Keep quickstart consistent everywhere (#1540)

Author: mayurkale22

examples/BUILD.bazel

@@ -163,8 +163,8 @@ java_binary(
 )
 
 java_binary(
-    name = "StackdriverExample",
-    main_class = "io.opencensus.examples.stats.StackdriverExample",
+    name = "StackdriverQuickstart",
+    main_class = "io.opencensus.examples.stats.StackdriverQuickstart",
     runtime_deps = [
         ":opencensus_examples",
     ],

examples/README.md

@@ -141,21 +141,21 @@ $ prometheus --config.file=prometheus.yaml
 
 Stats will be shown on Prometheus UI on http://localhost:9090.
 
-## To run "StackdriverExample" use
+## To run "StackdriverQuickstart" use
 
 See the full tutorial on [OpenCensus website](https://opencensus.io/guides/exporters/supported-exporters/java/stackdriver/).
 
 ### Gradle
 ```
-$ ./build/install/opencensus-examples/bin/StackdriverExample
+$ ./build/install/opencensus-examples/bin/StackdriverQuickstart
 ```
 
 ### Maven
 ```
-$ ./target/appassembler/bin/StackdriverExample
+$ ./target/appassembler/bin/StackdriverQuickstart
 ```
 
 ### Bazel
 ```
-$ ./bazel-bin/StackdriverExample
+$ ./bazel-bin/StackdriverQuickstart
 ```

examples/build.gradle

@@ -148,9 +148,9 @@ task repl(type: CreateStartScripts) {
     classpath = jar.outputs.files + project.configurations.runtime
 }
 
-task stackdriverStatsExample(type: CreateStartScripts) {
-    mainClassName = 'io.opencensus.examples.stats.StackdriverExample'
-    applicationName = 'StackdriverExample'
+task stackdriverStatsQuickstart(type: CreateStartScripts) {
+    mainClassName = 'io.opencensus.examples.stats.StackdriverQuickstart'
+    applicationName = 'StackdriverQuickstart'
     outputDir = new File(project.buildDir, 'tmp')
     classpath = jar.outputs.files + project.configurations.runtime
 }
@@ -165,6 +165,6 @@ applicationDistribution.into('bin') {
     from(helloWorldServer)
     from(helloWorldClient)
     from(repl)
-    from(stackdriverStatsExample)
+    from(stackdriverStatsQuickstart)
     fileMode = 0755
 }

examples/pom.xml

@@ -147,8 +147,8 @@
               <mainClass>io.opencensus.examples.quickstart.Repl</mainClass>
             </program>
             <program>
-              <id>StackdriverExample</id>
-              <mainClass>io.opencensus.examples.stats.StackdriverExample</mainClass>
+              <id>StackdriverQuickstart</id>
+              <mainClass>io.opencensus.examples.stats.StackdriverQuickstart</mainClass>
             </program>
           </programs>
         </configuration>

examples/src/main/java/io/opencensus/examples/stats/StackdriverExample.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * 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 io.opencensus.examples.stats;
+
+import com.google.common.collect.Lists;
+import io.opencensus.exporter.stats.stackdriver.StackdriverStatsExporter;
+import io.opencensus.stats.Aggregation;
+import io.opencensus.stats.BucketBoundaries;
+import io.opencensus.stats.Measure.MeasureLong;
+import io.opencensus.stats.Stats;
+import io.opencensus.stats.StatsRecorder;
+import io.opencensus.stats.View;
+import io.opencensus.stats.View.Name;
+import io.opencensus.stats.ViewManager;
+import io.opencensus.tags.TagKey;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * StackdriverQuickstart is an example of exporting a custom metric from OpenCensus to Stackdriver.
+ */
+public final class StackdriverQuickstart {
+
+  private static final int EXPORT_INTERVAL = 60;
+  private static final MeasureLong LATENCY_MS =
+      MeasureLong.create("task_latency", "The task latency in milliseconds", "ms");
+  // Latency in buckets:
+  // [>=0ms, >=100ms, >=200ms, >=400ms, >=1s, >=2s, >=4s]
+  private static final BucketBoundaries LATENCY_BOUNDARIES =
+      BucketBoundaries.create(Lists.newArrayList(0d, 100d, 200d, 400d, 1000d, 2000d, 4000d));
+  private static final StatsRecorder STATS_RECORDER = Stats.getStatsRecorder();
+
+  /** Main launcher for the Stackdriver example. */
+  public static void main(String[] args) throws IOException, InterruptedException {
+    // Register the view. It is imperative that this step exists,
+    // otherwise recorded metrics will be dropped and never exported.
+    View view =
+        View.create(
+            Name.create("task_latency_distribution"),
+            "The distribution of the task latencies.",
+            LATENCY_MS,
+            Aggregation.Distribution.create(LATENCY_BOUNDARIES),
+            Collections.<TagKey>emptyList());
+
+    // Create the view manager
+    ViewManager viewManager = Stats.getViewManager();
+
+    // Then finally register the views
+    viewManager.registerView(view);
+
+    // [START setup_exporter]
+    // Enable OpenCensus exporters to export metrics to Stackdriver Monitoring.
+    // Exporters use Application Default Credentials to authenticate.
+    // See https://developers.google.com/identity/protocols/application-default-credentials
+    // for more details.
+    StackdriverStatsExporter.createAndRegister();
+    // [END setup_exporter]
+
+    // Record 100 fake latency values between 0 and 5 seconds.
+    Random rand = new Random();
+    for (int i = 0; i < 100; i++) {
+      long ms = (long) (TimeUnit.MILLISECONDS.convert(5, TimeUnit.SECONDS) * rand.nextDouble());
+      System.out.println(String.format("Latency %d: %d", i, ms));
+      STATS_RECORDER.newMeasureMap().put(LATENCY_MS, ms).record();
+    }
+
+    // The default export interval is 60 seconds. The thread with the StackdriverStatsExporter must
+    // live for at least the interval past any metrics that must be collected, or some risk being
+    // lost if they are recorded after the last export.
+
+    System.out.println(
+        String.format(
+            "Sleeping %d seconds before shutdown to ensure all records are flushed.",
+            EXPORT_INTERVAL));
+    Thread.sleep(TimeUnit.MILLISECONDS.convert(EXPORT_INTERVAL, TimeUnit.SECONDS));
+  }
+}