code: /*
   *  Copyright 2017 Rodrigo Agerri
  
      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 eus.ixa.ixa.pipe.opinion;
  
  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.StringReader;
  import java.io.UnsupportedEncodingException;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.nio.charset.StandardCharsets;
  import java.util.Properties;
  
  import org.jdom2.JDOMException;
  
  import com.google.common.io.Files;
  
  import ixa.kaflib.KAFDocument;
  
  public class OpinionTaggerServer {
  
    /**
     * Get dynamically the version of ixa-pipe-opinion by looking at the MANIFEST
     * file.
     */
    private final String version = CLI.class.getPackage().getImplementationVersion();
    /**
     * Get the git commit of the ixa-pipe-opinion compiled by looking at the MANIFEST
     * file.
     */
    private final String commit = CLI.class.getPackage().getSpecificationVersion();
    /**
     * The aspect and target model.
     */
    private String targetModel;
    /**
     * The polarity classification model.
     */
    private String polarityModel;
    /**
     * The annotation output format, one of NAF (default) or tabulated.
     */
    //private String outputFormat;
    
    /**
     * Construct a server.
     * @param port the port number
     * @param oteProperties the properties of the target and aspect labeler
     * @param polProperties the polarity classifier properties
     * @throws IOException if io problems
     */
    public OpinionTaggerServer(String port, Properties oteProperties, Properties polProperties) throws IOException {
  
      int portNumber = Integer.parseInt(port);
      targetModel = oteProperties.getProperty("targetModel");
      polarityModel = polProperties.getProperty("polarityModel");
      //outputFormat = oteProperties.getProperty("outputFormat");
      Annotate annotator = new AnnotateAbsa(oteProperties, polProperties);
      String kafToString;
      ServerSocket socketServer = null;
      Socket activeSocket;
      BufferedReader inFromClient;
      BufferedWriter outToClient = null;
  
      try {
        System.out.println("-> Trying to listen port... " + port);
        socketServer = new ServerSocket(portNumber);
        System.out.println("-> Connected and listening to port " + port);
        while (true) {
          try {
            activeSocket = socketServer.accept();
            inFromClient = new BufferedReader(new InputStreamReader(activeSocket.getInputStream(),
                StandardCharsets.UTF_8));
            outToClient = new BufferedWriter(new OutputStreamWriter(activeSocket.getOutputStream(),
                StandardCharsets.UTF_8));
            //get data from client
            String stringFromClient = getClientData(inFromClient);
            // annotate
            assert annotator != null;
            kafToString = getAnnotations(annotator, stringFromClient);
          } catch (JDOMException e) {
            kafToString = "\n-> ERROR: Badly formatted NAF document!!\n";
            sendDataToClient(outToClient, kafToString);
            continue;
          } catch (UnsupportedEncodingException e) {
            kafToString = "\n-> ERROR: UTF-8 not supported!!\n";
            assert outToClient != null;
            sendDataToClient(outToClient, kafToString);
            continue;
          } catch (IOException e) {
            kafToString = "\n -> ERROR: Input data not correct!!\n";
            assert outToClient != null;
            sendDataToClient(outToClient, kafToString);
            continue;
          }
          //send data to server after all exceptions and close the outToClient
          sendDataToClient(outToClient, kafToString);
          //close the resources
          inFromClient.close();
          activeSocket.close();
        } //end of processing block
      } catch (IOException e) {
        e.printStackTrace();
        System.err.println("-> IOException due to failing to create the TCP socket or to wrongly provided model path.");
      } finally {
        System.out.println("closing tcp socket...");
        try {
          assert socketServer != null;
          socketServer.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
    
    /**
     * Read data from the client and output to a String.
     * @param inFromClient the client inputstream
     * @return the string from the client
     */
    private String getClientData(BufferedReader inFromClient) {
      StringBuilder stringFromClient = new StringBuilder();
      try {
        String line;
        while ((line = inFromClient.readLine()) != null) {
          if (line.matches("<ENDOFDOCUMENT>")) {
            break;
          }
          stringFromClient.append(line).append("\n");
          if (line.matches("</NAF>")) {
            break;
          }
        }
      }catch (IOException e) {
        e.printStackTrace();
      }
      return stringFromClient.toString();
    }
    
    /**
     * Send data back to server after annotation.
     * @param outToClient the outputstream to the client
     * @param kafToString the string to be processed
     * @throws IOException if io error
     */
    private void sendDataToClient(BufferedWriter outToClient, String kafToString) throws IOException {
      outToClient.write(kafToString);
      outToClient.close();
    }
    
    /**
     * OTE annotator.
     * 
     * @param annotator
     *          the annotator
     * @param stringFromClient
     *          the string to be annotated
     * @return the annotation result
     * @throws IOException
     *           if io error
     * @throws JDOMException
     *           if xml error
     */
    private String getAnnotations(Annotate annotator, String stringFromClient)
        throws IOException, JDOMException {
      // get a breader from the string coming from the client
      BufferedReader clientReader = new BufferedReader(new StringReader(
          stringFromClient));
      KAFDocument kaf = KAFDocument.createFromStream(clientReader);
      KAFDocument.LinguisticProcessor newLp = kaf.addLinguisticProcessor(
          "opinions", "ixa-pipe-opinion-" + "jar",
          version + "-" + commit);
      newLp.setBeginTimestamp();
      annotator.annotate(kaf);
      newLp.setEndTimestamp();
      // get outputFormat
      String kafToString = annotator.annotateToNAF(kaf);
      /*if (outputFormat.equalsIgnoreCase("tabulated")) {
        kafToString = annotator.annotateToNAF(kaf);
      } else {
        kafToString = annotator.annotateToNAF(kaf);
      }
       */
      return kafToString;
    }
  
  }
  