Update PR comment. Add README file

APPENGINE.md

@@ -0,0 +1,33 @@
+Use Google Cloud Java Client with GoogleAppEngine
+=================================================
+
+Quickstart
+----------
+This file provides extra instructions to setup Google Cloud Java client with GoogleAppEngine.
+See [Quickstart](./README.md#quickstart) for Google Cloud Java common instructions.
+See [Quickstart](https://cloud.google.com/appengine/docs/standard/java/quickstart) for extra GAE instructions.
+
+git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git
+
+If you are using Maven, add this to your pom.xml file
+```xml
+<dependency>
+    <groupId>com.google.appengine</groupId>
+    <artifactId>appengine-api-1.0-sdk</artifactId>
+    <version>1.9.50</version>
+</dependency>
+```
+
+If you are using Gradle, add this to your dependencies
+```Groovy
+compile 'com.google.appengine:appengine-api-1.0-sdk:1.9.50'
+```
+If you are using SBT, add this to your dependencies
+```Scala
+libraryDependencies += "com.google.appengine" % "appengine-api-1.0-sdk" % "1.9.50"
+```
+
+To test with local dev server, run
+```
+mvn appengine:devserver
+```

README.md

@@ -57,6 +57,8 @@ If you are using SBT, add this to your dependencies
 libraryDependencies += "com.google.cloud" % "google-cloud" % "0.9.4-alpha"
 ```
 
+For GoogleAppEngine use case, see [more instructions here](./APPENGINE.md).
+
 Example Applications
 --------------------
 

google-cloud-core/src/main/java/com/google/cloud/ServiceOptions.java

@@ -397,7 +397,8 @@ protected static String getAppEngineProjectId() {
     } catch (Exception exception) {
       if (System.getProperty("com.google.appengine.runtime.version") != null) {
         // Could not resolve appengine classes under GAE environment.
-        throw new RuntimeException("Unable to resolve appengine classes. Missing dependency.");
+        throw new RuntimeException("Unable to resolve appengine-sdk classes. For more details see "
+            + "https://github.com/GoogleCloudPlatform/google-cloud-java/blob/master/APPENGINE.md");
       }
       return null;
     }