Adding EventTrigger output binding for sending events to custom topics (#112)

Adding tools-common explicitly.


Adding javadoc comments to the topic fields.

Author: vrdmr

src/main/java/com/microsoft/azure/functions/annotation/EventGridOutput.java

@@ -0,0 +1,78 @@
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for
+ * license information.
+ */
+
+package com.microsoft.azure.functions.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * <p>
+ * Place this on a parameter whose value would come from EventGrid, and causing the method to run when an event is
+ * arrived. The parameter type can be one of the following:</p>
+ *
+ * <ul>
+ *     <li>Any native Java types such as String, byte[]</li>
+ *     <li>Nullable values using Optional&lt;T&gt;</li>
+ *     <li>Any POJO type</li>
+ * </ul>
+ *
+ * <p>The following example shows a Java function that prints out an event and then sends an event to a
+ * custom eventGrid topic:</p>
+ *
+ * <pre>{@literal @}FunctionName("eventGridMonitor")
+ * public void logEvent(
+ *    {@literal @}EventGridTrigger(name = "event") String content,
+ *    {@literal @}EventGridOutput(name = "outputEvent", topicEndpointUri = "MyEventGridTopicUriSetting",
+ *                                topicKeySetting = "MyEventGridTopicKeySetting")
+ *                                      OutputBinding&lt;String&gt; outputEvent
+ *     final ExecutionContext context
+ * ) {
+ *     context.getLogger().info(content);
+ *     final String eventGridOutputDocument = "{\"id\": \"100\", \"eventType\":\"recordInserted\",
+ *         \"subject\": \"myapp/test/java\", \"eventTime\":\"2017-08-10T21:03:07+00:00\",
+ *         \"data\": {\"tag1\": \"value1\",\"tag2\":\"value2\"}, \"dataVersion\": \"1.0\"}";
+ *     outputEvent.setValue(eventGridOutputDocument);
+ * }</pre>
+ *
+ * @since 1.3.1
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.PARAMETER, ElementType.METHOD})
+public @interface EventGridOutput {
+    /**
+     * The variable name used in function.json.
+     * @return The variable name used in function.json.
+     */
+    String name();
+
+    /**
+     * <p>Defines how Functions runtime should treat the parameter value. Possible values are:</p>
+     * <ul>
+     *     <li>"" or string: treat it as a string whose value is serialized from the parameter</li>
+     *     <li>binary: treat it as a binary data whose value comes from for example OutputBinding&lt;byte[]&gt;</li>
+     * </ul>
+     * @return The dataType which will be used by the Functions runtime.
+     */
+    String dataType() default "";
+
+    /**
+     * Gets or sets the Topic Key setting. You can find information on getting the Key for a topic
+     * here: https://docs.microsoft.com/en-us/azure/event-grid/custom-event-quickstart#send-an-event-to-your-topic
+     * @return The topic key setting of the eventGrid topic.
+     */
+    String topicKeySetting();
+
+    /**
+     * Gets or sets the topic events endpoint URI. Eg: https://topic1.westus2-1.eventgrid.azure.net/api/events
+     * This is found in the Event Grid Topic's definition. You can find information on getting the Url for a topic
+     * here: https://docs.microsoft.com/en-us/azure/event-grid/custom-event-quickstart#send-an-event-to-your-topic
+     * @return The topic events endpoint URI of the eventGrid topic.
+     */
+    String topicEndpointUri();
+}