com.webcrawler.manager.impl.DownloadManagerImpl.java Source code

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Here is the source code for com.webcrawler.manager.impl.DownloadManagerImpl.java

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package com.webcrawler.manager.impl;

import com.webcrawler.manager.DownloadManager;
import com.webcrawler.manager.StorageManager;
import com.webcrawler.manager.UIManager;
import com.webcrawler.model.ImageDTO;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import javax.swing.SwingWorker;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 *
 * @author jose
 */
@Service("downloadManager")
public class DownloadManagerImpl implements DownloadManager, PropertyChangeListener {

    @Autowired
    private StorageManager storageManager;

    private String folderLocation;
    private List<ImageDTO> images;
    private UIManager ui;
    private ImageDownloaderTask task;

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        if (evt.getPropertyName().equals("progress")) {
            ui.setProgressBarValue((Integer) evt.getNewValue());
        }

    }

    @Override
    public void processDownload(String folderLocation, List<ImageDTO> images, UIManager ui) throws Exception {

        if (StringUtils.isBlank(folderLocation)) {
            throw new IllegalArgumentException("set download folder first");
        }

        if (ui == null) {
            System.out.println("UI is null, assign a UI first");
            throw new IllegalArgumentException("UI is null, assign a UI first");
        }

        if (images == null || images.isEmpty()) {
            throw new IllegalArgumentException("No Images Found!");
        }

        //check if folder exists
        File path = new File(folderLocation);
        if (!path.exists() || !path.isDirectory()) {
            throw new IllegalArgumentException("Folder location does not exist!");
        }

        this.folderLocation = folderLocation;
        this.images = images;
        this.ui = ui;

        task = new ImageDownloaderTask();
        task.addPropertyChangeListener(this);

        task.execute();

    }

    private class ImageDownloaderTask extends SwingWorker<Void, Integer> {

        private static final int BUFFER_SIZE = 4096;

        @Override
        protected Void doInBackground() throws Exception {

            System.out.println("Calling doInBackground...");

            InputStream is = null;
            FileOutputStream fos = null;
            byte[] buffer = null;

            try {

                imagetraverse: for (ImageDTO dto : images) {
                    System.out.println("Retrieving file " + dto.getUrlAddress());

                    try {
                        is = storageManager.downloadImagesFromRemote(dto.getUrlAddress());
                    } catch (IOException ioe) {
                        System.out.println("Cannot download file with url " + dto.getUrlAddress());
                        System.out.println("Skipping...");
                        ioe.printStackTrace();
                        break imagetraverse;
                    }
                    ui.setUIFileInfo(dto.getFileName(), storageManager.getContentLength());

                    try {
                        fos = new FileOutputStream(folderLocation + File.separator + dto.getFileName());
                        buffer = new byte[BUFFER_SIZE];
                        int bytesRead = -1;
                        int totalBytesRead = 0;
                        int percentCompleted = 0;

                        while ((bytesRead = is.read(buffer)) != -1) {

                            fos.write(buffer, 0, bytesRead);
                            totalBytesRead += bytesRead;
                            percentCompleted = (int) (totalBytesRead * 100 / storageManager.getContentLength());

                            publish(percentCompleted);
                        }

                    } catch (IOException ie) {
                        ie.printStackTrace();
                        System.out.println("Error with the file " + dto.getFileName() + " skipping this file....");
                        break imagetraverse;
                    } finally {

                        fos.close();
                        storageManager.disconnect();
                    }

                }
            } catch (IOException ex) {

                ex.printStackTrace();
                ui.showErrorMessageDialog("Error downloading image: " + ex.getMessage(), "Error");

                publish(0);
                cancel(true);
                throw ex;
            } finally {

                try {
                    is.close();
                    fos.close();
                } catch (IOException disregard) {
                }

            }

            return null;
        }

        @Override
        protected void done() {

            if (isCancelled()) {

                ui.showErrorMessageDialog("Download Failed!", "Error");
            } else {

                ui.showMessageDialog("Images have been downloaded successfully!", "Success!");
            }

            ui.enableSearching();
        }

        @Override
        protected void process(List<Integer> chunks) {
            for (Integer chunk : chunks) {
                ui.setProgressBarValue(chunk);
            }
        }
    }
}