samples: add webhook sample (#730)

* samples:add webhook sample

* Revised Code

* Changed class name to match cloud function

* Revised code

* Changed Test

* Fixed test

* Test Fix

* changed json " to '

* added bracket

* lint fix

* 🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

dialogflow/snippets/src/main/dialogflow/Example.java

@@ -0,0 +1,48 @@
+package com.example;
+
+import com.google.cloud.functions.HttpFunction;
+import com.google.cloud.functions.HttpRequest;
+import com.google.cloud.functions.HttpResponse;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import java.io.BufferedWriter;
+
+public class Example implements HttpFunction {
+
+  public void service(HttpRequest request, HttpResponse response) throws Exception {
+    JsonParser parser = new JsonParser();
+    Gson gson = new GsonBuilder().create();
+
+    JsonObject job = gson.fromJson(request.getReader(), JsonObject.class);
+    String str =
+        job.getAsJsonObject("queryResult")
+            .getAsJsonObject("intent")
+            .getAsJsonPrimitive("displayName")
+            .toString();
+    JsonObject o = null;
+    String a = '"' + "Default Welcome Intent" + '"';
+    String b = '"' + "get-agent-name" + '"';
+    String responseText = "";
+
+    if (str.equals(a)) {
+      responseText = '"' + "Hello from a Java GCF Webhook" + '"';
+    } else if (str.equals(b)) {
+      responseText = '"' + "My name is Flowhook" + '"';
+    } else {
+      responseText = '"' + "Sorry I didn't get that" + '"';
+    }
+
+    o =
+        parser
+            .parse(
+                "{\"fulfillmentMessages\": [ { \"text\": { \"text\": [ "
+                    + responseText
+                    + " ] } } ] }")
+            .getAsJsonObject();
+
+    BufferedWriter writer = response.getWriter();
+    writer.write(o.toString());
+  }
+}

dialogflow/snippets/src/test/dialogflow/ExampleIT.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package dialogflow.cx;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.when;
+
+import com.google.cloud.functions.HttpRequest;
+import com.google.cloud.functions.HttpResponse;
+import com.google.gson.Gson;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class ExampleIT {
+  @Mock private HttpRequest request;
+  @Mock private HttpResponse response;
+
+  private BufferedWriter writerOut;
+  private StringWriter responseOut;
+  private static final Gson gson = new Gson();
+
+  @Before
+  public void beforeTest() throws IOException {
+    MockitoAnnotations.initMocks(this);
+
+    // use an empty string as the default request content
+    BufferedReader reader = new BufferedReader(new StringReader(""));
+    when(request.getReader()).thenReturn(reader);
+
+    responseOut = new StringWriter();
+    writerOut = new BufferedWriter(responseOut);
+    when(response.getWriter()).thenReturn(writerOut);
+  }
+
+  @Test
+  public void helloHttp_bodyParamsPost() throws IOException {
+    BufferedReader jsonReader =
+        new BufferedReader(
+            new StringReader(
+                "{'queryResult': { 'intent': { 'name': 'projects', 'displayName': 'Default Welcome Intent' } } })"));
+
+    when(request.getReader()).thenReturn(jsonReader);
+
+    new Webhook().service(request, response);
+    writerOut.flush();
+
+    assertThat(responseOut.toString()).contains("Hello from a Java GCF Webhook");
+  }
+}

dialogflow/snippets/src/test/dialogflow/SetAgentIT.java

@@ -20,7 +20,6 @@
 import org.junit.Test;
 
 public class SetAgentIT {
-
   /*
    * We cannot test setAgent because Dialogflow ES can only have one agent
    * and if we create a agent it will delete the exisitng testing agent and