Remove Serializable from AuthCredentials, ServiceFactory and ServiceRpcFactory and set factories on ServiceOptions

Author: aozarov

README.md

@@ -61,14 +61,13 @@ Here is a code snippet showing a simple usage example from within Compute/App En
 
 ```java
 import com.google.gcloud.datastore.Datastore;
-import com.google.gcloud.datastore.DatastoreFactory;
 import com.google.gcloud.datastore.DatastoreOptions;
 import com.google.gcloud.datastore.DateTime;
 import com.google.gcloud.datastore.Entity;
 import com.google.gcloud.datastore.Key;
 import com.google.gcloud.datastore.KeyFactory;
 
-Datastore datastore = DatastoreFactory.instance().get(DatastoreOptions.getDefaultInstance());
+Datastore datastore = DatastoreOptions.getDefaultInstance().service();
 KeyFactory keyFactory = datastore.newKeyFactory().kind(KIND);
 Key key = keyFactory.newKey(keyName);
 Entity entity = datastore.get(key);
@@ -106,14 +105,13 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import com.google.gcloud.storage.Blob;
 import com.google.gcloud.storage.BlobId;
 import com.google.gcloud.storage.Storage;
-import com.google.gcloud.storage.StorageFactory;
 import com.google.gcloud.storage.StorageOptions;
 
 import java.nio.ByteBuffer;
 import java.nio.channels.WritableByteChannel;
 
 StorageOptions options = StorageOptions.builder().projectId("project").build();
-Storage storage = StorageFactory.instance().get(options);
+Storage storage = options.service();
 BlobId blobId = BlobId.of("bucket", "blob_name");
 Blob blob = Blob.load(storage, blobId);
 if (blob == null) {

TESTING.md

@@ -18,7 +18,7 @@ You can test against a temporary local datastore by following these steps:
       .projectId(PROJECT_ID)
       .host("http://localhost:8080")
       .build();
-  Datastore localDatastore = DatastoreFactory.instance().get(options);
+  Datastore localDatastore = options.service();
   ```
 3. Run your tests.
 
@@ -35,7 +35,7 @@ You can test against a remote datastore emulator as well.  To do this, set the `
       .projectId(PROJECT_ID)
       .host("http://<hostname of machine>:<port>")
       .build();
-  Datastore localDatastore = DatastoreFactory.instance().get(options);
+  Datastore localDatastore = options.service();
   ```
 
 Note that the remote datastore must be running before your tests are run.
@@ -52,7 +52,7 @@ Currently, there isn't an emulator for Google Cloud Storage, so an alternative i
 Here is an example that uses the `RemoteGcsHelper` to create a bucket.
   ```java
   RemoteGcsHelper gcsHelper = RemoteGcsHelper.create(PROJECT_ID, "/path/to/my/JSON/key.json");
-  Storage storage = StorageFactory.instance().get(gcsHelper.options());
+  Storage storage = gcsHelper.options().service();
   String bucket = RemoteGcsHelper.generateBucketName();
   storage.create(BucketInfo.of(bucket));
   ```

gcloud-java-core/src/main/java/com/google/gcloud/AuthCredentials.java

@@ -31,8 +31,6 @@
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.ObjectInputStream;
-import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.security.GeneralSecurityException;
 import java.security.PrivateKey;
@@ -42,35 +40,91 @@
 /**
  * Credentials for accessing Google Cloud services.
  */
-public abstract class AuthCredentials implements Serializable {
-
-  private static final long serialVersionUID = 236297804453464604L;
+public abstract class AuthCredentials implements Restorable<AuthCredentials> {
 
   private static class AppEngineAuthCredentials extends AuthCredentials {
 
-    private static final long serialVersionUID = 7931300552744202954L;
-
     private static final AuthCredentials INSTANCE = new AppEngineAuthCredentials();
+    private static final AppEngineAuthCredentialsState STATE =
+        new AppEngineAuthCredentialsState();
+
+    private static class AppEngineAuthCredentialsState
+        implements RestorableState<AuthCredentials>, Serializable {
+
+      private static final long serialVersionUID = 3558563960848658928L;
+
+      @Override
+      public AuthCredentials restore() {
+        return INSTANCE;
+      }
+
+      @Override
+      public int hashCode() {
+        return getClass().getName().hashCode();
+      }
+
+      @Override
+      public boolean equals(Object obj) {
+        return obj instanceof AppEngineAuthCredentialsState;
+      }
+    }
 
     @Override
     protected HttpRequestInitializer httpRequestInitializer(HttpTransport transport,
         Set<String> scopes) {
       return new AppIdentityCredential(scopes);
     }
 
-    private Object readResolve() throws ObjectStreamException {
-      return INSTANCE;
+    @Override
+    public RestorableState<AuthCredentials> capture() {
+      return STATE;
     }
   }
 
   public static class ServiceAccountAuthCredentials extends AuthCredentials {
 
-    private static final long serialVersionUID = 8007708734318445901L;
     private final String account;
     private final PrivateKey privateKey;
 
     private static final AuthCredentials NO_CREDENTIALS = new ServiceAccountAuthCredentials();
 
+    private static class ServiceAccountAuthCredentialsState
+        implements RestorableState<AuthCredentials>, Serializable {
+
+      private static final long serialVersionUID = -7302180782414633639L;
+
+      private final String account;
+      private final PrivateKey privateKey;
+
+      private ServiceAccountAuthCredentialsState(String account, PrivateKey privateKey) {
+        this.account = account;
+        this.privateKey = privateKey;
+      }
+
+      @Override
+      public AuthCredentials restore() {
+        if (account == null && privateKey == null) {
+          return NO_CREDENTIALS;
+        }
+        return new ServiceAccountAuthCredentials(account, privateKey);
+      }
+
+      @Override
+      public int hashCode() {
+        return Objects.hash(account, privateKey);
+      }
+
+      @Override
+      public boolean equals(Object obj) {
+        if (!(obj instanceof ServiceAccountAuthCredentialsState)) {
+          return false;
+        }
+        ServiceAccountAuthCredentialsState other = (ServiceAccountAuthCredentialsState) obj;
+        return Objects.equals(account, other.account)
+            && Objects.equals(privateKey, other.privateKey);
+      }
+    }
+
     ServiceAccountAuthCredentials(String account, PrivateKey privateKey) {
       this.account = checkNotNull(account);
       this.privateKey = checkNotNull(privateKey);
@@ -104,59 +158,94 @@ public PrivateKey privateKey() {
     }
 
     @Override
-    public int hashCode() {
-      return Objects.hash(account, privateKey);
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-      if (!(obj instanceof ServiceAccountAuthCredentials)) {
-        return false;
-      }
-      ServiceAccountAuthCredentials other = (ServiceAccountAuthCredentials) obj;
-      return Objects.equals(account, other.account)
-          && Objects.equals(privateKey, other.privateKey);
+    public RestorableState<AuthCredentials> capture() {
+      return new ServiceAccountAuthCredentialsState(account, privateKey);
     }
   }
 
   private static class ComputeEngineAuthCredentials extends AuthCredentials {
 
-    private static final long serialVersionUID = -5217355402127260144L;
+    private ComputeCredential computeCredential;
 
-    private transient ComputeCredential computeCredential;
+    private static final ComputeEngineAuthCredentialsState STATE =
+        new ComputeEngineAuthCredentialsState();
 
-    ComputeEngineAuthCredentials() throws IOException, GeneralSecurityException {
-      computeCredential = getComputeCredential();
-    }
+    private static class ComputeEngineAuthCredentialsState
+        implements RestorableState<AuthCredentials>, Serializable {
+
+      private static final long serialVersionUID = -6168594072854417404L;
+
+      @Override
+      public AuthCredentials restore() {
+        try {
+          return new ComputeEngineAuthCredentials();
+        } catch (IOException | GeneralSecurityException e) {
+          throw new IllegalStateException(
+              "Could not restore " + ComputeEngineAuthCredentials.class.getSimpleName(), e);
+        }
+      }
+
+      @Override
+      public int hashCode() {
+        return getClass().getName().hashCode();
+      }
 
-    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
-      in.defaultReadObject();
-      try {
-        computeCredential = getComputeCredential();
-      } catch (GeneralSecurityException e) {
-        throw new IOException(e);
+      @Override
+      public boolean equals(Object obj) {
+        return obj instanceof ComputeEngineAuthCredentialsState;
       }
     }
 
+    ComputeEngineAuthCredentials() throws IOException, GeneralSecurityException {
+      computeCredential = getComputeCredential();
+    }
+
     @Override
     protected HttpRequestInitializer httpRequestInitializer(HttpTransport transport,
         Set<String> scopes) {
       return computeCredential;
     }
+
+    @Override
+    public RestorableState<AuthCredentials> capture() {
+      return STATE;
+    }
   }
 
   private static class ApplicationDefaultAuthCredentials extends AuthCredentials {
 
-    private static final long serialVersionUID = -8306873864136099893L;
+    private GoogleCredentials googleCredentials;
 
-    private transient GoogleCredentials googleCredentials;
+    private static final ApplicationDefaultAuthCredentialsState STATE =
+        new ApplicationDefaultAuthCredentialsState();
 
-    ApplicationDefaultAuthCredentials() throws IOException {
-      googleCredentials = GoogleCredentials.getApplicationDefault();
+    private static class ApplicationDefaultAuthCredentialsState
+        implements RestorableState<AuthCredentials>, Serializable {
+
+      private static final long serialVersionUID = -8839085552021212257L;
+
+      @Override
+      public AuthCredentials restore() {
+        try {
+          return new ApplicationDefaultAuthCredentials();
+        } catch (IOException e) {
+          throw new IllegalStateException(
+              "Could not restore " + ApplicationDefaultAuthCredentials.class.getSimpleName(), e);
+        }
+      }
+
+      @Override
+      public int hashCode() {
+        return getClass().getName().hashCode();
+      }
+
+      @Override
+      public boolean equals(Object obj) {
+        return obj instanceof ApplicationDefaultAuthCredentialsState;
+      }
     }
 
-    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
-      in.defaultReadObject();
+    ApplicationDefaultAuthCredentials() throws IOException {
       googleCredentials = GoogleCredentials.getApplicationDefault();
     }
 
@@ -165,6 +254,11 @@ protected HttpRequestInitializer httpRequestInitializer(HttpTransport transport,
         Set<String> scopes) {
       return new HttpCredentialsAdapter(googleCredentials);
     }
+
+    @Override
+    public RestorableState<AuthCredentials> capture() {
+      return STATE;
+    }
   }
 
   protected abstract HttpRequestInitializer httpRequestInitializer(HttpTransport transport,

gcloud-java-core/src/main/java/com/google/gcloud/BaseService.java

@@ -16,7 +16,7 @@
 
 package com.google.gcloud;
 
-public abstract class BaseService<OptionsT extends ServiceOptions<?, OptionsT>>
+public abstract class BaseService<OptionsT extends ServiceOptions<?, ?, OptionsT>>
     implements Service<OptionsT> {
 
   private final OptionsT options;

gcloud-java-core/src/main/java/com/google/gcloud/Restorable.java

@@ -0,0 +1,15 @@
+package com.google.gcloud;
+
+/**
+ * Implementation of this interface can persist their state and restore from it.
+ */
+public interface Restorable<T extends Restorable<T>> {
+
+  /**
+   * Capture the state of this object.
+   *
+   * @return a {@link RestorableState} instance that contains the state for this object and can
+   *     restore it afterwards.
+   */
+  RestorableState<T> capture();
+}

gcloud-java-core/src/main/java/com/google/gcloud/RestorableState.java

@@ -23,7 +23,7 @@
  * Implementations of this class must implement {@link java.io.Serializable} to ensure that the
  * state of a the object can be correctly serialized.
  */
-public interface RestorableState<T> {
+public interface RestorableState<T extends Restorable<T>> {
 
   /**
    * Returns an object whose internal state reflects the one saved in the invocation object.

gcloud-java-core/src/main/java/com/google/gcloud/Service.java

@@ -16,6 +16,6 @@
 
 package com.google.gcloud;
 
-public interface Service<OptionsT extends ServiceOptions<?, OptionsT>> {
+public interface Service<OptionsT extends ServiceOptions<?, ?, OptionsT>> {
   OptionsT options();
 }

gcloud-java-core/src/main/java/com/google/gcloud/ServiceFactory.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2015 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.gcloud;
+
+/**
+ * A base interface for all service factories.
+ *
+ * Implementation must provide a public no-arg constructor.
+ * Loading of a factory implementation is done via {@link java.util.ServiceLoader}.
+ */
+public interface ServiceFactory<ServiceT extends Service, ServiceOptionsT extends ServiceOptions> {
+
+  ServiceT create(ServiceOptionsT serviceOptions);
+}