открыть и сохранить кнопку в java SWT

Question

Я выполняю некоторые задания, и я не знаю, как начать делать кнопку сохранения и открытия. Я использую SWT, и мое приложение собирается читать и писать в XML-файле. Я делаю для этого методы, но теперь проблема заключается в открытии существующего файла и сохранении существующего файла. Если вы можете мне помочь, это будет отлично.

import org.eclipse.swt.widgets.Display; 
import org.eclipse.swt.widgets.FileDialog; 
import org.eclipse.swt.widgets.Shell; 
import org.eclipse.swt.widgets.Label; 
import org.eclipse.swt.widgets.MessageBox; 
import org.eclipse.swt.SWT; 
import org.eclipse.swt.widgets.Text; 
import org.eclipse.swt.widgets.Button; 
import org.eclipse.swt.events.SelectionAdapter; 
import org.eclipse.swt.events.SelectionEvent; 
import org.eclipse.swt.layout.GridData; 
import org.eclipse.swt.widgets.Menu; 
import org.eclipse.swt.widgets.MenuItem; 
import org.eclipse.swt.widgets.Combo; 

import testic.CurrentData; 
import testic.ReadWrite; 


public class Test { 

     // These filter names are displayed to the user in the file dialog. Note that 
     // the inclusion of the actual extension in parentheses is optional, and 
     // doesn't have any effect on which files are displayed. 

     private static final String[] FILTER_NAMES = { 
      "EXtensible Markup Language (*.xml)", 
      "All Files (*.*)"}; 

     // These filter extensions are used to filter which files are displayed. 
     private static final String[] FILTER_EXTS = { "*.xml", "*.*"}; 

    protected Shell shell; 
    private Text text; 
    private static CurrentData currentData = null; 
    static ReadWrite test; 


    /** 
    * Launch the application. 
    * @param args 
    */ 
    public static void main(String[] args) { 
     try { 
      Test window = new Test(); 
      currentData = new CurrentData(); 
      test = new ReadWrite(currentData) ; 
      test.readXML(); 
      window.open(); 

     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    /** 
    * Open the window. 
    */ 
    public void open() { 
     Display display = Display.getDefault(); 
     createContents(); 
     shell.open(); 
     shell.layout(); 
     while (!shell.isDisposed()) { 
      if (!display.readAndDispatch()) { 
       display.sleep(); 
      } 
     } 
    } 


    /** 
    * Create contents of the window. 
    */ 
    protected void createContents() { 
     shell = new Shell(); 
     shell.setSize(450, 300); 
     shell.setText("Test App"); 

     //UNIXUSER 

     Label lblUsername = new Label(shell, SWT.NONE); 
     lblUsername.setBounds(45, 64, 55, 15); 
     lblUsername.setText("Username:"); 

     text = new Text(shell, SWT.BORDER); 
     text.setBounds(179, 61, 91, 21); 
     text.setText(currentData.getUnixUser()); 


     // DISABLE_TRAFFIC_CHECK 

     Label lblStatus = new Label(shell, SWT.NONE); 
     lblStatus.setBounds(45, 111, 118, 15); 
     lblStatusk.setText("Disable traffic check:"); 

     Button btnCheckButton = new Button(shell, SWT.CHECK); 
     btnCheckButton.setSelection(currentData.getDisableTrafficCheck()); 
     btnCheckButton.setBounds(212, 110, 93, 16); 


     // HEALTCHECL_EVERY_TC 

     Label lblActive = new Label(shell, SWT.NONE); 
     lblActive.setBounds(45, 156, 129, 15); 
     lblActive.setText("Health check every TC:"); 

     Menu menu_1 = new Menu(shell); //TODO check if we really need this 
     shell.setMenu(menu_1); 

     String[] items = { "None", "True", "False" }; 
     Combo combo = new Combo(shell, SWT.NONE); 
     combo.setBounds(179, 156, 91, 23); 
     combo.setItems(items); 
     String hC = currentData.getHealthCheckEveryTC(); 
     if(hC.equalsIgnoreCase("None")){ 
      combo.select(0); 
     } else if (hC.equalsIgnoreCase("True")){ 
      combo.select(1); 
     } else { 
      combo.select(2); 
     } 



     Menu menu = new Menu(shell, SWT.BAR); 
     shell.setMenuBar(menu); 

     /** Create file menu*/ 

     MenuItem mntmFile = new MenuItem(menu, SWT.CASCADE); 
     mntmFile.setText("File"); 

     Menu menu_2 = new Menu(mntmFile); 
     mntmFile.setMenu(menu_2); 

     /** New Window*/ 

     MenuItem mntmNew = new MenuItem(menu_2, SWT.NONE); 
     mntmNew.setText("New"); 
     mntmNew.addSelectionListener(new SelectionAdapter() { 
      @Override 
      public void widgetSelected(SelectionEvent e) { 
       Test windowNew = new Test(); 
       windowNew.open();     
      } 
     }); 

     /**Open window*/ 

     final Text fileName = new Text(shell, SWT.BORDER); 
     GridData data = new GridData(GridData.FILL_HORIZONTAL); 
     data.horizontalSpan = 4; 
     fileName.setLayoutData(data); 

     MenuItem mntmOpen = new MenuItem(menu_2, SWT.NONE); 
     mntmOpen.setText("Open"); 
     mntmOpen.addSelectionListener(new SelectionAdapter() { 
      public void widgetSelected(SelectionEvent event) { 
      // User has selected to open a single file 
      FileDialog dlg = new FileDialog(shell, SWT.OPEN); 
      dlg.setFilterNames(FILTER_NAMES); 
      dlg.setFilterExtensions(FILTER_EXTS); 
      String fn = dlg.open(); 
      if (fn != null) { 
       fileName.setText(fn); 
      } 
      } 
     }); 

     MenuItem mntmSave = new MenuItem(menu_2, SWT.NONE); 


     mntmSave.setText("Save"); 


     MenuItem mntmSaveAs = new MenuItem(menu_2, SWT.NONE); 
     mntmSaveAs.setText("Save As"); 
     mntmSaveAs.addSelectionListener(new SelectionAdapter() { 
      public void widgetSelected(SelectionEvent event) { 
       // User has selected to save a file 
       test.createXML(); 
       FileDialog dlg = new FileDialog(shell, SWT.SAVE); 
       dlg.setFilterNames(FILTER_NAMES); 
       dlg.setFilterExtensions(FILTER_EXTS); 
       dlg.setFilterPath("c:\\"); // Windows path 
       String fn = dlg.open(); 
       if (fn != null) { 
       fileName.setText(fn); 
       } 
      } 
      }); 

     MenuItem mntmExit = new MenuItem(menu_2, SWT.NONE); 
     mntmExit.addSelectionListener(new SelectionAdapter() { 
      @Override 
      public void widgetSelected(SelectionEvent e) { 
       MessageBox messageBox = new MessageBox(shell, SWT.ICON_QUESTION 
         | SWT.YES | SWT.NO); 
        messageBox.setMessage("Do you really want to exit?"); 
        messageBox.setText("Exiting Application"); 
        int response = messageBox.open(); 
        if (response == SWT.YES) 
         System.exit(0); 
      } 
     }); 
     mntmExit.setText("Exit"); 

    } 

    protected static void event(String string, Object object) { 
     // TODO Auto-generated method stub 

    } 
} 

Answer 1

open метод FileDialog возвращает абсолютный путь (первый) выбранный файл или null, если диалог был отменен. Вы должны прочитать/записать в этот файл. Пример:

FileDialog dlg = ... 
String filename = dlg.open(); 
if (filename != null) { 
    File file = new File(filename); 
    readXML(file); 
} 

Возможно, это SWT snippet полезно?