Add NoCredentials class and remove setNoCredentials method

TESTING.md

@@ -102,7 +102,7 @@ You can test against a remote Datastore emulator as well.  To do this, set the `
   DatastoreOptions options = DatastoreOptions.newBuilder()
       .setProjectId("my-project-id") // must match project ID specified on remote machine
       .setHost("http://<hostname of machine>:<port>")
-      .setNoCredentials()
+      .setCredentials(NoCredentials.getInstance())
       .build();
   Datastore localDatastore = options.getService();
   ```
@@ -209,7 +209,7 @@ endpoint to the hostname of the remote machine, like the example below.
   PubSubOptions options = PubSubOptions.newBuilder()
       .setProjectId("my-project-id") // must match project ID specified on remote machine
       .setHost("<hostname of machine>:<port>")
-      .setNoCredentials()
+      .setCredentials(NoCredentials.getInstance())
       .build();
   PubSub localPubsub = options.getService();
   ```

google-cloud-bigquery/src/test/java/com/google/cloud/bigquery/SerializationTest.java

@@ -17,6 +17,7 @@
 package com.google.cloud.bigquery;
 
 import com.google.cloud.BaseSerializationTest;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.bigquery.StandardTableDefinition.StreamingBuffer;
 import com.google.common.collect.ImmutableList;
@@ -228,7 +229,7 @@ public class SerializationTest extends BaseSerializationTest {
   protected Serializable[] serializableObjects() {
     BigQueryOptions options = BigQueryOptions.newBuilder()
         .setProjectId("p1")
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .build();
     BigQueryOptions otherOptions = options.toBuilder().setProjectId("p2").build();
     return new Serializable[]{DOMAIN_ACCESS, GROUP_ACCESS, USER_ACCESS, VIEW_ACCESS, DATASET_ID,

google-cloud-compute/src/test/java/com/google/cloud/compute/SerializationTest.java

@@ -17,6 +17,7 @@
 package com.google.cloud.compute;
 
 import com.google.cloud.BaseSerializationTest;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.RetryParams;
 import com.google.cloud.compute.AttachedDisk.CreateDiskConfiguration;
@@ -264,7 +265,7 @@ public class SerializationTest extends BaseSerializationTest {
   protected Serializable[] serializableObjects() {
     ComputeOptions options = ComputeOptions.newBuilder()
         .setProjectId("p1")
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .build();
     ComputeOptions otherOptions = options.toBuilder()
         .setProjectId("p2")

google-cloud-core/src/main/java/com/google/cloud/GrpcServiceOptions.java

@@ -320,7 +320,7 @@ protected ConnectionSettings.Builder getConnectionSettings() {
         .setServiceAddress(hostAndPort.getHostText())
         .setPort(hostAndPort.getPort());
     Credentials scopedCredentials = getScopedCredentials();
-    if (scopedCredentials != null) {
+    if (scopedCredentials != null && scopedCredentials != NoCredentials.getInstance()) {
       builder.provideCredentialsWith(scopedCredentials);
     }
     return builder;

google-cloud-core/src/main/java/com/google/cloud/HttpServiceOptions.java

@@ -215,7 +215,8 @@ public HttpRequestInitializer httpRequestInitializer() {
   public HttpRequestInitializer getHttpRequestInitializer() {
     Credentials scopedCredentials = getScopedCredentials();
     final HttpRequestInitializer delegate =
-        scopedCredentials != null ? new HttpCredentialsAdapter(scopedCredentials) : null;
+        scopedCredentials != null && scopedCredentials != NoCredentials.getInstance()
+            ? new HttpCredentialsAdapter(scopedCredentials) : null;
     return new HttpRequestInitializer() {
       @Override
       public void initialize(HttpRequest httpRequest) throws IOException {

google-cloud-core/src/main/java/com/google/cloud/NoCredentials.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2016 Google Inc. All Rights Reserved.
+ *
+ * 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 com.google.cloud;
+
+import com.google.auth.oauth2.OAuth2Credentials;
+
+import java.io.ObjectStreamException;
+
+/**
+ * A placeholder for credentials to signify that requests sent to the server should not be
+ * authenticated. This is typically useful when using local service emulators.
+ */
+public class NoCredentials extends OAuth2Credentials {
+
+  private static final long serialVersionUID = -6263971603971044288L;
+  private static final NoCredentials INSTANCE = new NoCredentials();
+
+  private NoCredentials() {}
+
+  private Object readResolve() throws ObjectStreamException {
+    return INSTANCE;
+  }
+
+  public static NoCredentials getInstance() {
+    return INSTANCE;
+  }
+}

google-cloud-core/src/main/java/com/google/cloud/ServiceOptions.java

@@ -84,7 +84,6 @@ public abstract class ServiceOptions<ServiceT extends Service<OptionsT>, Service
   private final String serviceRpcFactoryClassName;
   private final String serviceFactoryClassName;
   private final Clock clock;
-  private final boolean noCredentials;
   private final Credentials credentials;
 
   private transient ServiceRpcFactory<ServiceRpcT, OptionsT> serviceRpcFactory;
@@ -106,7 +105,6 @@ protected abstract static class Builder<ServiceT extends Service<OptionsT>, Serv
 
     private String projectId;
     private String host;
-    private boolean noCredentials;
     private Credentials credentials;
     private RetryParams retryParams;
     private ServiceFactory<ServiceT, OptionsT> serviceFactory;
@@ -118,7 +116,6 @@ protected Builder() {}
     protected Builder(ServiceOptions<ServiceT, ServiceRpcT, OptionsT> options) {
       projectId = options.projectId;
       host = options.host;
-      noCredentials = options.noCredentials;
       credentials = options.credentials;
       retryParams = options.retryParams;
       serviceFactory = options.serviceFactory;
@@ -214,29 +211,18 @@ public B setHost(String host) {
     }
 
     /**
-     * Sets the service authentication credentials. If this method or {@link #setNoCredentials() are
-     * not used on the builder, {@link GoogleCredentials#getApplicationDefault()} will be used to
-     * attempt getting credentials from the environment.
+     * Sets the service authentication credentials. If no credentials are set,
+     * {@link GoogleCredentials#getApplicationDefault()} will be used to attempt getting credentials
+     * from the environment. Use {@link NoCredentials#getInstance()} to skip authentication, this is
+     * typically useful when using local service emulators.
      *
      * @param credentials authentication credentials, should not be {@code null}
      * @return the builder
      * @throws NullPointerException if {@code credentials} is {@code null}. To disable
-     *     authentication use {@link Builder#setNoCredentials()}
+     *     authentication use {@link NoCredentials#getInstance()}
      */
     public B setCredentials(Credentials credentials) {
       this.credentials = checkNotNull(credentials);
-      this.noCredentials = false;
-      return self();
-    }
-
-    /**
-     * Sets that no credentials should be used. This is typically useful when using the local
-     * service emulators, such as {@code LocalDatastoreHelper}, {@code LocalPubsubHelper} and
-     * {@code LocalResourceManagerHelper}.
-     */
-    public B setNoCredentials() {
-      this.noCredentials = true;
-      this.credentials = null;
       return self();
     }
 
@@ -296,9 +282,7 @@ protected ServiceOptions(Class<? extends ServiceFactory<ServiceT, OptionsT>> ser
           + "or the environment.  Please set a project ID using the builder.");
     }
     host = firstNonNull(builder.host, getDefaultHost());
-    noCredentials = builder.noCredentials;
-    credentials = builder.credentials != null || noCredentials
-        ? builder.credentials : defaultCredentials();
+    credentials = builder.credentials != null ? builder.credentials : defaultCredentials();
     retryParams = firstNonNull(builder.retryParams, defaultRetryParams());
     serviceFactory = firstNonNull(builder.serviceFactory,
         getFromServiceLoader(serviceFactoryClass, getDefaultServiceFactory()));
@@ -540,8 +524,8 @@ public Credentials getCredentials() {
    */
   public Credentials getScopedCredentials() {
     Credentials credentialsToReturn = credentials;
-    if (credentials instanceof GoogleCredentials &&
-        ((GoogleCredentials) credentials).createScopedRequired()) {
+    if (credentials instanceof GoogleCredentials
+        && ((GoogleCredentials) credentials).createScopedRequired()) {
       credentialsToReturn = ((GoogleCredentials) credentials).createScoped(getScopes());
     }
     return credentialsToReturn;
@@ -626,13 +610,12 @@ public String getLibraryVersion() {
   }
 
   protected int baseHashCode() {
-    return Objects.hash(projectId, host, noCredentials, credentials, retryParams,
-        serviceFactoryClassName, serviceRpcFactoryClassName, clock);
+    return Objects.hash(projectId, host, credentials, retryParams, serviceFactoryClassName,
+        serviceRpcFactoryClassName, clock);
   }
 
   protected boolean baseEquals(ServiceOptions<?, ?, ?> other) {
-    return noCredentials == other.noCredentials
-        && Objects.equals(projectId, other.projectId)
+    return Objects.equals(projectId, other.projectId)
         && Objects.equals(host, other.host)
         && Objects.equals(credentials, other.credentials)
         && Objects.equals(retryParams, other.retryParams)

google-cloud-core/src/test/java/com/google/cloud/ServiceOptionsTest.java

@@ -84,7 +84,7 @@ public class ServiceOptionsTest {
           .build();
   private static final TestServiceOptions OPTIONS_NO_CREDENTIALS =
       TestServiceOptions.newBuilder()
-          .setNoCredentials()
+          .setCredentials(NoCredentials.getInstance())
           .setClock(TEST_CLOCK)
           .setHost("host")
           .setProjectId("project-id")
@@ -224,7 +224,7 @@ public void testBuilder() {
 
   @Test
   public void testBuilderNoCredentials() {
-    assertNull(OPTIONS_NO_CREDENTIALS.getCredentials());
+    assertEquals(NoCredentials.getInstance(), OPTIONS_NO_CREDENTIALS.getCredentials());
     assertSame(TEST_CLOCK, OPTIONS_NO_CREDENTIALS.getClock());
     assertEquals("host", OPTIONS_NO_CREDENTIALS.getHost());
     assertEquals("project-id", OPTIONS_NO_CREDENTIALS.getProjectId());

google-cloud-datastore/src/main/java/com/google/cloud/datastore/testing/LocalDatastoreHelper.java

@@ -19,6 +19,7 @@
 import static com.google.common.base.MoreObjects.firstNonNull;
 import static com.google.common.base.Preconditions.checkArgument;
 
+import com.google.cloud.NoCredentials;
 import com.google.cloud.RetryParams;
 import com.google.cloud.datastore.DatastoreOptions;
 import com.google.common.base.Strings;
@@ -639,7 +640,7 @@ private DatastoreOptions.Builder optionsBuilder() {
     return DatastoreOptions.newBuilder()
         .setProjectId(projectId)
         .setHost("localhost:" + Integer.toString(port))
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .setRetryParams(RetryParams.noRetries());
   }
 

google-cloud-datastore/src/test/java/com/google/cloud/datastore/SerializationTest.java

@@ -19,6 +19,7 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.cloud.BaseSerializationTest;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.datastore.StructuredQuery.CompositeFilter;
 import com.google.cloud.datastore.StructuredQuery.OrderBy;
@@ -110,7 +111,7 @@ public class SerializationTest extends BaseSerializationTest {
   @Override
   protected java.io.Serializable[] serializableObjects() {
     DatastoreOptions options = DatastoreOptions.newBuilder()
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .setProjectId("ds1")
         .build();
     DatastoreOptions otherOptions = options.toBuilder().setNamespace("ns1").build();

google-cloud-datastore/src/test/java/com/google/cloud/datastore/testing/LocalDatastoreHelperTest.java

@@ -22,6 +22,7 @@
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
+import com.google.cloud.NoCredentials;
 import com.google.cloud.datastore.Datastore;
 import com.google.cloud.datastore.DatastoreException;
 import com.google.cloud.datastore.DatastoreOptions;
@@ -72,11 +73,11 @@ public void testOptions() {
     DatastoreOptions options = helper.getOptions();
     assertTrue(options.getProjectId().startsWith(PROJECT_ID_PREFIX));
     assertTrue(options.getHost().startsWith("localhost:"));
-    assertNull(options.getCredentials());
+    assertSame(NoCredentials.getInstance(), options.getCredentials());
     options = helper.getOptions(NAMESPACE);
     assertTrue(options.getProjectId().startsWith(PROJECT_ID_PREFIX));
     assertTrue(options.getHost().startsWith("localhost:"));
-    assertNull(options.getCredentials());
+    assertSame(NoCredentials.getInstance(), options.getCredentials());
     assertEquals(NAMESPACE, options.getNamespace());
   }
 

google-cloud-dns/src/main/java/com/google/cloud/dns/testing/LocalDnsHelper.java

@@ -28,6 +28,7 @@
 import com.google.api.services.dns.model.Project;
 import com.google.api.services.dns.model.Quota;
 import com.google.api.services.dns.model.ResourceRecordSet;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.dns.DnsOptions;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
@@ -506,7 +507,7 @@ public DnsOptions getOptions() {
     return DnsOptions.newBuilder()
         .setProjectId(PROJECT_ID)
         .setHost("http://localhost:" + port)
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .build();
   }
 

google-cloud-dns/src/test/java/com/google/cloud/dns/SerializationTest.java

@@ -17,6 +17,7 @@
 package com.google.cloud.dns;
 
 import com.google.cloud.BaseSerializationTest;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.RetryParams;
 import com.google.common.collect.ImmutableList;
@@ -88,7 +89,7 @@ public class SerializationTest extends BaseSerializationTest {
   @Override
   protected Serializable[] serializableObjects() {
     DnsOptions options = DnsOptions.newBuilder()
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .setProjectId("id1")
         .build();
     DnsOptions otherOptions = options.toBuilder().build();

google-cloud-logging/src/test/java/com/google/cloud/logging/SerializationTest.java

@@ -18,6 +18,7 @@
 
 import com.google.cloud.BaseSerializationTest;
 import com.google.cloud.MonitoredResource;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.logging.Logging.EntryListOption;
 import com.google.cloud.logging.Logging.ListOption;
@@ -40,7 +41,7 @@ public class SerializationTest extends BaseSerializationTest {
 
   private static final Logging LOGGING = LoggingOptions.newBuilder()
       .setProjectId("p")
-      .setNoCredentials()
+      .setCredentials(NoCredentials.getInstance())
       .setHost("localhost")
       .build().getService();
   private static final HttpRequest HTTP_REQUEST = HttpRequest.newBuilder()

google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/testing/LocalPubsubHelper.java

@@ -19,6 +19,7 @@
 import com.google.api.gax.testing.DownloadableEmulatorRunner;
 import com.google.api.gax.testing.GCloudEmulatorRunner;
 import com.google.api.gax.testing.LocalServiceHelper;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.RetryParams;
 import com.google.cloud.pubsub.PubSubOptions;
 
@@ -157,7 +158,7 @@ public PubSubOptions getOptions() {
     return PubSubOptions.newBuilder()
         .setProjectId(projectId)
         .setHost("localhost:" + port)
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .setRetryParams(RetryParams.noRetries())
         .build();
   }

google-cloud-pubsub/src/test/java/com/google/cloud/pubsub/SerializationTest.java

@@ -18,6 +18,7 @@
 
 import com.google.cloud.BaseSerializationTest;
 import com.google.cloud.GrpcServiceOptions.ExecutorFactory;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.Restorable;
 import com.google.cloud.pubsub.PubSub.ListOption;
 import com.google.cloud.pubsub.PubSub.PullOption;
@@ -29,7 +30,7 @@ public class SerializationTest extends BaseSerializationTest {
 
   private static final PubSub PUB_SUB = PubSubOptions.newBuilder()
       .setProjectId("p")
-      .setNoCredentials()
+      .setCredentials(NoCredentials.getInstance())
       .setHost("localhost")
       .build().getService();
   private static final Message MESSAGE = Message.of("payload");

google-cloud-resourcemanager/src/main/java/com/google/cloud/resourcemanager/testing/LocalResourceManagerHelper.java

@@ -27,6 +27,7 @@
 import com.google.api.services.cloudresourcemanager.model.SetIamPolicyRequest;
 import com.google.api.services.cloudresourcemanager.model.TestIamPermissionsRequest;
 import com.google.api.services.cloudresourcemanager.model.TestIamPermissionsResponse;
+import com.google.cloud.NoCredentials;
 import com.google.cloud.resourcemanager.ResourceManagerOptions;
 import com.google.common.base.Joiner;
 import com.google.common.base.Objects;
@@ -685,7 +686,7 @@ public ResourceManagerOptions options() {
   public ResourceManagerOptions getOptions() {
     return ResourceManagerOptions.newBuilder()
         .setHost("http://localhost:" + port)
-        .setNoCredentials()
+        .setCredentials(NoCredentials.getInstance())
         .build();
   }