Java 在执行方法之前等待拖放手势

我有一个名为

FileDragDemo

的类，其目的是将一个PDF文件拖放（DnD）到GUI，一旦完成，它将显示被拖放文件的路径。我们将此步骤称为第1步，它目前运行良好！然后，我想将此文件路径保存为字符串变量

StringFile

，并将其传递给另一个类

PdfEasyManager

第2步是运行class

PdfEasyManager

（在上一步完全完成后）并传递

StringFile

变量。这就是我正在努力的地方——我创建了一个名为

CallClass

的方法，我希望在所有步骤1完成后执行该方法（DnD和字符串变量被存储）；换句话说，我希望方法

CallClass

是

FileDragDemo

类中采取的最后一步。当我将

CallClass

作为main方法中的最后一项时，程序在DnD手势之前执行它……换句话说，程序在调用

PdfEasyManager

之前不会等待用户对文件进行DnD。我还尝试更改了

CallClass

的位置，但出现了不同的错误。很抱歉代码中的所有注释，因为我正在尝试不同的东西

下面是Filedragdemo的代码：

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

@SuppressWarnings("serial")
public class FileDragDemo extends JPanel {


public static String StringFile; 
public JList list = new JList();



public FileDragDemo() {
  list.setDragEnabled(true);
  list.setTransferHandler(new FileListTransferHandler(list));

  add(new JScrollPane(list));

}

public static void createAndShowGui() {
  FileDragDemo mainPanel = new FileDragDemo();

  JFrame frame = new JFrame("FileDragDemo");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.getContentPane().add(mainPanel);
  frame.pack();
  frame.setLocationByPlatform(true);
  frame.setVisible(true);


}

public static void CallClass() throws Exception {

   PdfEasyManager PdfEasyManagerObject = new PdfEasyManager ();

      try {

          PdfEasyManagerObject.main(null);

        } catch (IOException e) {
             //TODO Auto-generated catch block
            e.printStackTrace();
        }
}

public static void main(String[] args) throws Exception {


  SwingUtilities.invokeLater(new Runnable() {
     public void run() {
        createAndShowGui();

     }

  }); 
callClass();
}

}

@SuppressWarnings("serial")
class FileListTransferHandler extends TransferHandler {
public JList list;


public static String StringFile;


public FileListTransferHandler(JList list) {
  this.list = list;
}

public int getSourceActions(JComponent c) {
  return COPY_OR_MOVE;
}

public boolean canImport(TransferSupport ts) {
  return ts.isDataFlavorSupported(DataFlavor.javaFileListFlavor);
}

public boolean importData(TransferSupport ts){
  try {
     @SuppressWarnings("rawtypes")

     List data = (List) ts.getTransferable().getTransferData(
           DataFlavor.javaFileListFlavor);
     if (data.size() < 1) {
        return false;
     }// close if

     DefaultListModel listModel = new DefaultListModel();

     for (Object item : data) {

          File file = (File) item;
         //file1 = item;
        listModel.addElement(file);
        System.out.println ("%%%%%%%%%%%file... " + file);
        StringFile = file.toString();
        System.out.println ("%%%%%%%%%%%string... " + StringFile);          
     } // close for
     //String filestring = file.toString();

     list.setModel(listModel);
     return true;


  }// close try  
  catch (UnsupportedFlavorException e) {
     return false;
  } catch (IOException e) {
     return false;
  } 

}
}

import java.io.File;
import java.io.IOException;


public class PdfEasyManager {

public static File file;  

public static void main(String[] args) throws Exception {


    CallEasy();
    CallSearch();

    /* System.out.println ("StringFile is: " + StringFile);
    file = new File (StringFile);*/

    //EasySearch easysearchobject = new EasySearch();
    //System.out.println(easysearchobject.ToText()); //For some reason this needs to be there in order for it to work..?

    /*searchPdftext searchPdftextobject = new searchPdftext();
                try {
                    searchPdftextobject.main(null);
        } catch (Exception e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }*/


 }
public static void CallEasy()throws Exception {
    EasySearch easysearchobject = new EasySearch();
    System.out.println(easysearchobject.ToText()); //For some reason this needs to be there in order for it to work..?
}

public static void CallSearch()throws Exception {
     searchPdftext searchPdftextobject = new searchPdftext();
     try {
         searchPdftextobject.main(null);
     } catch (Exception e1) {
         // TODO Auto-generated catch block
         e1.printStackTrace();
     }
}
}    

---

将StringFile设置为“属性”，并对triger CallClass（）使用属性更改。另外，只定义一次StringFile。将StringFile设置为“属性”，并对triger CallClass（）使用属性更改。也只定义一次StringFile。