import java.io.*;
import java.net.*;
public class Test {
    public boolean saveUrlAs(String photoUrl, String fileName) {
        //此方法只能用于HTTP协议
        try {
            URL url = new URL(photoUrl);
            HttpURLConnection connection = (HttpURLConnection) url.
                    openConnection();
            DataInputStream in = new DataInputStream(connection.getInputStream());
            DataOutputStream out = new DataOutputStream(new FileOutputStream(fileName));
            byte[] buffer = new byte[4096];
            int count = 0;
            while ((count = in.read(buffer)) > 0) {
                out.write(buffer, 0, count);
            }
            out.close();
            in.close();
            return true;
        } catch (Exception e) {
            return false;
        }
    }
   
    public String getDocumentAt(String urlString) {
        //此方法兼容HTTP和FTP协议
        StringBuffer document = new StringBuffer();
        try {
            URL url = new URL(urlString);
            URLConnection conn = url.openConnection();
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    conn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                document.append(line + "\n");
            }
            reader.close();
        }catch (MalformedURLException e) {
            System.out.println("Unable to connect to URL: " + urlString);
        }catch (IOException e) {
            System.out.println("IOException when connecting to URL: " +
                    urlString);
        }
        return document.toString();
    }
   
    public static void main(String[] args) throws IOException {
        Test test = new Test();
        String photoUrl = "http://www.cjsdn.net/index.html";
        String fileName = photoUrl.substring(photoUrl.lastIndexOf("/"));
        String filePath = "c:";
        boolean flag = test.saveUrlAs(photoUrl, filePath + fileName);
        System.out.println("Run ok!\nGet URL file " + flag);
    }
}