varioustests.swingworkertests.SearchForWordWorker.java Source code

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Here is the source code for varioustests.swingworkertests.SearchForWordWorker.java

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package varioustests.swingworkertests;

//package com.javacreed.examples.swing.worker.part3;//http://www.javacreed.com/swing-worker-example/

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JTextArea;
import javax.swing.SwingWorker;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.SuffixFileFilter;
import org.apache.commons.io.filefilter.TrueFileFilter;
//import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang3.StringUtils;

/**
 * Searches the text files under the given directory and counts the number of instances a given word is found
 * in these file.
 * 
 * @author Albert Attard
 */
public class SearchForWordWorker extends SwingWorker<Integer, String> {

    private static void failIfInterrupted() throws InterruptedException {
        if (Thread.currentThread().isInterrupted()) {
            throw new InterruptedException("Interrupted while searching files");
        }
    }

    /** The word that is searched */
    private final String word;

    /**
     * The directory under which the search occurs. All text files found under the given directory are searched.
     */
    private final File directory;

    /** The text area where messages are written. */
    private final JTextArea messagesTextArea;

    /**
     * Creates an instance of the worker
     * 
     * @param word
     *          The word to search
     * @param directory
     *          the directory under which the search will occur. All text files found under the given directory
     *          are searched
     * @param messagesTextArea
     *          The text area where messages are written
     */
    public SearchForWordWorker(final String word, final File directory, final JTextArea messagesTextArea) {
        this.word = word;
        this.directory = directory;
        this.messagesTextArea = messagesTextArea;
    }

    @Override
    protected Integer doInBackground() throws Exception {
        // The number of instances the word is found
        int matches = 0;

        /*
         * List all text files under the given directory using the Apache IO library. This process cannot be
         * interrupted (stopped through cancellation). That is why we are checking right after the process whether
         * it was interrupted or not.
         */
        publish("Listing all text files under the directory: " + directory);
        final List<File> textFiles = new ArrayList<>(
                FileUtils.listFiles(directory, new SuffixFileFilter(".txt"), TrueFileFilter.TRUE));
        SearchForWordWorker.failIfInterrupted();
        publish("Found " + textFiles.size() + " text files under the directory: " + directory);

        for (int i = 0, size = textFiles.size(); i < size; i++) {
            /*
             * In order to respond to the cancellations, we need to check whether this thread (the worker thread)
             * was interrupted or not. If the thread was interrupted, then we simply throw an InterruptedException
             * to indicate that the worker thread was cancelled.
             */
            SearchForWordWorker.failIfInterrupted();

            // Update the status and indicate which file is being searched. 
            final File file = textFiles.get(i);
            publish("Searching file: " + file);

            /*
             * Read the file content into a string, and count the matches using the Apache common IO and Lang
             * libraries respectively.
             */
            final String text = FileUtils.readFileToString(file);
            matches += StringUtils.countMatches(text, word);

            // Update the progress
            setProgress((i + 1) * 100 / size);
        }

        // Return the number of matches found
        return matches;
    }

    @Override
    protected void process(final List<String> chunks) {
        // Updates the messages text area
        for (final String string : chunks) {
            messagesTextArea.append(string);
            messagesTextArea.append("\n");
        }
    }
}