fix for TIKA-3329 contributed by Thamme Gowda

tika-translate/src/main/java/org/apache/tika/language/translate/RTGTranslator.java

@@ -0,0 +1,142 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.tika.language.translate;
+
+import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
+import org.apache.cxf.jaxrs.client.WebClient;
+import org.apache.tika.exception.TikaException;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+
+
+/**
+ * <p>This translator is designed to work with a TCP-IP available
+ * RTG translation server, specifically the
+ * <a href="https://isi-nlp.github.io/rtg/#_rtg_serve">
+ * REST-based RTG server</a>.</p>
+ * To get Docker image:
+ *   https://hub.docker.com/repository/docker/tgowda/rtg-model <br/>
+ * <pre>
+ * {code
+ * # without GPU
+ *   docker run --rm -i -p 6060:6060 tgowda/rtg-model:500toEng-v1
+ * # Or, with GPU device 0
+ *   docker run --rm -i -p 6060:6060 --gpus '"device=0"' tgowda/rtg-model:500toEng-v1
+ * }
+ * </pre>
+ *
+ * <p>If you were to interact with the server via curl a request
+ * would look as follows</p>
+ *
+ * <pre>
+ * {code
+ * curl --data "source=Comment allez-vous?" \
+ *      --data "source=Bonne journée" \
+ *      http://localhost:6060/translate
+ * }
+ * </pre>
+ *
+ * RTG requires input to be pre-formatted into sentences, one per line,
+ * so this translation implementation takes care of that.
+ */
+public class RTGTranslator extends AbstractTranslator {
+
+    public static final String RTG_TRANSLATE_URL_BASE = "http://localhost:6060";
+    public static final String RTG_PROPS = "translator.rtg.properties";
+    private static final Logger LOG = LoggerFactory.getLogger(RTGTranslator.class);
+    private WebClient client;
+    private boolean isAvailable = false;
+
+    public RTGTranslator() {
+        String rtgBaseUrl = RTG_TRANSLATE_URL_BASE;
+        Properties config = new Properties();
+        try (InputStream stream = getClass().getClassLoader().getResourceAsStream(RTG_PROPS)){
+            if (stream != null){
+                config.load(stream);
+            }
+            rtgBaseUrl = config.getProperty("rtg.base.url", rtgBaseUrl);
+        } catch (IOException e) {
+            LOG.warn(e.getMessage(), e);
+        }
+        LOG.info("RTG base URL: " + rtgBaseUrl);
+        List<Object> providers = new ArrayList<>();
+        providers.add(new JacksonJsonProvider());
+        try {
+            this.client = WebClient.create(rtgBaseUrl, providers);
+            this.isAvailable = client.head().getStatus() == 200;
+        } catch (Exception e){
+            LOG.warn(e.getMessage(), e);
+            isAvailable = false;
+        }
+
+    }
+    @Override
+    public String translate(String text, String sourceLanguage, String targetLanguage)
+            throws TikaException, IOException {
+        return this.translate(text);
+    }
+
+    @Override
+    public String translate(String text, String targetLanguage)
+            throws TikaException, IOException {
+        return this.translate(text);
+    }
+
+    public String translate(String text) throws TikaException, IOException {
+        if (!this.isAvailable) {
+            return text;
+        }
+        Map<String, List<Object>> input = new HashMap<>();
+        input.put("source", Arrays.asList(text.split("(?<=(?<![A-Z])\\. )|\\n")));
+        Response response = client.path("translate")
+                .type(MediaType.APPLICATION_JSON)
+                .accept(MediaType.APPLICATION_JSON)
+                .post(input);
+        try (InputStreamReader reader = new InputStreamReader(
+                (InputStream) response.getEntity())) {
+            JSONParser parser = new JSONParser();
+            JSONObject obj = (JSONObject) parser.parse(reader);
+            List<String> sentences = (List<String>) obj.get("translation");
+            String output = String.join("\n", sentences);
+            return output;
+        } catch (ParseException e){
+            throw new IOException(e.getMessage(), e);
+        }
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return this.isAvailable;
+    }
+}

tika-translate/src/main/resources/META-INF/services/org.apache.tika.language.translate.Translator

@@ -18,3 +18,4 @@ org.apache.tika.language.translate.GoogleTranslator
 org.apache.tika.language.translate.Lingo24Translator
 org.apache.tika.language.translate.CachedTranslator
 org.apache.tika.language.translate.JoshuaNetworkTranslator
+org.apache.tika.language.translate.RTGTranslator

tika-translate/src/test/java/org/apache/tika/language/translate/RTGTranslatorTest.java

@@ -0,0 +1,62 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.tika.language.translate;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+
+/**
+ * Test harness for the {@link RTGTranslator}.
+ * 
+ */
+public class RTGTranslatorTest {
+
+	private RTGTranslator translator;
+
+
+	@Before
+	public void setUp() {
+		translator = new RTGTranslator();
+	}
+
+	@Test
+	public void testSimpleTranslate() {
+		String source = "hola señor";
+		String expected = "hello sir";
+
+		String result = null;
+		if (translator.isAvailable()) {
+			try {
+				result = translator.translate(source);
+				assertNotNull(result);
+				assertEquals("Result: [" + result
+						+ "]: not equal to expected: [" + expected + "]",
+						expected, result.toLowerCase());
+			} catch (Exception e) {
+				e.printStackTrace();
+				fail(e.getMessage());
+			}
+		}
+	}
+
+}