Add Gzip example (segmentio#132)

f2prateek · web-flow · commit a71e0e8f5288 · 2018-08-15T16:15:54.000-07:00
Rather than support gzip natively, I've added an example to show how customers can do this themselves. I'll add this to our public facing docs.
diff --git a/analytics-sample/src/main/java/sample/GzipRequestInterceptor.java b/analytics-sample/src/main/java/sample/GzipRequestInterceptor.java
@@ -0,0 +1,50 @@
+package sample;
+
+import java.io.IOException;
+import okhttp3.*;
+import okio.BufferedSink;
+import okio.GzipSink;
+import okio.Okio;
+
+/**
+ * This interceptor compresses the HTTP request body. Copied from
+ * https://github.com/square/okhttp/wiki/Interceptors#rewriting-requests
+ */
+final class GzipRequestInterceptor implements Interceptor {
+  @Override
+  public Response intercept(Interceptor.Chain chain) throws IOException {
+    Request originalRequest = chain.request();
+    if (originalRequest.body() == null || originalRequest.header("Content-Encoding") != null) {
+      return chain.proceed(originalRequest);
+    }
+
+    Request compressedRequest =
+        originalRequest
+            .newBuilder()
+            .header("Content-Encoding", "gzip")
+            .method(originalRequest.method(), gzip(originalRequest.body()))
+            .build();
+    return chain.proceed(compressedRequest);
+  }
+
+  private RequestBody gzip(final RequestBody body) {
+    return new RequestBody() {
+      @Override
+      public MediaType contentType() {
+        return body.contentType();
+      }
+
+      @Override
+      public long contentLength() {
+        return -1; // We don't know the compressed length in advance!
+      }
+
+      @Override
+      public void writeTo(BufferedSink sink) throws IOException {
+        BufferedSink gzipSink = Okio.buffer(new GzipSink(sink));
+        body.writeTo(gzipSink);
+        gzipSink.close();
+      }
+    };
+  }
+}
diff --git a/analytics-sample/src/main/java/sample/Main.java b/analytics-sample/src/main/java/sample/Main.java
@@ -1,21 +1,26 @@
 package sample;
 
+import com.jakewharton.retrofit.Ok3Client;
 import com.segment.analytics.Analytics;
 import com.segment.analytics.messages.TrackMessage;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+import okhttp3.OkHttpClient;
+import retrofit.client.Client;
 
 public class Main {
   public static void main(String... args) throws Exception {
     final BlockingFlush blockingFlush = BlockingFlush.create();
 
     // https://segment.com/segment-engineering/sources/test-java/debugger
     final Analytics analytics =
-        Analytics.builder("xemyw6oe3n") //
+        Analytics.builder("xemyw6oe3n")
             .plugin(blockingFlush.plugin())
             .plugin(new LoggingPlugin())
+            .client(createClient())
             .build();
 
     final String userId = System.getProperty("user.name");
@@ -27,9 +32,9 @@ public static void main(String... args) throws Exception {
         Map<String, Object> properties = new LinkedHashMap<>();
         properties.put("count", count.incrementAndGet());
         analytics.enqueue(
-            TrackMessage.builder("Java Test") //
-                .properties(properties) //
-                .anonymousId(anonymousId) //
+            TrackMessage.builder("Java Test")
+                .properties(properties)
+                .anonymousId(anonymousId)
                 .userId(userId));
       }
     }
@@ -38,4 +43,19 @@ public static void main(String... args) throws Exception {
     blockingFlush.block();
     analytics.shutdown();
   }
+
+  /**
+   * By default, the analytics client uses an HTTP client with sane defaults. However you can
+   * customize the client to your needs. For instance, this client is configured to automatically
+   * gzip outgoing requests.
+   */
+  private static Client createClient() {
+    return new Ok3Client(
+        new OkHttpClient.Builder()
+            .connectTimeout(15, TimeUnit.SECONDS)
+            .readTimeout(15, TimeUnit.SECONDS)
+            .writeTimeout(15, TimeUnit.SECONDS)
+            .addInterceptor(new GzipRequestInterceptor())
+            .build());
+  }
 }
