org.opencastproject.dictionary.hunspell.DictionaryServiceImpl.java Source code

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Here is the source code for org.opencastproject.dictionary.hunspell.DictionaryServiceImpl.java

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/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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.opencastproject.dictionary.hunspell;

import static org.opencastproject.util.ReadinessIndicator.ARTIFACT;
import org.opencastproject.util.ReadinessIndicator;
import org.osgi.framework.BundleContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Dictionary;
import java.util.Hashtable;
import java.util.LinkedList;
import java.io.UnsupportedEncodingException;

import java.io.OutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import org.apache.commons.lang.StringUtils;

import org.opencastproject.dictionary.api.DictionaryService;
import org.opencastproject.metadata.mpeg7.Textual;
import org.opencastproject.metadata.mpeg7.TextualImpl;

/**
 * This dictionary implementation is a dummy implementation which which will
 * just let the whole text pass through without any kind of filtering.
 */
public class DictionaryServiceImpl implements DictionaryService {

    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(DictionaryServiceImpl.class);

    public static final String HUNSPELL_BINARY_CONFIG_KEY = "org.opencastproject.dictionary.hunspell.binary";

    public static final String HUNSPELL_COMMAND_CONFIG_KEY = "org.opencastproject.dictionary.hunspell.command";

    /* The hunspell binary to execute */
    private String binary = "hunspell";

    /* The regular command line options for filtering */
    private String command = " -i utf-8 -d de_DE,en_GB,en_US -G";

    public void setBinary(String b) {
        binary = b;
    }

    public String getBinary() {
        return binary;
    }

    public void setCommand(String c) {
        command = c;
    }

    public String getCommand() {
        return command;
    }

    /**
     * OSGi callback on component activation.
     *
     * @param  ctx  the bundle context
     */
    void activate(BundleContext ctx) throws UnsupportedEncodingException {
        Dictionary<String, String> properties = new Hashtable<String, String>();
        properties.put(ARTIFACT, "dictionary");
        ctx.registerService(ReadinessIndicator.class.getName(), new ReadinessIndicator(), properties);

        /* Get hunspell binary from config file */
        String binary = (String) ctx.getProperty(HUNSPELL_BINARY_CONFIG_KEY);
        if (binary != null) {
            /* Fix special characters */
            binary = new String(binary.getBytes("ISO-8859-1"), "UTF-8");
            logger.info("Setting hunspell binary to '{}'", binary);
            this.binary = binary;
        }

        /* Get hunspell command line options from config file */
        String command = (String) ctx.getProperty(HUNSPELL_COMMAND_CONFIG_KEY);
        if (command != null) {
            /* Fix special characters */
            command = new String(command.getBytes("ISO-8859-1"), "UTF-8");
            logger.info("Setting hunspell command line options to '{}'", command);
            this.command = command;
        }
    }

    /**
     * Run hunspell with text as input.
     **/
    public LinkedList<String> runHunspell(String text) throws Throwable {

        // create a new list of arguments for our process
        String commandLine = binary + ' ' + command;
        String[] commandList = commandLine.split("\\s+");

        InputStream stdout = null;
        InputStream stderr = null;
        OutputStream stdin = null;
        Process p = null;
        BufferedReader bufr = null;
        LinkedList<String> words = new LinkedList<String>();

        logger.info("Executing hunspell command '{}'", StringUtils.join(commandList, " "));
        p = new ProcessBuilder(commandList).start();
        stderr = p.getErrorStream();
        stdout = p.getInputStream();
        stdin = p.getOutputStream();

        /* Pipe text through hunspell for filtering */
        stdin.write(text.getBytes("UTF-8"));
        stdin.flush();
        stdin.close();

        /* Get output of hunspell */
        String line;
        bufr = new BufferedReader(new InputStreamReader(stdout, "UTF-8"));
        while ((line = bufr.readLine()) != null) {
            words.add(line);
        }
        bufr.close();

        /* Get error messages */
        bufr = new BufferedReader(new InputStreamReader(stderr));
        while ((line = bufr.readLine()) != null) {
            logger.warn(line);
        }
        bufr.close();

        if (p.waitFor() != 0) {
            logger.error("Hunspell reported an error (Missing dictionaries?)");
            throw new IllegalStateException("Hunspell returned error code");
        }

        return words;
    }

    /**
     * Filter the text according to the rules defined by the dictionary
     * implementation used. This implementation will just let the whole text pass
     * through.
     *
     * @return filtered text
     **/
    @Override
    public Textual cleanUpText(String text) {

        LinkedList<String> words = null;

        try {
            words = runHunspell(text);
        } catch (Throwable t) {
            logger.error("Error executing hunspell");
            logger.error(t.getMessage(), t);
            return null;
        }

        String result = StringUtils.join(words, " ");
        if ("".equals(result)) {
            return null;
        }
        return new TextualImpl(result);
    }

}