java - 为什么当我开始此操作时我的框架会卡住[下载]

Question

我制作了一个带有“开始下载”按钮的框架，用于从网站下载 JAR。

问题是每当我点击开始下载按钮时，整个框架就会卡住，直到下载完成，然后就正常了。

我该如何解决这个问题？

这是单击按钮时执行的代码

 private void addToDesktop() throws IOException {

    URL url = new URL("urlremoved");
    URLConnection connection = url.openConnection();
    InputStream inputstream = connection.getInputStream();
    FileSystemView filesys = FileSystemView.getFileSystemView();
    filesys.getHomeDirectory();
    sizeOfClient = connection.getContentLength();
    BufferedOutputStream bufferedoutputstream = new BufferedOutputStream(new FileOutputStream(new File(clientDL.textField1.getText() + "/jarname.jar")));
    byte[] buffer = new byte[2048];
    int length;


    while(( length = inputstream.read(buffer)) > -1)
    {
        down += length;
        bufferedoutputstream.write(buffer, 0 , length);
         String text = clientDL.label1.getText();
        int perc = getPerc();

        if(perc <= 50)
        {
            text +=  getPerc() + "% done";
        }else
        {
            text ="Please wait until the jar is downloading...";
            text = text + (100 - perc) + " % remaining";
        }
    }

    if (down == sizeOfClient) {
        JOptionPane.showMessageDialog(clientDL.frame, "Download successful. It has been placed at : " + clientDL.textField1.getText() + "/jarname.jar", "Success!", JOptionPane.INFORMATION_MESSAGE);
        clientDL.frame.dispose();
        clientDL.frame.setVisible(false);

    }
    bufferedoutputstream.flush();
    bufferedoutputstream.close();
    inputstream.close();
    hideSplashScreen();
}

Answer 1

简短的回答:如果您不希望它卡住，则需要在单独的线程上运行它。

有很多方法可以实现这一点。几乎所有方法都需要您将 addToDestop() 方法提取到可运行的类中。此类可以扩展 Thread 或 SwingWorker 或任何此类性质的内容。

您可以查看以下 SwingWorker 链接。

http://www.oracle.com/technetwork/articles/javase/swingworker-137249.html

下面的伪代码会给你一个想法。

public class Downloader extends SwingWorker<VOID, VOID> {
    private String url;

    public Downloader(String url){
        this.url = url;
    }

    private void addToDesktop(){
        //your code
    }

    @override
    protected void doInBackground(){
        addToDesktop();
    }

    @override
    protected void done(){
        //success
    }
}