求java http下载代码

如题

解决方案 »

  1.   

    JAVA提供了一些包专门用来下载，也有一些工具也可以实现这一功能，去网上查查
      

  2.   

    http://calmness.javaeye.com/blog/220075
      

  3.   

    response.setContentType("application/x-msdownload"); // 下载显示的文件名
    String fileName = (String) request.getParameter("fileName");
    // 硬盘存放路径
    String filePath = (String) request.getParameter("filePath"); response.addHeader("Content-Disposition", "attachment;filename=" + fileName); OutputStream outp = null;
    FileInputStream fis = null;
    boolean isCancelDownload = false; try {
    outp = response.getOutputStream();
    fis = new FileInputStream(filePath); byte[] b = new byte[1024];
    int i = 0; while ((i = fis.read(b)) > 0) {
    try {
    outp.write(b, 0, i);
    } catch (IOException e) {
    isCancelDownload = true;
    break;
    }
    } if (!isCancelDownload) {
    outp.flush();
    }
    out.clear();
    out = pageContext.pushBody();
    } finally {
    if (fis != null) {
    fis.close();
    fis = null;
    }
    if (outp != null) {
    if (!isCancelDownload) {
    outp.close();
    }
    outp = null;
    }
    }
      

  4.   

    可以参考一下如下实例：package DownLoad;import java.awt.BorderLayout;import java.awt.FileDialog;import java.awt.Frame;import java.awt.GridBagLayout;import java.awt.GridLayout;import java.awt.Image;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.BufferedWriter;import java.io.FileWriter;import java.io.IOException;import java.io.PrintWriter;import javax.swing.*;public class Dinterface extends JFrame { JPanel p1 = new JPanel(); JPanel p2 = new JPanel(); JPanel p3 = new JPanel(); JPanel p4 = new JPanel(); JPanel p5 = new JPanel();  String urlPath; String savePath; int count; //设置滚动条 JProgressBar Js= new JProgressBar(0,100);  JTextArea JT = new JTextArea(15, 20); JLabel J1 = new JLabel("下载地址："); JTextField JTF1 = new JTextField(20);    JLabel J2 = new JLabel("保存位置："); JTextField JTF2 = new JTextField(14); JButton JB1 = new JButton("另存为"); JButton JB = new JButton("开始下载"); JScrollPane JS = new JScrollPane(JT);  JSpinner jsp=new JSpinner(new SpinnerNumberModel(5,0,20,1)); JLabel L = new JLabel("线程数"); public Dinterface() {  super("多线程下载器");  JTF1.setText("http://image.stareastnet.com/2006/09/06/20060906160102g1700.mp3");  JB.addActionListener(new ActionListener() {   public void actionPerformed(ActionEvent e) {    ButtonAction(e);   }  });  JB1.addActionListener(new ActionListener() {   public void actionPerformed(ActionEvent e) {    ButtonActione(e);   }   });    p4.setLayout(new GridLayout(2,1));      p1.add(JS);  p2.add(J1);  p2.add(JTF1);  p2.add(Js);      p2.add(L);  p2.add(jsp);    p2.add(JB1);    p3.add(J2);  p3.add(JTF2);  p3.add(JB);  p4.add(p2);  p4.add(p3);      Js.setStringPainted(true);  setLayout(new BorderLayout());  add(p1, BorderLayout.NORTH);  add(p4, BorderLayout.CENTER);  add(p5, BorderLayout.SOUTH);  setSize(340, 440);  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  this.setResizable(false);  setVisible(true); } private void ButtonAction(ActionEvent e) {  if (e.getSource() == JB) {   //主线程       urlPath=JTF1.getText();       savePath=JTF2.getText();       count=(Integer)(jsp.getValue());       if(urlPath.equals("")){        JT.setText("请输入完整的下载地址");       }else if(savePath.equals("")){        JT.setText("请输入完整的保存地址");       }       else {           try {     BusDown busdown=new BusDown(urlPath,savePath,JT,count,Js);     System.out.println(count);     Thread t=new Thread(busdown);     t.start();    } catch (IOException e1) {     // TODO Auto-generated catch block     e1.printStackTrace();    }          JT.append("\n"+"寻找服务器资源..."+"\n");             JT.append("\n"+"主线程已启动..."+"\n");                       }       }  } private void ButtonActione(ActionEvent e) {  if(e.getSource()==JB1){        urlPath=JTF1.getText();        savePath=JTF2.getText();   Frame f = new Frame("另存为");   FileDialog fd = new FileDialog(f, "另存为", FileDialog.SAVE);   int index=urlPath.lastIndexOf(".");   String ends=urlPath.substring(index, urlPath.length());   fd.setFile("*"+ends);   fd.setVisible(true);   try {    String savepath = fd.getDirectory();    String savename = fd.getFile();    if (savename != null) {     JTF2.setText(savepath+savename);    }   } catch (Exception esave) {   }  }   } public static void main(String[] args) {  new Dinterface(); }}