1 files changed, 149 insertions, 0 deletions
diff --git a/src/main/java/com/p4square/restlet/oauth/OAuthHelper.java b/src/main/java/com/p4square/restlet/oauth/OAuthHelper.java
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index 0000000..67dd238
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+++ b/src/main/java/com/p4square/restlet/oauth/OAuthHelper.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.restlet.oauth;
+
+import java.net.URLEncoder;
+
+import org.restlet.Context;
+import org.restlet.Request;
+import org.restlet.Response;
+import org.restlet.Restlet;
+import org.restlet.data.ChallengeResponse;
+import org.restlet.data.ChallengeScheme;
+import org.restlet.data.Form;
+import org.restlet.data.Method;
+import org.restlet.data.Reference;
+import org.restlet.data.Status;
+import org.restlet.engine.Engine;
+import org.restlet.representation.Representation;
+
+/**
+ * Helper Class for OAuth 1.0 Authentication.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public abstract class OAuthHelper {
+    private final Restlet mDispatcher;
+    private final Token mConsumerToken;
+
+    /**
+     * Create a new OAuth Helper.
+     * As currently implemented, there can only be one OAuthHelper per Restlet
+     * Engine since this class registers its own provider for the OAuth
+     * authentication protocol.
+     *
+     * FIXME: This could be improved by making OAuthAuthenticationHelper and
+     * maybe Token aware of multiple service providers.
+     *
+     * @param context The restlet context which provides a ClientDispatcher.
+     * @param consumerKey The OAuth consumer key for this application.
+     * @param consumerSecret the OAuth consumer secret for this application.
+     */
+    public OAuthHelper(Context context, String consumerKey, String consumerSecret) {
+        mDispatcher = context.getClientDispatcher();
+        mConsumerToken = new Token(consumerKey, consumerSecret);
+
+        Engine.getInstance().getRegisteredAuthenticators().add(new OAuthAuthenticatorHelper(mConsumerToken));
+    }
+
+    /**
+     * @return the URL for the initial RequestToken request.
+     */
+    protected abstract String getRequestTokenUrl();
+
+    /**
+     * Request a RequestToken.
+     *
+     * @return a Token containing the RequestToken.
+     * @throws OAuthException if the request fails.
+     */
+    public Token getRequestToken() throws OAuthException {
+        Request request = new Request(Method.GET, getRequestTokenUrl());
+        request.setChallengeResponse(new ChallengeResponse(ChallengeScheme.HTTP_OAUTH));
+
+        Response response = mDispatcher.handle(request);
+
+        return processTokenRequest(response);
+    }
+
+    /**
+     * @return the URL to redirect the user to for Authentication.
+     */
+    public abstract String getLoginUrl(Token requestToken, String callback);
+
+    /**
+     * @return the URL for the AccessToken request.
+     */
+    protected abstract String getAccessTokenUrl();
+
+    /**
+     * Request an AccessToken for a previously authenticated RequestToken.
+     *
+     * @return an OAuthUser object containing the AccessToken.
+     * @throws OAuthException if the request fails.
+     */
+    public OAuthUser getAccessToken(Token requestToken) throws OAuthException {
+        Request request = new Request(Method.GET, getAccessTokenUrl());
+        request.setChallengeResponse(requestToken.getChallengeResponse());
+
+        return processAccessTokenRequest(request);
+    }
+
+    /**
+     * Helper method to decode the token returned from an OAuth Request.
+     *
+     * @param response The Response object from the Request.
+     * @return the Token from the oauth_token and oauth_token_secret parameters.
+     * @throws OAuthException is the server reported an error.
+     */
+    protected Token processTokenRequest(Response response) throws OAuthException {
+        Status status = response.getStatus();
+        Representation entity = response.getEntity();
+
+        try {
+            if (status.isSuccess()) {
+                Form form = new Form(entity);
+                String token = form.getFirstValue("oauth_token");
+                String secret = form.getFirstValue("oauth_token_secret");
+
+                return new Token(token, secret);
+
+            } else {
+                throw new OAuthException(status);
+            }
+        } finally {
+            entity.release();
+        }
+    }
+
+    /**
+     * Helper method to create an OAuthUser from the AccessToken request.
+     *
+     * The User's identifier is set to the Content-Location header, if present.
+     *
+     * @param response The Response to the AccessToken Request.
+     * @return An OAuthUser object wrapping the AccessToken.
+     * @throws OAuthException if the request failed.
+     */
+    public OAuthUser processAccessTokenRequest(Request request) throws OAuthException {
+        Response response = getResponse(request);
+        Token accessToken = processTokenRequest(response);
+
+        Reference ref = response.getEntity().getLocationRef();
+        if (ref != null) {
+            return new OAuthUser(ref.toString(), accessToken);
+
+        } else {
+            return new OAuthUser(accessToken);
+        }
+    }
+
+    /**
+     * Helper method to get a Response for a Request.
+     */
+    public Response getResponse(Request request) {
+        return mDispatcher.handle(request);
+    }
+}