download.java

一个用JAVA编写的简单下载器,希望能给初学者带来帮助

package com;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class Download implements ActionListener
{
	JFrame jMain=new JFrame("小楠下载器");
	
	private JLabel label=new JLabel("请输入下载地址：");
	private final JTextField text=new JTextField(15);
	private final JTextArea area=new JTextArea();
	private JButton btn2=new JButton("下载"),
	btn=new JButton("显示信息");
	private JPanel north2=new JPanel()
		,north1=new JPanel();
	
	
	
	public void Downloading()
	{
		jMain.setSize(400,300);
		jMain.setLocation(100, 100);
		north1.add(label);
		north1.add(text);
		jMain.getContentPane().add(north1,"North");
		jMain.getContentPane().add(area,"Center");
		north2.add(btn);
		north2.add(btn2);
		jMain.getContentPane().add(north2,"South");
		btn.addActionListener(this/*new ActionListener(){
			public void actionPerformed(ActionEvent e)
			{
				String str=text.getText();
				try
				{
					URL url=new URL(str);
					URLConnection connection=url.openConnection();
					String line=System.getProperty("line.separator");
					area.append("主机名："+url.getHost());
					area.append(line);
					area.append("授权：："+url.getAuthority());
					area.append(line);
					area.append("文件名："+url.getFile());
					area.append(line);
					area.append("端口号："+url.getDefaultPort());
					area.append(line);
					area.append("Type: "+connection.getContentType());
					area.append(line);
					area.append("长度："+connection.getContentLength());
					
				}
				catch(Exception ee)
				{
					ee.printStackTrace();
				}
			}
		}*/);
		btn2.addActionListener(this/*
									 * new ActionListener() { public void
									 * actionPerformed(ActionEvent e) { String
									 * str=text.getText(); try { URL url=new
									 * URL(str); URLConnection
									 * connection=url.openConnection();
									 * InputStream
									 * ips=connection.getInputStream();
									 * FileOutputStream fos=new
									 * FileOutputStream("D:\\rencai.txt"); int
									 * data; while((data=ips.read())!=-1) {
									 * fos.write(data); } ips.close();
									 * fos.close(); } catch(Exception ee) {
									 * ee.printStackTrace(); } } }
									 */);
		jMain.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		jMain.setVisible(true);
	}

	public static void main(String[] args) {
		Download down = new Download();
		down.Downloading();
	}

	public void actionPerformed(ActionEvent e) {
		if (e.getSource().equals(btn2)) {
			String str = text.getText();
			try {
				URL url = new URL(str);
				URLConnection connection = url.openConnection();
				InputStream ips = connection.getInputStream();
				FileOutputStream fos = new FileOutputStream("D:\\rencai.txt");
				int data;
				while ((data = ips.read()) != -1) {
					fos.write(data);
						}
					ips.close();
					fos.close();
				}
			catch(Exception ee)
				{
					ee.printStackTrace();
				}
		}
		else if(e.getSource().equals(btn))
		{
			String str=text.getText();
			try
			{
				URL url=new URL(str);
				URLConnection connection=url.openConnection();
				String line=System.getProperty("line.separator");
				area.append("主机名："+url.getHost());
				area.append(line);
				area.append("授权：："+url.getAuthority());
				area.append(line);
				area.append("文件名："+url.getFile());
				area.append(line);
				area.append("端口号："+url.getDefaultPort());
				area.append(line);
				area.append("Type: "+connection.getContentType());
				area.append(line);
				area.append("长度："+connection.getContentLength());
				
			}
			catch(Exception ee)
			{
				ee.printStackTrace();
			}
		}
		
	}
}