/**
* 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 javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Properties;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.cxf.jaxrs.client.WebClient;
import org.apache.tika.exception.TikaException;
import org.apache.tika.language.translate.Translator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static java.nio.charset.StandardCharsets.UTF_8;
/**
* An implementation of a REST client for the YANDEX <a href="https://tech.yandex.com/translate/">Translate API</a>.
* You can sign up for free access online on the <a href="https://tech.yandex.com/key/form.xml?service=trnsl">API Key form</a>
* and set your Application's User Key in the <code>translator.yandex.properties</code> file.
*/
public class YandexTranslator implements Translator {
private static final Logger LOG = LoggerFactory.getLogger(YandexTranslator.class);
/**
* Yandex Translate API service end-point URL
*/
private static final String YANDEX_TRANSLATE_URL_BASE = "https://translate.yandex.net/api/v1.5/tr.json/translate";
/**
* Default USer-Key, a real User-Key must be provided before the Lingo24 can successfully request translations
*/
private static final String DEFAULT_KEY = "dummy-key";
/**
* Identifies the client of the request, used for authentication
*/
private String apiKey;
/**
* The Yandex Translate API can handle text in <b>plain</b> and/or <b>html</b> format, the default
* format is <b>plain</b>
*/
private String format = "plain";
public YandexTranslator() {
Properties config = new Properties();
try {
config.load(YandexTranslator.class
.getResourceAsStream(
"translator.yandex.properties"));
this.apiKey = config.getProperty("translator.api-key");
this.format = config.getProperty("translator.text.format");
} catch (Exception e) {
LOG.warn("Exception loading Yandex config", e);
}
}
@Override
public String translate(String text, String sourceLanguage,
String targetLanguage) throws TikaException, IOException {
if (!this.isAvailable()) {
return text;
}
WebClient client = WebClient.create(YANDEX_TRANSLATE_URL_BASE);
String langCode;
if (sourceLanguage == null) {
//Translate Service will identify source language
langCode = targetLanguage;
} else {
//Source language is well known
langCode = sourceLanguage + '-' + targetLanguage;
}
//TODO Add support for text over 10k characters
Response response = client.accept(MediaType.APPLICATION_JSON)
.query("key", this.apiKey).query("lang", langCode)
.query("text", text).get();
BufferedReader reader = new BufferedReader(new InputStreamReader(
(InputStream) response.getEntity(), UTF_8));
String line = null;
StringBuffer responseText = new StringBuffer();
while ((line = reader.readLine()) != null) {
responseText.append(line);
}
try {
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonResp = mapper.readTree(responseText.toString());
if (!jsonResp.findValuesAsText("code").isEmpty()) {
String code = jsonResp.findValuesAsText("code").get(0);
if (code.equals("200")) {
return jsonResp.findValue("text").get(0).asText();
} else {
throw new TikaException(jsonResp.findValue("message").get(0).asText());
}
} else {
throw new TikaException("Return message not recognized: " + responseText.toString().substring(0, Math.min(responseText.length(), 100)));
}
} catch (JsonParseException e) {
throw new TikaException("Error requesting translation from '" + sourceLanguage + "' to '" + targetLanguage + "', JSON response from Lingo24 is not well formatted: " + responseText.toString());
}
}
/**
* Get the API Key in use for client authentication
* @return API Key
*/
public String getApiKey() {
return apiKey;
}
/**
* Set the API Key for client authentication
* @param apiKey API Key
*/
public void setApiKey(String apiKey) {
this.apiKey = apiKey;
}
/**
* Retrieve the current text format setting.
* The Yandex Translate API can handle text in <b>plain</b> and/or <b>html</b> format, the default
* format is <b>plain</b>
* @return
*/
public String getFormat() {
return format;
}
/**
* Set the text format to use (plain/html)
* @param format Text format setting, either plain or html
*/
public void setFormat(String format) {
this.format = format;
}
@Override
public String translate(String text, String targetLanguage)
throws TikaException, IOException {
return this.translate(text, null, targetLanguage);
}
@Override
public boolean isAvailable() {
return this.apiKey!=null && !this.apiKey.equals(DEFAULT_KEY);
}
}