Home.java

package com.appspot.dangt85.controllers;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller

public class Home {
	private static final String ACCESS_TOKEN = "ACCESS_TOKEN";
	private static final String INSTANCE_URL = "INSTANCE_URL";

	// clientId is 'Consumer Key' in the Remote Access UI
	private static String clientId = "";
	// clientSecret is 'Consumer Secret' in the Remote Access UI
	private static String clientSecret = "";
	// This must be identical to 'Callback URL' in the Remote Access UI
	private static String redirectUri = "https://localhost:8443/auth/salesforce/callback";
	private static String environment = "https://login.salesforce.com";
	private String authUrl = null;
	private String tokenUrl = null;
	
	@RequestMapping(value = "/")
	@ResponseBody
	public String home() {
		
		return "<a href=\"/auth/salesforce\">login</a>";
	}
	
	@RequestMapping(value = "/auth/salesforce")
	public String authenticate(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		String accessToken = (String) request.getSession().getAttribute(
				ACCESS_TOKEN);
		
		if(accessToken == null) {
		
			try {
				authUrl = environment
						+ "/services/oauth2/authorize?response_type=code&client_id="
						+ clientId + "&redirect_uri="
						+ URLEncoder.encode(redirectUri, "UTF-8");
			} catch (UnsupportedEncodingException e) {
				throw new ServletException(e);
			}
	
			return "redirect:" + authUrl;
		} else {
			return "redirect:/auth/salesforce/callback";
		}
	}
	
	@RequestMapping(value = "/auth/salesforce/callback")
	@ResponseBody
	public String authenticateCallback(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		String accessToken = (String) request.getSession().getAttribute(
				ACCESS_TOKEN);
		
		if(accessToken == null) {
			String instanceUrl = null;
			
			tokenUrl = environment + "/services/oauth2/token";
			
			String code = request.getParameter("code");

			HttpClient httpclient = new HttpClient();

			PostMethod post = new PostMethod(tokenUrl);
			post.addParameter("code", code);
			post.addParameter("grant_type", "authorization_code");
			post.addParameter("client_id", clientId);
			post.addParameter("client_secret", clientSecret);
			post.addParameter("redirect_uri", redirectUri);

			try {
				httpclient.executeMethod(post);

				try {
					JSONObject authResponse = new JSONObject(
							new JSONTokener(new InputStreamReader(
									post.getResponseBodyAsStream())));
					System.out.println("Auth response: "
							+ authResponse.toString(2));

					accessToken = authResponse.getString("access_token");
					instanceUrl = authResponse.getString("instance_url");

				} catch (JSONException e) {
					e.printStackTrace();
					throw new ServletException(e);
				}
			} finally {
				post.releaseConnection();
			}
			// Set a session attribute so that other servlets can get the access
			// token
			request.getSession().setAttribute(ACCESS_TOKEN, accessToken);
			
			// We also get the instance URL from the OAuth response, so set it
			// in the session too
			request.getSession().setAttribute(INSTANCE_URL, instanceUrl);
		}

		return "Logged in! <a href=\"/logout\">Log out</a> | "
				+ "<a href=\"/accounts\">Get accounts</a> | "
				+ "Got access token: " + accessToken;
	}
	
	@RequestMapping(value = "/logout")
	@ResponseBody
	public String logout(HttpServletRequest request) {
		HttpSession session = request.getSession();
		
		session.removeAttribute(ACCESS_TOKEN);
		session.removeAttribute(INSTANCE_URL);
		
		return "logged out! <a href=\"/auth/salesforce\">login</a>";
	}
	
	@RequestMapping(value = "/accounts")
	@ResponseBody
	public String accounts(HttpServletRequest request) throws ServletException{
		HttpSession session = request.getSession();
		
		String accessToken = (String)session.getAttribute(ACCESS_TOKEN);
		String instanceUrl = (String)session.getAttribute(INSTANCE_URL);
		
		if (accessToken == null) {
			return "<a href=\"/logout\">Log out</a> | Error - no access token";
		}
		
		StringBuffer writer = new StringBuffer();

		writer.append("We have an access token: " + accessToken + "<br />"
				+ "Using instance " + instanceUrl + "<br /><br />");

		HttpClient httpclient = new HttpClient();
		GetMethod get = new GetMethod(instanceUrl
				+ "/services/data/v20.0/query");

		// set the token in the header
		get.setRequestHeader("Authorization", "OAuth " + accessToken);

		// set the SOQL as a query param
		NameValuePair[] params = new NameValuePair[1];

		params[0] = new NameValuePair("q",
				"SELECT Id, Name from Account LIMIT 100");
		get.setQueryString(params);

		try {
			httpclient.executeMethod(get);
			if (get.getStatusCode() == HttpStatus.SC_OK) {
				// Now lets use the standard java json classes to work with the
				// results
				try {
					JSONObject response = new JSONObject(
							new JSONTokener(new InputStreamReader(
									get.getResponseBodyAsStream())));
					System.out.println("Query response: "
							+ response.toString(2));

					writer.append(response.getString("totalSize")
							+ " record(s) returned<br /><br />");

					JSONArray results = response.getJSONArray("records");

					for (int i = 0; i < results.length(); i++) {
						writer.append(results.getJSONObject(i).getString("Id")
								+ ", "
								+ results.getJSONObject(i).getString("Name")
								+ "<br />");
					}
					writer.append("<br />");
				} catch (JSONException e) {
					e.printStackTrace();
					throw new ServletException(e);
				} catch (IOException e) {
					e.printStackTrace();
					throw new ServletException(e);
				}
			}
		} catch (HttpException e) {
			e.printStackTrace();
			throw new ServletException(e);
		} catch (IOException e) {
			e.printStackTrace();
			throw new ServletException(e);
		} finally {
			get.releaseConnection();
		}
		
		return writer.toString();
	}
}