());
      url.setRawPath("/doLoginCallback");
      return url.build();
    }
  
    @Override
    protected String getUserId(HttpServletRequest request) {
      return request.getSession().getId();
    }
  
    @Override
    protected void onSuccess(HttpServletRequest request, HttpServletResponse response, Credential credential)
        throws IOException {
          String sessionId = request.getSession().getId();
          Userinfo userInfo = Oauth2Controller.getUserInfo(sessionId);
          if(userInfo.getName().length() > 0) {
            response.sendRedirect("/success");
          } else {
            response.sendRedirect("/needs-login");
          }
    }
  
    @Override
    protected void onError(
        HttpServletRequest request, HttpServletResponse response, AuthorizationCodeResponseUrl errorResponse)
        throws IOException {
      response.getWriter().print("Login cancelled.");
    }
}

• DoLogout.java

import java.io.IOException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DoLogout extends HttpServlet {

  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    request.getSession().invalidate();
    response.sendRedirect("/needs-login");
  }

}