Add Translate.listSupportedLanguages method and tests

gcloud-java-translate/src/main/java/com/google/cloud/translate/Option.java

@@ -0,0 +1,72 @@
+/*
+ * 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.translate;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.cloud.translate.spi.TranslateRpc;
+import com.google.common.base.MoreObjects;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+/**
+ * Base class for Translate operation option.
+ */
+abstract class Option implements Serializable {
+
+  private static final long serialVersionUID = 8546712558603322394L;
+
+  private final TranslateRpc.Option rpcOption;
+  private final Object value;
+
+  Option(TranslateRpc.Option rpcOption, Object value) {
+    this.rpcOption = checkNotNull(rpcOption);
+    this.value = value;
+  }
+
+  TranslateRpc.Option rpcOption() {
+    return rpcOption;
+  }
+
+  Object value() {
+    return value;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (!(obj instanceof Option)) {
+      return false;
+    }
+    Option other = (Option) obj;
+    return Objects.equals(rpcOption, other.rpcOption)
+        && Objects.equals(value, other.value);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(rpcOption, value);
+  }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+        .add("name", rpcOption.value())
+        .add("value", value)
+        .toString();
+  }
+}

gcloud-java-translate/src/main/java/com/google/cloud/translate/Translate.java

@@ -17,11 +17,57 @@
 package com.google.cloud.translate;
 
 import com.google.cloud.Service;
+import com.google.cloud.translate.spi.TranslateRpc;
+
+import java.util.List;
 
 /**
  * An interface for Google Translate.
  *
  * @see <a href="https://cloud.google.com/translate/docs">Google Translate</a>
  */
 public interface Translate extends Service<TranslateOptions> {
+
+  /**
+   * Class for specifying supported language listing options.
+   */
+  class LanguageListOption extends Option {
+
+    private static final long serialVersionUID = 1982978040516658597L;
+
+    private LanguageListOption(TranslateRpc.Option rpcOption, String value) {
+      super(rpcOption, value);
+    }
+
+    /**
+     * Returns an option for setting the target language. If this option is not provided, the value
+     * returned by {@link TranslateOptions#targetLanguage()} is used. When provided, the returned
+     * {@link Language#name()} will be in the language specified by the {@code targetLanguage} code.
+     *
+     * @param targetLanguage the target language code
+     */
+    public static LanguageListOption targetLanguage(String targetLanguage) {
+      return new LanguageListOption(TranslateRpc.Option.TARGET_LANGUAGE, targetLanguage);
+    }
+  }
+
+  /**
+   * Returns the list of languages supported by Google Translate. If
+   * {@link LanguageListOption#targetLanguage(String)} is provided, {@link Language#name()} values
+   * are localized according to the provided target language. If no such option is passed,
+   * {@link Language#name()} values are localized according to
+   * {@link TranslateOptions#targetLanguage()}.
+   *
+   * <p>Example of listing supported languages, localized according to
+   * {@link TranslateOptions#targetLanguage()}:
+   * <pre> {@code
+   * List<Language> languages = translate.listSupportedLanguages();
+   * }</pre>
+   * Or according to another target language:
+   * <pre> {@code
+   * List<Language> languages = translate.listSupportedLanguages(
+   *     LanguageListOption.targetLanguage("es"));
+   * }</pre>
+   */
+  List<Language> listSupportedLanguages(LanguageListOption... options);
 }

gcloud-java-translate/src/main/java/com/google/cloud/translate/TranslateImpl.java

@@ -0,0 +1,64 @@
+/*
+ * 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.translate;
+
+import static com.google.cloud.RetryHelper.runWithRetries;
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.api.services.translate.model.LanguagesResource;
+import com.google.cloud.BaseService;
+import com.google.cloud.RetryHelper.RetryHelperException;
+import com.google.cloud.translate.spi.TranslateRpc;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Callable;
+
+final class TranslateImpl extends BaseService<TranslateOptions> implements Translate {
+
+  private final TranslateRpc translateRpc;
+
+  TranslateImpl(TranslateOptions options) {
+    super(options);
+    translateRpc = options.rpc();
+  }
+
+  @Override
+  public List<Language> listSupportedLanguages(final LanguageListOption... options) {
+    try {
+      return Lists.transform(runWithRetries(new Callable<List<LanguagesResource>>() {
+        @Override
+        public List<LanguagesResource> call() {
+          return translateRpc.listSupportedLanguages(optionMap(options));
+        }
+      }, options().retryParams(), EXCEPTION_HANDLER, options().clock()), Language.FROM_PB_FUNCTION);
+    } catch (RetryHelperException e) {
+      throw TranslateException.translateAndThrow(e);
+    }
+  }
+
+  private Map<TranslateRpc.Option, ?> optionMap(Option... options) {
+    Map<TranslateRpc.Option, Object> optionMap = Maps.newEnumMap(TranslateRpc.Option.class);
+    for (Option option : options) {
+      Object prev = optionMap.put(option.rpcOption(), option.value());
+      checkArgument(prev == null, "Duplicate option %s", option);
+    }
+    return optionMap;
+  }
+}

gcloud-java-translate/src/main/java/com/google/cloud/translate/TranslateOptions.java

@@ -43,9 +43,7 @@ public static class DefaultTranslateFactory implements TranslateFactory {
 
     @Override
     public Translate create(TranslateOptions options) {
-      return null;
-      // todo(mziccard) uncomment as soon as TranslateImpl is implemented
-      // return new TranslateImpl(options);
+      return new TranslateImpl(options);
     }
   }
 
@@ -174,7 +172,13 @@ public int hashCode() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof TranslateOptions && baseEquals((TranslateOptions) obj);
+    if (!(obj instanceof TranslateOptions)) {
+      return false;
+    }
+    TranslateOptions options = (TranslateOptions) obj;
+    return baseEquals(options)
+        && apiKey.equals(options.apiKey)
+        && targetLanguage.equals(options.targetLanguage);
   }
 
   /**

gcloud-java-translate/src/test/java/com/google/cloud/translate/OptionTest.java

@@ -0,0 +1,62 @@
+/*
+ * 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.translate;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNull;
+
+import com.google.cloud.translate.spi.TranslateRpc;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class OptionTest {
+
+  private static final TranslateRpc.Option RPC_OPTION = TranslateRpc.Option.SOURCE_LANGUAGE;
+  private static final String VALUE = "some value";
+  private static final String OTHER_VALUE = "another value";
+  private static final Option OPTION = new Option(RPC_OPTION, VALUE) {};
+  private static final Option OPTION_EQUALS = new Option(RPC_OPTION, VALUE) {};
+  private static final Option OPTION_NOT_EQUALS = new Option(RPC_OPTION, OTHER_VALUE) {};
+
+  @Rule
+  public ExpectedException thrown = ExpectedException.none();
+
+  @Test
+  public void testEquals() {
+    assertEquals(OPTION, OPTION_EQUALS);
+    assertNotEquals(OPTION, OPTION_NOT_EQUALS);
+  }
+
+  @Test
+  public void testHashCode() {
+    assertEquals(OPTION.hashCode(), OPTION_EQUALS.hashCode());
+  }
+
+  @Test
+  public void testConstructor() {
+    assertEquals(RPC_OPTION, OPTION.rpcOption());
+    assertEquals(VALUE, OPTION.value());
+    Option option = new Option(RPC_OPTION, null) {};
+    assertEquals(RPC_OPTION, option.rpcOption());
+    assertNull(option.value());
+    thrown.expect(NullPointerException.class);
+    new Option(null, VALUE) {};
+  }
+}