下载图片并保存到本地

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;


public class DownLoadImg {

/**
* @param args
*/
public static void main(String[] args) {
String urlFilePath = "http://mt1.google.cn/vt/v=w2.114&hl=zh-CN&gl=cn&x=1&y=1&z=1";
// String urlFilePath = "http://www.google.cn/intl/zh-CN/images/logo_cn.gif";
String fileFolder = "F:/Google/";
String fileName = "google.png";

String filePath = fileFolder + fileName;
makeDir(fileFolder);

try {
getImageFromUrl(urlFilePath, filePath,1);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("\n  >>> IMAGE DOWNLOAD DONE! <<<\n");
openFileSystemDir(fileFolder);
}

private static void getImageFromUrl(String url, String newFilePath, int sizeReduceRank)
throws MalformedURLException, IOException {
if (url == null)
return;

URL u = new URL(url);
// 打开连接
URLConnection con = u.openConnection();

// 设置Java服务器代理连接，要不然报错403
// 浏览器可以访问此url图片并显示，但用Java程序就不行报错Server returned HTTP response code:403 for URL
// 具体原因：服务器的安全设置不接受Java程序作为客户端访问(被屏蔽)，解决办法是设置客户端的User Agent
con.setRequestProperty("User-Agent", "Mozilla/4.0(compatible;MSIE 5.0;Windows NT;DigExt)");

// 输入流
InputStream is = con.getInputStream();

Image image = javax.imageio.ImageIO.read(is);
// Image image = javax.imageio.ImageIO.read(new URL(url));
int width = image.getWidth(null) / sizeReduceRank;
int height = image.getHeight(null) / sizeReduceRank;
// 更改图片大小 sizeRank是原图的缩小的比例 若为2意思为将下载的文件保存为原理图片长宽的1/2
BufferedImage bufferedImage = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
bufferedImage.getGraphics().drawImage(image, 0, 0, width, height, null);
FileOutputStream out = new FileOutputStream(newFilePath);
encode(out, bufferedImage);
out.close();
}

protected static void encode(FileOutputStream out, BufferedImage bufferedImage)
throws ImageFormatException, IOException {
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(bufferedImage);
}

private static void makeDir(String fileFolder) {
File file = new File(fileFolder);
if (!file.exists() && !file.isDirectory())
file.mkdir();
}

private static void openFileSystemDir(String dir) {
String openDirCmdString = "cmd.exe /c start ";
String openDirCmd = openDirCmdString + dir;
System.out.println(openDirCmd);
try {
Runtime r = Runtime.getRuntime();
Process p = r.exec(openDirCmd);
BufferedReader bf = new BufferedReader(new InputStreamReader(
p.getInputStream()));
String line = "";
while ((line = bf.readLine()) != null)
System.out.println(line);
} catch (Exception e) {
e.printStackTrace();
}
}
}