downloadaction.java

该系统是一个基于p2p的即时聊天系统

/*
 * @(#) DownloadAction.java
 * Copyright 2004 HWStudio. All rights reserved.
 */
package hws.item.smart.action.share.download;
//导入核心Java类库
import java.io.File;
import java.io.IOException;
import java.awt.event.ActionEvent;
import java.net.MalformedURLException;
import java.util.Vector;
import javax.swing.JOptionPane;
import javax.swing.JFileChooser;
//导入自定义Java类库
import hws.item.smart.Smart;
import hws.item.smart.misc.XMLConfig;
import hws.item.smart.misc.StringShop;
import hws.item.smart.panel.function.chat.ViewPanel;
import hws.item.smart.panel.function.share.DownloadPanel;
import hws.item.smart.action.BaseAction;
import hws.item.smart.utility.chat.FriendsInfo;
//导入第三方Java类库
import org.jdom.Element;
import org.jdom.Document;
import org.jdom.output.XMLOutputter;
import org.apache.xmlrpc.XmlRpc;
import org.apache.xmlrpc.XmlRpcClient;
import org.apache.xmlrpc.XmlRpcRequest;
import org.apache.xmlrpc.XmlRpcException;
/**
 * 下载选中的文件
 *
 * @version 0.1 2005-08-30
 * @author Hwerz
 */
public class DownloadAction extends BaseAction {
    /*------------------------------------------------------------------------*
     *                                属性定义                                *
     *------------------------------------------------------------------------*/
    /**
     * 该类自身的一个静态引用
     */
    private static DownloadAction action;
    /*------------------------------------------------------------------------*
     *                                构造函数                                *
     *------------------------------------------------------------------------*/
    /**
     * 构造函数为私有，这样在整个运行过程中该类就只能有一个实例
     */
    private DownloadAction() {
        super("下载");
        setHintInfo("下载选中的文件");
        setEnabled(false);
    }
    /*------------------------------------------------------------------------*
     *                                公共方法                                *
     *------------------------------------------------------------------------*/
    /**
     * 对该类提供的一个全局访问点，用来实例化该对象
     *
     * @return 该类唯一的一个实例
     */
    public static DownloadAction getInstance() {
        if (action == null) {
            action = new DownloadAction();
        }
        return action;
    }
    /*------------------------------------------------------------------------*
     *                                私有方法                                *
     *------------------------------------------------------------------------*/
    /**
     * 下载选择的文件到指定的目录下
     *
     * @param dir 指定的目录
     */
    private void download(String dir) {
        try {
            XmlRpc.setDriver("org.apache.xerces.parsers.SAXParser");
            XmlRpcClient client = new XmlRpcClient(genURL());
            client.execute(genRequest(dir));
        } catch (ClassNotFoundException e) {
            JOptionPane.showMessageDialog(Smart.getInstance(),
                "系统找不到类库“org.apache.xerces.parsers.SAXParser”！",
                StringShop.HINT_TITLE, JOptionPane.INFORMATION_MESSAGE);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (XmlRpcException e) {
            e.printStackTrace();
        } catch (IOException e) {
            JOptionPane.showMessageDialog(Smart.getInstance(),
                "好友不在线，文件下载失败！", StringShop.HINT_TITLE,
                JOptionPane.INFORMATION_MESSAGE);
        }
    }
    /**
     * 生成请求URL
     *
     * @return 生成的请求URL
     */
    private String genURL() {
        StringBuffer url = new StringBuffer();
        url.append("http://");
        String friendID = DownloadPanel.getInstance().getSelectedFriendID();
        url.append(FriendsInfo.getFriendIP(friendID));
        url.append(":");
        int delta = Integer.parseInt(friendID);
        url.append(XMLConfig.getRequestPort() + delta);
        url.append("/");
        return url.toString();
    }
    /**
     * 生成XML-RPC请求消息
     *
     * @return 生成的XML-RPC请求消息
     * @param dir 指定的目录
     */
    private XmlRpcRequest genRequest(String dir) {
        //请求方法
        StringBuffer method = new StringBuffer();
        method.append(XMLConfig.getRequestClass());
        method.append(".");
        method.append(XMLConfig.getRequestMethod());
        //请求参数
        Vector params = new Vector();
        XMLOutputter outputter = new XMLOutputter();
        params.addElement(outputter.outputString(genDocument(dir)));
        return new XmlRpcRequest(method.toString(), params);
    }
    /**
     * 生成XML文档
     *
     * @return 生成的XML文档
     * @param dir 指定的目录
     */
    private Document genDocument(String dir) {
        Element request = new Element("Request");
        Element r = new Element("Requester");
        r.setAttribute("id", ViewPanel.getInstance().getUserID());
        r.setAttribute("dir", dir);
        r.setAttribute("file", DownloadPanel.getInstance().getSelectedFile());
        request.addContent(r);
        return new Document(request);
    }
    /*------------------------------------------------------------------------*
     *                                覆盖方法                                *
     *------------------------------------------------------------------------*/
    /**
     * 覆盖超类Action的方法
     *
     * @param event ActionEvent对象
     */
    public void actionPerformed(ActionEvent event) {
        boolean flag = true;
        do {
            JFileChooser chooser = new JFileChooser();
            chooser.setDialogTitle("选择文件保存的目录");
            chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            int option = chooser.showSaveDialog(Smart.getInstance());
            if (option == JFileChooser.APPROVE_OPTION) {
                File file = chooser.getSelectedFile();
                if (file.exists() && file.isDirectory()) {
                    download(file.getAbsolutePath());
                    setEnabled(false);
                    flag = false;
                } else {
                    int option2 = JOptionPane.showConfirmDialog(
                        Smart.getInstance(), "您选择的目录不合法，要继续吗？",
                        StringShop.HINT_TITLE, JOptionPane.YES_NO_OPTION,
                        JOptionPane.QUESTION_MESSAGE);
                    if (option2 == JOptionPane.NO_OPTION) {
                        flag = false;
                    }
                }
            } else {
                flag = false;
            }
        } while (flag);
    }
}