fileexchangeview.java

来自「JAVA Servlet2.3外文书籍源码」· Java 代码 · 共 181 行

package firewall.client;

import firewall.common.FileValidator;
import java.io.*;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.filechooser.*;

import java.net.URL;
import java.net.MalformedURLException;

/**
 * Title:        FileExchangeView
 * Description:  Contains the application view/gui elements and setup
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author Andrew Harbourne-Thomas
 * @version 1.0
 */
public class FileExchangeView extends JFrame {

  /** servers address */
  URL hostServlet;

  /** reference to the model */
  FileExchangeModel model = new FileExchangeModel(this);

  /** message area */
  private final JTextArea messages = new JTextArea(5, 20);

  /** JList used to hold list of files */
  final JList fileList = new JList();

  /** File chooser to select file to upload to server */
  final JFileChooser fc = new JFileChooser();

  /** Refresh button */
  JButton refreshButton = new JButton("Refresh Filelist");

  /** Upload button */
  JButton uploadButton = new JButton("Upload File");

  /** Download button */
  JButton downloadButton = new JButton("Download File");

  /** Delete button */
  JButton deleteButton = new JButton("Delete File");

  /** Panel to hold buttons */
  JPanel buttonPanel = new JPanel();

  /** Panel to hold file list and messages */
  JPanel displayPanel = new JPanel();

  /**
   * Constructor prepares and setups up the applications gui
   *
   * @param server Reference to the servers address
   */
  public FileExchangeView(URL server, String name) {
    super(name);

    this.hostServlet = server;

    //create the message window and the filelist
    messages.setMargin(new Insets(5, 5, 5, 5));
    messages.setEditable(false);
    JScrollPane messageScrollPane = new JScrollPane(messages);
    fileList.setSize(50, 100);
    fileList.setEnabled(true);
    fileList
      .setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
    JScrollPane fileListScrollPane = new JScrollPane();
    fileListScrollPane.getViewport().setView(fileList);

    //add listener to the refresh button
    refreshButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        //call refresh method
        model.refreshRequest();
        messages.setText("");
      }
    });

    //add listener to the upload button
    uploadButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        //show a dialog to allow user to select file to send to server
        fc.setDialogTitle("Select file to Upload..........");

        FileExchangeFilter filter =
          new FileExchangeFilter(FileValidator.VALID_EXTENSIONS, "Text files");
        fc.setFileFilter(filter);

        int returnVal = fc.showSaveDialog(FileExchangeView.this);

        //perform users selected choice
        if (returnVal == JFileChooser.APPROVE_OPTION) {
          File file = fc.getSelectedFile();
          messages.append("Uploading: " + file.getName() + "\n");
          model.uploadRequest(file);
        }
        else {
          messages.append("Upload command cancelled by user.\n");
        }
        //refresh list of files after deletion
        model.refreshRequest();
      }
    });

    //add listener to the download button
    downloadButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        model.downloadRequest((String) fileList.getSelectedValue());
      }
    });

    //add listener to the delete button
    deleteButton.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        model.deleteRequest((String) fileList.getSelectedValue());
      }
    });

    //prepare buttons
    buttonPanel.add(refreshButton);
    buttonPanel.add(uploadButton);
    buttonPanel.add(downloadButton);
    buttonPanel.add(deleteButton);

    //set the focus order
    refreshButton.setNextFocusableComponent(uploadButton);
    uploadButton.setNextFocusableComponent(downloadButton);
    downloadButton.setNextFocusableComponent(deleteButton);
    deleteButton.setNextFocusableComponent(refreshButton);

    //finish the gui setup
    displayPanel.setLayout(new GridLayout(1, 2));
    displayPanel.add(fileListScrollPane);
    displayPanel.add(messageScrollPane);

    Container contentPane = getContentPane();
    contentPane.setLayout(new BorderLayout());
    contentPane.add(buttonPanel, BorderLayout.CENTER);
    contentPane.add(displayPanel, BorderLayout.NORTH);

    //setup the filelist
    model.refreshRequest();
  }

  /**
   * Accesses the URL for the server
   *
   * @return URL for the server
   */
  public URL getHostServlet() {
    return hostServlet;
  }

  /**
   * Appends text to our message box
   *
   * @param message - text to be appended
   */
  public void appendMessage(String message) {
    messages.append(message + "\n");
  }

  /**
   *Refreshes the filelist
   *
   * @param files - String array of files
   */
  public void refreshFileList(String[] files) {
    fileList.setListData(files);
  }

}