一个简单的java窗体下载小程序(完整代码)

监听事件的listener包：
其中，ui包：
MainWin.java
package下载.ui;
public class MainWin {
public static void main(String[] args) {
DownloadWin win = new DownloadWin("下载");
}
* <p>文件保存目录
*/
private void downFile(String httpAddress, String fileDir) {
SplitString httpSplit = new SplitString();
fileName = httpSplit.split(httpAddress,"/");//根据“/”分解
private InputStream itStream;
private DataInputStream in;
private FileOutputStream otStream;
private DataOutputStream out;
public DownloadListener(JTextField httpLine, JTextField savePath,
Box boxV2 = Box.createHorizontalBox();
Box boxV3 = Box.createHorizontalBox();
Box boxV4 = Box.createHorizontalBox();
Box boxV5 = Box.createHorizontalBox();
*
* @param accordingString
* @return返回“/”之后最后一个字符串
*/
public String split(String splitString,String accordingString) {
//httpAddress.endsWith("/");
//如果a/c/则返回的字符串是c
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import .URL;
import .URLConnection;
lineLabel = new JLabel("访问地址：");
httpLine = new JTextField();
saveLabel = new JLabel("保存路径：");
savePath = new JTextField();
btnDownload = new JButton("下载");
infoLabel = new JLabel();
/**
*监听器
*/
DownloadListener listener = new DownloadListener(httpLine,savePath,infoLabel);//将需要改变显示状态的控件传递过去处理
btnDownload.addActionListener(listener);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
private void init() {
Box baseBox = Box.createVerticalBox();
Box boxV1 = Box.createHorizontalBox();
}
DownloadWin.java
package下载.ui;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
package下载.listener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.DataInputStream;
import java.io.DataOutputStream;
private JTextField httpLine;
private JTextField savePath;
private JButton btnDownload;
private JLabel lineLabel;
private JLabel saveLabel;
private static JLabel infoLabel;
while((n=itStream.read(b))!=-1){
otStream.flush();
otStream.write(b);
}
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
//otStream.flush();//刷新此输出流并强制写出所有缓冲的输出字节
//String[] str = httpAddress.split("/");
//"unhappy".substring(2) returns "happy"
//"a.s.k"stIndexOf(".") returns 3
//splitstr = str[str.length-1];//获取“/”之后最后一个字符串
import javax.swing.JLabel;
import javax.swing.JTextField;
import下载.listener.DownloadListener;
public class DownloadWin extends JFrame{
/**
*
*/
private static final long serialVersionUID = -7226361346020458023L;
baseBox.add(boxV2);
Box.createVerticalStrut(15);
baseBox.add(boxV3);
Box.createVerticalStrut(15);
baseBox.add(boxV4);
Box.createVerticalStrut(15);
baseBox.add(boxV5);
public DownloadWin(String title) {
init();
setTitle(title);
setSize(400,300);
setLayout(new GridLayout(2, 1, 0, 0));//为美观考虑，第二行没有使用。
setLocationRelativeTo(null);
System.out.println(fileName);
if(""==fileName||null==fileName||""==fileDir||null==fileDir){
System.out.println("网络地址或保存路径不正确");
infoLabel.setText("网络地址或保存路径不正确");
//in.close();
itStream.close();
import javax.swing.JLabel;
import javax.swing.JTextField;
import下载.util.SplitString;
public class DownloadListener implements ActionListener {
private JTextField httpLine, savePath;
//获取链接指向的文件的相关数据
itStream = conn.getInputStream();
//in = new DataInputStream(itStream);//数据输入流
otStream = new FileOutputStream(file);//根据文件创建输出流
//out = new DataOutputStream(otStream);//数据输出流
首先，这只是一个很简单的程序，所以大神请绕道。
心血来潮，用java编写了一个能访问http链接，并能下载文件的窗体小程序。实测能够正确下载17M的压缩包，图片，文档，html等。但是因为程序效率低下，于是没有继续测试更大的压缩文件（问题可能在于保存输入流到缓冲区的数组）。
程序已打包jar可执行文件，并将代码一齐打包到jar中。为方便使用jar，使用word文档对象包装了它，将下面的对象（显示为一个图标）拖到桌面或者其他文件夹，即可得到该程序：
}
else{
System.out.println("下载中...");
infoLabel.setText("下载中...");
try {
url = new URL(httpAddress);//设置链接
conn = url.openConnection();//打开链接
file = new File(fileDir,fileName);