downloadsetting.java

Java写的下载文件程序

/*DownloadSetting.java*/

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import java.net.*;

class DownloadSetting extends JDialog implements ActionListener,
                                                 WindowListener

{
 //定义私有成员对象 
  private JButton okButton=null;
  private JButton cancelButton=null;
  private JButton searchButton=null;
  private JLabel urlLabel=null;
  private JLabel saveLabel=null;
  private JLabel priorityLabel=null;
  private JLabel threadsLabel=null;
  private JTextField urlText=null;
  private JTextField saveText=null;
  private JComboBox priorityComboBox=null;
  private JComboBox threadsComboBox=null;
  private Vector dataVector=null;

  //构造函数
  public  DownloadSetting(JFrame parent)
  {
   super(parent,"无限下载任务设置",true);
   Container pane =getContentPane();  //取得对话框的内部容器
   pane.setLayout(null);              //屏蔽掉默认的版面管理器

   //建立标签
   urlLabel=new JLabel("网络路径",JLabel.CENTER);
   saveLabel=new JLabel("保存为",JLabel.CENTER);
   priorityLabel=new JLabel("优先权",JLabel.CENTER);
   threadsLabel=new JLabel("分片数",JLabel.CENTER);

   //建立命令按钮
   okButton= new JButton("确定(O)");
   okButton.setMnemonic('O');
   cancelButton= new JButton("取消(C)");
   cancelButton.setMnemonic('C');
   searchButton=new JButton(new ImageIcon("save.jpg"));
   okButton.addActionListener(this);
   cancelButton.addActionListener(this);
   searchButton.addActionListener(this);

   //建立输入文本框
   urlText= new JTextField(20);
   saveText=new JTextField(20);

   //建立复合文本框并初始化数据项
   Vector  number=new Vector(10);
   for (int i=0;i<10;i++)
     number.addElement(new Integer(i+1).toString());
   priorityComboBox=new JComboBox(number);
   threadsComboBox=new JComboBox(number);
   priorityComboBox.setSelectedIndex(4);
   threadsComboBox.setSelectedIndex(4);

   //将各个成员对象添加到容器中
   pane.add(urlLabel);
   pane.add(saveLabel);
   pane.add(priorityLabel);
   pane.add(threadsLabel);
   pane.add(urlText);
   pane.add(saveText);
   pane.add(priorityComboBox);
   pane.add(threadsComboBox);
   pane.add(okButton);
   pane.add(cancelButton);
   pane.add(searchButton);
  
   //设置各个成员对象的边界位置和外观大小
   urlLabel.setBounds(5,5,60,30);
   saveLabel.setBounds(5,40,60,30);
   priorityLabel.setBounds(5,80,60,30);
   threadsLabel.setBounds(200,80,60,30);
   urlText.setBounds(70,10,300,30);
   saveText.setBounds(70,50,265,30);
   priorityComboBox.setBounds(70,85,100,30);
   threadsComboBox.setBounds(270,85,100,30);
   searchButton.setBounds(340,50,30,30);
   okButton.setBounds(100,130,80,30);
   cancelButton.setBounds(200,130,80,30);
   pack();
   setBounds(100,100,380,190);
   setVisible(false);

   //通过inner class方式添加WindowAdapter事件处理类
   addWindowListener(this);
   /*new WindowAdapter()
    {
     public void windowClosing(WindowEvent e)
      {
        setVisible(false);
      }
    });*/
  }//结束构造函数DownloadSetting()

  /*以下部分是公共成员函数*/

  //设置工作方式:1为添加任务方式,2为显示任务信息方式,detail为显示信息
  public void setMode(int mode,Vector detail)
  {
   if (mode==2)
   { 
    okButton.setEnabled(false);
    searchButton.setEnabled(false);
    urlText.setEnabled(false);
    saveText.setEnabled(false);
    priorityComboBox.setEnabled(false);
    threadsComboBox.setEnabled(false);
    urlText.setText(detail.elementAt(0).toString());
    saveText.setText(detail.elementAt(1).toString());
    for(int i=0;i<priorityComboBox.getItemCount();i++)
    {
      String tempString1,tempString2;
      tempString1=priorityComboBox.getItemAt(i).toString();
      tempString2=detail.elementAt(2).toString();
      if(tempString1.equals(tempString2))
        priorityComboBox.setSelectedIndex(i);
      tempString1=threadsComboBox.getItemAt(i).toString();
      tempString2=detail.elementAt(3).toString();
      if(tempString1.equals(tempString2))
        threadsComboBox.setSelectedIndex(i);
    }
   }
   if(mode==1)
   {
    okButton.setEnabled(true);
    searchButton.setEnabled(true);
    urlText.setEnabled(true);
    saveText.setEnabled(true);
    priorityComboBox.setEnabled(true);
    threadsComboBox.setEnabled(true);
    urlText.setText("");
    saveText.setText("");
    priorityComboBox.setSelectedIndex(4);
    threadsComboBox.setSelectedIndex(4);
    urlText.requestFocus();
   }
   setVisible(true);
  }//结束公共成员函数setMode()

  //取得任务数据
  public Vector getDataVector()
  { return dataVector; }

  /*以下部分是对各个接口的实现*/

  //实现ActionListener接口
  public void actionPerformed(ActionEvent e)
  {
   if (e.getSource()==okButton)
   {
    try
    {
     URL url=new URL(urlText.getText());
     //判断输入的信息是否有效,若无效则抛出异常
     if((url.getProtocol()==null) || (url.getHost()==null))
       throw new MalformedURLException();
     if(!url.getProtocol().equalsIgnoreCase("HTTP"))
       throw new MalformedURLException();
     if((url.getHost().length()<1)||(url.getProtocol().length()<1))
       throw new MalformedURLException();
     //如果输入的保存文件路径不完整,则补充完整
     String fileString=saveText.getText();
     if((fileString.endsWith("\\")) || (fileString==null) ||
       (fileString.equals("")))
     {
      String tempString=urlText.getText();
      int indexInt=tempString.lastIndexOf('/');
      fileString=fileString+tempString.substring(indexInt+1);
     }
     File tempFile=new File(fileString);
     String parentString=tempFile.getParent();
     if((parentString!=null)&&(!parentString.equals("")))
     {
      File parentFile=new File(parentString);
      if(!parentFile.exists()) //若目录不存在,则建立新目录
        if(!parentFile.mkdirs()) throw new IOException();
     }                         //无法建立目录是抛出IO异常
     dataVector=new Vector(); //取得输入的信息,存入成员变量中
     dataVector.addElement("运行");
     dataVector.addElement(url.toString());
     dataVector.addElement(fileString);
     dataVector.addElement("0");
     String tempString;
     tempString=priorityComboBox.getSelectedItem().toString();
     dataVector.addElement(tempString);
     tempString=threadsComboBox.getSelectedItem().toString();
     dataVector.addElement(tempString);
     setVisible(false);
    }
    catch(MalformedURLException urlexception)
    {
     JOptionPane.showMessageDialog(null,"输入有错误,请修改后重新提交"
     +"\n程序目前只能支持HTTP协议","错误",JOptionPane.ERROR_MESSAGE);
    }
    catch(NullPointerException nullpoint)
    {
     JOptionPane.showMessageDialog(null,"输入有错误,文件名不能为空",
     "错误",JOptionPane.ERROR_MESSAGE);
    }
    catch(IOException ioe)
    {
     JOptionPane.showMessageDialog(null,"发生意外I/O错误,可能是无法"+
     "建立相应文件目录","错误", JOptionPane.ERROR_MESSAGE);
    }
   }
   if (e.getSource()==cancelButton)
   {
    dataVector=null;
    setVisible(false);
   }
   if (e.getSource()==searchButton)
   {
    String tempString=System.getProperty("user.dir");
    JFileChooser fileChooser=new JFileChooser(tempString);
    fileChooser.setApproveButtonText("确定");
    fileChooser.setDialogTitle("选择下载文件保存路径");
    int result=fileChooser.showOpenDialog(this.getParent());
    if(result==JFileChooser.APPROVE_OPTION)
      saveText.setText(fileChooser.getSelectedFile().getPath());
   }
  }//结束接口函数actionPerformed

  //实现 WindowListener接口
  public void windowClosing(WindowEvent e)
  {
    setVisible(false);
  }
  public void windowOpened(WindowEvent e){}
  public void windowClosed(WindowEvent e){}
  public void windowActivated(WindowEvent e){}
  public void windowDeactivated(WindowEvent e){}
  public void windowIconified(WindowEvent e){}
  public void windowDeiconified(WindowEvent e){}


}//结束类DownloadSetting