SWT读写文件，生成新文件
通过FileDialog读写文件

FileDialog fd = new FileDialog(Display.getDefault().getActiveShell(),    SWT.OPEN);  fd.setFilterExtensions(new String[] { "*.java" });  String result = fd.open();  if (result != null && !"".equals(result)) {   File file = new File(result);   try {    BufferedReader br = new BufferedReader(new FileReader(file));    StringBuffer sb = new StringBuffer(1024);    String line = br.readLine();    while (line != null){     sb.append(line);     line = br.readLine();       }    sb.append("");    textArea.setText(sb.toString());    br.close();   } catch (FileNotFoundException e) {    e.printStackTrace();   } catch (IOException e) {    e.printStackTrace();   }  }

FileDialog fd = new FileDialog(Display.getCurrent().getActiveShell(),    SWT.SAVE);  fd.setFilterExtensions(new String[] { "*.java" });  String result = fd.open();  if (result != null && !"".equals(result)) {   try {    BufferedWriter bw = new BufferedWriter(new FileWriter(result));    bw.write(textArea.getText());    bw.flush();    bw.close();   } catch (FileNotFoundException e) {    e.printStackTrace();   } catch (IOException e) {    e.printStackTrace();   }  }