Add TranslateExample class, update gcloud-java-examples README

gcloud-java-examples/README.md

@@ -168,6 +168,16 @@ To run examples from your command line:
     via the NIO API. It lists gcloud-java-nio as a dependency, and that enables it to interpret
     `gs://` paths.
 
+  * Here's an example run of `TranslateExample`.
+
+    Before running the example, go to the [Google Developers Console][developers-console] to ensure that "Google Translate API" is enabled and that you have a valid API key.
+    ```
+    target/appassembler/bin/TranslateExample <apiKey> languages
+    target/appassembler/bin/TranslateExample <apiKey> detect Hello,\ World!
+    target/appassembler/bin/TranslateExample <apiKey> translate ¡Hola\ Mundo!
+    target/appassembler/bin/TranslateExample <apiKey> es translate Hello,\ World!
+    ```
+
 Troubleshooting
 ---------------
 

gcloud-java-examples/pom.xml

@@ -100,6 +100,10 @@
               <mainClass>com.google.cloud.examples.storage.StorageExample</mainClass>
               <name>StorageExample</name>
             </program>
+            <program>
+              <mainClass>com.google.cloud.examples.translate.TranslateExample</mainClass>
+              <name>TranslateExample</name>
+            </program>
           </programs>
         </configuration>
       </plugin>

gcloud-java-examples/src/main/java/com/google/cloud/examples/translate/TranslateExample.java

@@ -0,0 +1,215 @@
+/*
+ * 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.examples.translate;
+
+import com.google.cloud.translate.Detection;
+import com.google.cloud.translate.Language;
+import com.google.cloud.translate.Translate;
+import com.google.cloud.translate.TranslateOptions;
+import com.google.cloud.translate.Translation;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * An example of using Google Translate.
+ *
+ * <p>This example demonstrates a simple/typical Translate usage.
+ *
+ * <p>See the
+ * <a href="https://github.com/GoogleCloudPlatform/gcloud-java/blob/master/gcloud-java-examples/README.md">
+ * README</a> for compilation instructions. Run this code with
+ * <pre>{@code target/appassembler/bin/TranslateExample
+ *  -Dexec.args="<apiKey> [<targetLanguage>]
+ *  list languages <languageCode>?
+ *  detect <text>+
+ *  translate <text>+"}</pre>
+ *
+ * <p>The first parameter is an optional {@code targetLanguage}. If the target language is not
+ * supplied, {@code en} is used (see {@link TranslateOptions.Builder#targetLanguage(String)}).
+ */
+public class TranslateExample {
+
+  private static final Map<String, TranslateAction> ACTIONS = new HashMap<>();
+
+  private abstract static class TranslateAction<T> {
+
+    abstract void run(Translate translate, T arg) throws Exception;
+
+    abstract T parse(String... args) throws Exception;
+
+    protected String params() {
+      return "";
+    }
+  }
+
+  /**
+   * This class demonstrates how to list supported languages.
+   *
+   * @see <a href="https://cloud.google.com/translate/v2/discovering-supported-languages-with-rest">
+   *     Discovering Supported Languages</a>
+   */
+  private static class ListLanguagesAction extends TranslateAction<Void> {
+    @Override
+    public void run(Translate translate, Void arg) {
+      List<Language> languages = translate.listSupportedLanguages();
+      System.out.println("Supported languages:");
+      for (Language language : languages) {
+        System.out.println(language);
+      }
+    }
+
+    @Override
+    Void parse(String... args) throws Exception {
+      if (args.length == 0) {
+        return null;
+      }
+      throw new IllegalArgumentException("This action takes no arguments.");
+    }
+  }
+
+  /**
+   * This class demonstrates how detect the language of some texts.
+   *
+   * @see <a href="https://cloud.google.com/translate/v2/detecting-language-with-rest">Detecting
+   *     Language</a>
+   */
+  private static class DetectLanguageAction extends TranslateAction<List<String>> {
+    @Override
+    public void run(Translate translate, List<String> texts) {
+      List<Detection> detections = translate.detect(texts);
+      if (texts.size() == 1) {
+        System.out.println("Detected language is:");
+      } else {
+        System.out.println("Detected languages are:");
+      }
+      for (Detection detection : detections) {
+        System.out.println(detection);
+      }
+    }
+
+    @Override
+    List<String> parse(String... args) throws Exception {
+      if (args.length >= 1) {
+        return Arrays.asList(args);
+      } else {
+        throw new IllegalArgumentException("Missing required texts.");
+      }
+    }
+
+    @Override
+    public String params() {
+      return "<text>+";
+    }
+  }
+
+  /**
+   * This class demonstrates how to translate some texts.
+   *
+   * @see <a href="https://cloud.google.com/translate/v2/translating-text-with-rest">Translating
+   *     Text</a>
+   */
+  private static class TranslateTextAction extends TranslateAction<List<String>> {
+    @Override
+    public void run(Translate translate, List<String> texts) {
+      List<Translation> translations = translate.translate(texts);
+      if (texts.size() == 1) {
+        System.out.println("Translation is:");
+      } else {
+        System.out.println("Translations are:");
+      }
+      for (Translation translation : translations) {
+        System.out.println(translation);
+      }
+    }
+
+    @Override
+    List<String> parse(String... args) throws Exception {
+      if (args.length >= 1) {
+        return Arrays.asList(args);
+      } else {
+        throw new IllegalArgumentException("Missing required texts.");
+      }
+    }
+
+    @Override
+    public String params() {
+      return "<text>+";
+    }
+  }
+
+  static {
+    ACTIONS.put("languages", new ListLanguagesAction());
+    ACTIONS.put("detect", new DetectLanguageAction());
+    ACTIONS.put("translate", new TranslateTextAction());
+  }
+
+  private static void printUsage() {
+    StringBuilder actionAndParams = new StringBuilder();
+    for (Map.Entry<String, TranslateAction> entry : ACTIONS.entrySet()) {
+      actionAndParams.append(System.lineSeparator()).append('\t').append(entry.getKey());
+      String param = entry.getValue().params();
+      if (param != null && !param.isEmpty()) {
+        actionAndParams.append(' ').append(param);
+      }
+    }
+    System.out.printf("Usage: %s <apiKey> [<targetLanguage>] operation <args>*%s%n",
+        TranslateExample.class.getSimpleName(), actionAndParams);
+  }
+
+  @SuppressWarnings("unchecked")
+  public static void main(String... args) throws Exception {
+    if (args.length < 2) {
+      System.out.println("Missing required api key and action");
+      printUsage();
+      return;
+    }
+    TranslateOptions.Builder optionsBuilder = TranslateOptions.builder(args[0]);
+    TranslateAction action;
+    String actionName;
+    if (args.length >= 3 && !ACTIONS.containsKey(args[1])) {
+      actionName = args[2];
+      optionsBuilder.targetLanguage(args[1]);
+      args = Arrays.copyOfRange(args, 3, args.length);
+    } else {
+      actionName = args[1];
+      args = Arrays.copyOfRange(args, 2, args.length);
+    }
+    action = ACTIONS.get(actionName);
+    if (action == null) {
+      System.out.println("Unrecognized action.");
+      printUsage();
+      return;
+    }
+    Object arg;
+    try {
+      arg = action.parse(args);
+    } catch (IllegalArgumentException ex) {
+      System.out.printf("Invalid input for action '%s'. %s%n", actionName, ex.getMessage());
+      System.out.printf("Expected: %s%n", action.params());
+      return;
+    } catch (Exception ex) {
+      System.out.println("Failed to parse arguments.");
+      ex.printStackTrace();
+      return;
+    }
+    Translate translate = optionsBuilder.build().service();
+    action.run(translate, arg);
+  }
+}