Erstens muss jeder wissen, dass ich relativ neu in der Java-Codierung bin. Genauer gesagt bin ich völlig neu in der objektorientierten Programmierung.

Zur Frage.

Ich versuche, eine Download-Klasse zu erstellen, die einen Fortschrittsbalken aktualisiert, der den Fortschritt anzeigt. Und evtl. irgendetwas anderes entscheide ich mich, es in Zukunft zu aktualisieren.

Das Problem ist derzeit, dass dies in meinem Kopf nicht funktionieren sollte. Ich kann mit der "main" -Methode alles machen, was ich will, und die GUI reagiert immer noch schnell und schnell. Nach meiner Erfahrung mit der Programmierung in der Vergangenheit ist dies nur möglich, wenn ich die GUI einfädle. Warum ist das?

Ist das in Ordnung, da es funktioniert?

Klasse Main

package atomicElectronics;

import java.io.IOException;

import atomicElectronics.physical.AtomFrame;
import atomicElectronics.utility.Download;

public class Initial {

    static AtomFrame atomLauncher;

    public static void main(String[] args) {

        atomLauncher = new AtomFrame();
        atomLauncher.start();

        System.out.println(Integer.MAX_VALUE);

        Download theDownload = new Download();
        theDownload.fileProgressBar(atomLauncher.progressBar);
        try {
            theDownload.exicute("http://download.videolan.org/pub/videolan/vlc/last/win64/vlc-2.1.3-win64.exe", "C:\\Users\\TrinaryAtom\\AppData\\Roaming");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // TODO Add Download Methods
        // theDownload.updateBarTotal(JProgressBar);
        // theDownload.updateLabelSpeed(String);
        // theDownload.updateLabelTotal(String);
        // theDownload.addFile(File);
        // theDownload.addFiles(Files);
    }

}

Klasse AtomFrame

package atomicElectronics.physical;

import javax.swing.JFrame;
import java.awt.FlowLayout;
import javax.swing.JProgressBar;

public class AtomFrame extends JFrame{

    public JProgressBar progressBar;

    private static final long serialVersionUID = 4010489530693307355L;

    public static void main(String[] args){
        AtomFrame testFrame = new AtomFrame();
        testFrame.start();
    }

    public AtomFrame(){
        initializeComponents();
    }

    public void initializeComponents(){
        this.setSize(400, 400);
        this.setLocationRelativeTo(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("Atom Launcher");
        this.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));

        progressBar = new JProgressBar();
        this.add(progressBar);

        //this.pack();
    }

    public void start() {
        this.setVisible(true);
    }

    public void close() {
        this.dispose();
    }
}

Klasse herunterladen

package atomicElectronics.utility;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.swing.JProgressBar;

public class Download {

    private static final int BUFFER_SIZE = 4096;
    private JProgressBar fileProgressBar;

    public Download() {
    }

    public void fileProgressBar(JProgressBar fileBar) {
        fileProgressBar = fileBar;
    }

    public void exicute(String fileURL, String saveDir) throws IOException  {

        URL url = new URL(fileURL);
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
        int responseCode = httpConn.getResponseCode();

        // always check HTTP response code first
        if (responseCode == HttpURLConnection.HTTP_OK) {
            String fileName = "";
            String disposition = httpConn.getHeaderField("Content-Disposition");
            String contentType = httpConn.getContentType();
            double contentLength = httpConn.getContentLength();

            if (disposition != null) {
                // extracts file name from header field
                int index = disposition.indexOf("filename=");
                if (index > 0) {


          fileName = disposition.substring(index + 9,
                        disposition.length());
            }
        } else {
            // extracts file name from URL
            fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
                    fileURL.length());
        }

        System.out.println("Content-Type = " + contentType);
        System.out.println("Content-Disposition = " + disposition);
        System.out.println("Content-Length = " + contentLength);
        System.out.println("fileName = " + fileName);

        // opens input stream from the HTTP connection
        InputStream inputStream = httpConn.getInputStream();
        String saveFilePath = saveDir + File.separator + fileName;

        // opens an output stream to save into file
        FileOutputStream outputStream = new FileOutputStream(saveFilePath);

        double totalRead = 0;
        int bytesRead = -1;
        byte[] buffer = new byte[BUFFER_SIZE];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
            totalRead += bytesRead;
            System.out.println((totalRead / contentLength) * 100);
            fileProgressBar.setValue((int)((totalRead / contentLength) * 100));
        }

        outputStream.close();
        inputStream.close();

        System.out.println("File downloaded");
    } else {
        System.out.println("No file to download. Server replied HTTP code: " + responseCode);
    }
    httpConn.disconnect();

}

}