想做一个下载图片的程序。

[zlheadof]

当我打开一个网页的时候可以有很多的图图，要是一张一张存的话很麻烦，
现在不用下载软件，想自己做一个程序，而且可以自动改名的，下载到指这的位置。
请各位大侠帮帮我，
先给个思路，
要JAVA哪方面的知识，还有网络哪方面的知识。

[zlheadof]

能说的细点吗？谢谢！

[ddbean]

可以使用jspsmartupload组件来完成下载功能。

[tomcatjava]

使用HtmlParser包试一下！！老外写的！

[abcpl]

jspsmartupload是服务器端组件，不太符合要求哦
楼主要求的事主动下载
你可以使用URL类

[java悠悠]

搂主你要的是这个吧

package httpget;

import java.awt.*;
import java.util.*;
import javax.swing.*;
import java.io.*;
import com.heaton.bot.*;

/**
* Example program from Chapter 4
* Programming Spiders, Bots and Aggregators in Java
* Copyright 2001 by Jeff Heaton
*
*
* This program accepts a URL as input and then scans all images
* from that one page. These images are saved to the specified
* directory.
*
* @author Jeff Heaton
* @version 1.0
*/
public class GetImage extends javax.swing.JFrame {

/**
* The constructor.
*/
public GetImage()
{
//{{INIT_CONTROLS
setTitle("Download Images");
getContentPane().setLayout(null);
setSize(405,305);
setVisible(false);
JLabel1.setHorizontalTextPosition(javax.swing.SwingConstants.LEFT);
JLabel1.setVerticalTextPosition(javax.swing.SwingConstants.TOP);
JLabel1.setVerticalAlignment(javax.swing.SwingConstants.TOP);
JLabel1.setText("Download images from(one page only):");
getContentPane().add(JLabel1);
JLabel1.setBounds(12,12,384,24);
JLabel2.setText("URL:");
getContentPane().add(JLabel2);
JLabel2.setBounds(12,36,36,24);
getContentPane().add(_url);
_url.setBounds(48,36,348,24);
JLabel3.setText("Select local path to download images to:");
getContentPane().add(JLabel3);
JLabel3.setBounds(12,72,384,24);
getContentPane().add(_save);
_save.setBounds(12,96,384,24);
JScrollPane1.setOpaque(true);
getContentPane().add(JScrollPane1);
JScrollPane1.setBounds(12,168,384,132);
JScrollPane1.getViewport().add(_log);
_log.setBounds(0,0,381,129);
_go.setText("GO!");
getContentPane().add(_go);
_go.setBounds(84,132,216,24);
_go.setActionCommand("jbutton");
//}}

//{{INIT_MENUS
//}}

//{{REGISTER_LISTENERS
SymAction lSymAction = new SymAction();
_go.addActionListener(lSymAction);
//}}
setLocation(32,32);
}

/**
* Added by Visual Cafe.
*
* @param b
*/
public void setVisible(boolean b)
{
if ( b )
setLocation(50, 50);
super.setVisible(b);
}

/**
* Program entry point.
*
* @param args
*/
static public void main(String args[])
{
(new GetImage()).setVisible(true);
}

/**
* Added by Visual Cafe.
*/
public void addNotify()
{
// Record the size of the window prior to calling parents addNotify.
Dimension size = getSize();

super.addNotify();

if ( frameSizeAdjusted )
return;
frameSizeAdjusted = true;

// Adjust size of frame according to the insets and menu bar
Insets insets = getInsets();
javax.swing.JMenuBar menuBar = getRootPane().getJMenuBar();
int menuBarHeight = 0;
if ( menuBar != null )
menuBarHeight = menuBar.getPreferredSize().height;
setSize(insets.left +
insets.right +
size.width,
insets.top +
insets.bottom +
size.height + menuBarHeight);
}

// Used by addNotify
boolean frameSizeAdjusted = false;

//{{DECLARE_CONTROLS
javax.swing.JLabel JLabel1 = new javax.swing.JLabel();
javax.swing.JLabel JLabel2 = new javax.swing.JLabel();

/**
* The URL to be scanned for images.
*/
javax.swing.JTextField _url = new javax.swing.JTextField();
javax.swing.JLabel JLabel3 = new javax.swing.JLabel();

/**
* The directory that these images are to be saved in.
*/
javax.swing.JTextField _save = new javax.swing.JTextField();
javax.swing.JScrollPane JScrollPane1 = new javax.swing.JScrollPane();

/**
* Progress display.
*/
javax.swing.JList _log = new javax.swing.JList();

/**
* Button to be pressed to start the scan.
*/
javax.swing.JButton _go = new javax.swing.JButton();
//}}

//{{DECLARE_MENUS
//}}


class SymAction implements java.awt.event.ActionListener {
public void actionPerformed(java.awt.event.ActionEvent event)
{
Object object = event.getSource();
if ( object == _go )
Go_actionPerformed(event);
}
}

/**
* Called for each image. The name(URL) of each image
* is passed to this method so it can be retrieved and
* saved.
*
* @param name The complete URL to an image to save.
*/
protected void processURL(String name)
{
try {
if ( _save.getText().length()>0 ) {
int i = name.lastIndexOf('/');
if ( i!=-1 ) {
FileOutputStream fso
= new FileOutputStream(
new File(_save.getText(),name.substring(i)) );
HTTPSocket http = new HTTPSocket();
http.send(name,null);
fso.write(http.getBody().getBytes("8859_1") );
fso.close();
}
}
} catch ( Exception e ) {
JOptionPane.showMessageDialog(this,
e,
"Error",
JOptionPane.OK_CANCEL_OPTION,
null );
}
}

/**
* This is where most of the action takes place. This
* method is called when the GO! button is pressed.
*
* @param event The event
*/
void Go_actionPerformed(java.awt.event.ActionEvent event)
{
try {
// open the connection and get the page.
HTTPSocket http = new HTTPSocket();
HTMLPage page = new HTMLPage(http);
page.open(_url.getText(),null);

// look at the images.
Vector vec = page.getImages();
if ( vec.size()>0 ) {
// copy the images to an array for display
String array[] = new String[vec.size()];
vec.copyInto(array);
_log.setListData( array );
// loop through and process each image
for ( int i=0;i<vec.size();i++ )
processURL((String)vec.elementAt(i));
}
} catch ( Exception e ) {
String s[] = new String[1];
s[0] = "Error: " + e;
_log.setListData( s );
}
}
}