cleanup + cast fix

Author: Ajay Kannan

gcloud-java-core/src/main/java/com/google/gcloud/AuthCredentials.java

@@ -46,7 +46,6 @@ private static class AppEngineCredentials extends GoogleCredentials {
       private final Method getAccessToken;
       private final Method getAccessTokenResult;
       private final Collection<String> scopes;
-      private final boolean scopesRequired;
 
       AppEngineCredentials() {
         try {
@@ -61,19 +60,16 @@ private static class AppEngineCredentials extends GoogleCredentials {
           this.getAccessTokenResult = serviceClass.getMethod("getAccessToken", Iterable.class);
           this.getAccessToken = tokenResultClass.getMethod("getAccessToken");
           this.scopes = null;
-          this.scopesRequired = true;
         } catch (Exception e) {
-          throw new RuntimeException("Could not create AppEngineCredentials using reflection.");
+          throw new RuntimeException("Could not create AppEngineCredentials.", e);
         }
       }
 
-      AppEngineCredentials(Collection<String> scopes, Object appIdentityService,
-          Method getAccessToken, Method getAccessTokenResult) {
-        this.appIdentityService = appIdentityService;
-        this.getAccessToken = getAccessToken;
-        this.getAccessTokenResult = getAccessTokenResult;
+      AppEngineCredentials(Collection<String> scopes, AppEngineCredentials unscoped) {
+        this.appIdentityService = unscoped.appIdentityService;
+        this.getAccessToken = unscoped.getAccessToken;
+        this.getAccessTokenResult = unscoped.getAccessTokenResult;
         this.scopes = scopes;
-        this.scopesRequired = (scopes == null || scopes.isEmpty());
       }
 
       /**
@@ -89,19 +85,18 @@ public AccessToken refreshAccessToken() throws IOException {
           String accessToken = (String) getAccessToken.invoke(accessTokenResult);
           return new AccessToken(accessToken, null);
         } catch (Exception e) {
-          throw new RuntimeException("Could not get the access token using reflection.");
+          throw new IOException("Could not get the access token.", e);
         }
       }
 
       @Override
       public boolean createScopedRequired() {
-        return scopesRequired;
+        return scopes == null || scopes.isEmpty();
       }
 
       @Override
       public GoogleCredentials createScoped(Collection<String> scopes) {
-        return new AppEngineCredentials(
-            scopes, appIdentityService, getAccessToken, getAccessTokenResult);
+        return new AppEngineCredentials(scopes, this);
       }
     }
 
@@ -308,6 +303,7 @@ public static ServiceAccountAuthCredentials createForJson(InputStream jsonCreden
           tempServiceAccountCredentials.getClientEmail(),
           tempServiceAccountCredentials.getPrivateKey());
     }
-    throw new IOException("The given JSON Credentials Stream is not a service account credential.");
+    throw new IOException(
+        "The given JSON Credentials Stream is not for a service account credential.");
   }
 }

gcloud-java-storage/src/main/java/com/google/gcloud/storage/StorageImpl.java

@@ -562,16 +562,18 @@ public URL signUrl(BlobInfo blobInfo, long duration, TimeUnit unit, SignUrlOptio
     for (SignUrlOption option : options) {
       optionMap.put(option.option(), option.value());
     }
-    ServiceAccountAuthCredentials cred =
+    ServiceAccountAuthCredentials serviceAccountAuthCred =
         (ServiceAccountAuthCredentials) optionMap.get(SignUrlOption.Option.SERVICE_ACCOUNT_CRED);
-    if (cred == null) {
-      AuthCredentials authCredentials = this.options().authCredentials();
+    ServiceAccountCredentials cred = (ServiceAccountCredentials) (serviceAccountAuthCred != null
+        ? serviceAccountAuthCred.credentials() : null);
+    if (serviceAccountAuthCred == null) {
+      AuthCredentials authCred = this.options().authCredentials();
       GoogleCredentials serviceCred =
-          authCredentials != null ? authCredentials.credentials() : null;
+          authCred != null ? authCred.credentials() : null;
       checkArgument(
           serviceCred instanceof ServiceAccountCredentials,
           "Signing key was not provided and could not be derived");
-      cred = (ServiceAccountAuthCredentials) authCredentials;
+      cred = (ServiceAccountCredentials) serviceCred;
     }
     // construct signature - see https://cloud.google.com/storage/docs/access-control#Signed-URLs
     StringBuilder stBuilder = new StringBuilder();
@@ -607,12 +609,12 @@ public URL signUrl(BlobInfo blobInfo, long duration, TimeUnit unit, SignUrlOptio
     stBuilder.append(path);
     try {
       Signature signer = Signature.getInstance("SHA256withRSA");
-      signer.initSign(cred.privateKey());
+      signer.initSign(cred.getPrivateKey());
       signer.update(stBuilder.toString().getBytes(UTF_8));
       String signature =
           URLEncoder.encode(BaseEncoding.base64().encode(signer.sign()), UTF_8.name());
       stBuilder = new StringBuilder("https://storage.googleapis.com").append(path);
-      stBuilder.append("?GoogleAccessId=").append(cred.account());
+      stBuilder.append("?GoogleAccessId=").append(cred.getClientEmail());
       stBuilder.append("&Expires=").append(expiration);
       stBuilder.append("&Signature=").append(signature);
       return new URL(stBuilder.toString());