Checkstyle fixes in Cloud Storage JSON API tests.

Getting ready to use shared java-repo-tools configuration.

I also convert the assertions to use
[truth](http://google.github.io/truth/).

Since I find it more readable to get a list of object names first
instead of manually looping through, I also update the sample to use
Java 8 lambdas to extract these object names. The sample is used here:
https://cloud.google.com/storage/docs/json_api/v1/json-api-java-samples
which does not indicate the required Java version.

storage/json-api/pom.xml

@@ -12,6 +12,12 @@
   <artifactId>storage-json-sample</artifactId>
   <version>1</version>
   <name>Sample accessing the Google Cloud Storage JSON API using OAuth 2.0.</name>
+
+  <properties>
+      <maven.compiler.target>1.8</maven.compiler.target>
+      <maven.compiler.source>1.8</maven.compiler.source>
+  </properties>
+
   <build>
     <plugins>
       <plugin>
@@ -45,5 +51,11 @@
       <version>4.10</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.truth</groupId>
+      <artifactId>truth</artifactId>
+      <version>0.28</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 </project>

storage/json-api/src/test/java/StorageSampleTest.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2015 Google Inc. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,16 +16,16 @@
 
 // [START all]
 
-import static org.junit.Assert.*;
+import static com.google.common.truth.Truth.assertThat;
 
 import com.google.api.services.storage.model.Bucket;
 import com.google.api.services.storage.model.StorageObject;
 
 import org.junit.Test;
 
-import java.util.List;
-import java.util.regex.Pattern;
 import java.io.ByteArrayInputStream;
+import java.util.List;
+import java.util.stream.Collectors;
 
 public class StorageSampleTest {
   private static final String BUCKET = "cloud-samples-tests";
@@ -34,49 +34,37 @@ public class StorageSampleTest {
   @Test
   public void testListBucket() throws Exception {
     List<StorageObject> listing = StorageSample.listBucket(BUCKET);
-    assertTrue(listing.size() > 0);
+    assertThat(listing).isNotEmpty();
   }
 
   @Test
   public void testGetBucket() throws Exception {
     Bucket bucket = StorageSample.getBucket(BUCKET);
-    assertEquals(bucket.getName(), BUCKET);
-    assertEquals(bucket.getLocation(), "US-CENTRAL1");
+    assertThat(bucket.getName()).named("bucket name").isEqualTo(BUCKET);
+    assertThat(bucket.getLocation()).named("bucket location").isEqualTo("US-CENTRAL1");
   }
 
   @Test
   public void testUploadDelete() throws Exception {
     StorageSample.uploadStream(
         TEST_OBJECT, "text/plain",
-        new ByteArrayInputStream(("This object is uploaded and deleted as part of the "
+        new ByteArrayInputStream(
+            ("This object is uploaded and deleted as part of the "
             + "StorageSampleTest integration test.").getBytes()),
         BUCKET);
 
     try {
       // Verify that the object was created
       List<StorageObject> listing = StorageSample.listBucket(BUCKET);
-      boolean found = false;
-      for (StorageObject so : listing) {
-        if (TEST_OBJECT.equals(so.getName())) {
-          found = true;
-          break;
-        }
-      }
-      assertTrue("Should have uploaded successfully", found);
-
+      List<String> names = listing.stream().map(so -> so.getName()).collect(Collectors.toList());
+      assertThat(names).named("objects found after upload").contains(TEST_OBJECT);
     } finally {
       StorageSample.deleteObject(TEST_OBJECT, BUCKET);
 
       // Verify that the object no longer exists
       List<StorageObject> listing = StorageSample.listBucket(BUCKET);
-      boolean found = false;
-      for (StorageObject so : listing) {
-        if (TEST_OBJECT.equals(so.getName())) {
-          found = true;
-          break;
-        }
-      }
-      assertFalse("Object (" + TEST_OBJECT + ") should have been deleted", found);
+      List<String> names = listing.stream().map(so -> so.getName()).collect(Collectors.toList());
+      assertThat(names).named("objects found after delete").doesNotContain(TEST_OBJECT);
     }
   }
 }