Question

我想创建一个复制文件的swing工作器，并在进度条中显示进度。虽然我复制了粘贴我在博客中找到的代码，但是除了process（）函数之外，所有工作都很正常 - 我不记得显示给你的链接，我收到了编译错误。这是我的代码：

    class Copy extends SwingWorker<Void, Void>
           {
             File src,dest;
             InputStream in;
             OutputStream out;
             JProgressBar bar;
              public Copy(File source,File dst)
              {
                 src=source;
                 dest=dst;
                 //bar=Br;
                 progressBar.setValue(0);
              }

              public Copy(MouseAdapter mouseAdapter) {
                // TODO Auto-generated constructor stub
            }

            protected Void doInBackground() throws Exception
              {
                System.out.print("Started\n");
                InputStream input = null;
                OutputStream output = null;
                try {
                    input = new FileInputStream(src);
                    output = new FileOutputStream(dest);
                    byte[] buf = new byte[1024];
                    int bytesRead;
                    while ((bytesRead = input.read(buf)) > 0) {
                        output.write(buf, 0, bytesRead);
                    }
                } finally {
                    input.close();
                    output.close();
                }
                progressBar.setVisible(true);
                return null;
              }


    //Here I get the error:
    @Override //Description Resource    Path    Location    Type
    //The method process() of type Main.Copy must override or implement a supertype method

                  protected Void process()
                  {
                      long expectedBytes = src.length(); // This is the numbe

r of bytes we expected to copy..
                  byte[] buffer = new byte[1024];
                  int length;
                  long totalBytesCopied = 0; // This will track the total number of bytes we've copied

                  try {
                    while ((length = in.read(buffer)) > 0){
                          out.write(buffer, 0, length);
                          totalBytesCopied += length;
                          int progress = (int)Math.round(((double)totalBytesCopied / (double)expectedBytes) * 100);
                          System.out.print(progress);
                          progressBar.setValue(progress);
                      }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                //  return progress;
              }

              protected void done()
              {
                  System.out.print("Complete\n");
              }

           }   
        }

我无法理解我做错了什么，所以会得到一点帮助。还有什么区别Void

例如protected Void doInBackground（）

和无效

例如protected void done（）

我目前在Eclipse工作，这两个在编辑器中有不同的颜色，所以它们之间存在差异。

Swing Worker不会开始复制文件

0 个答案: