Java Network - 如何同步数组列表...

import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.Authenticator;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.PasswordAuthentication;
import java.net.Proxy;
import java.net.SocketAddress;
import java.net.URL;

class ProxyAuthenticator extends Authenticator {

  private String userName, password;

  public ProxyAuthenticator(String userName, String password) {
    this.userName = userName;
    this.password = password;
  }

  protected PasswordAuthentication getPasswordAuthentication() {
    return new PasswordAuthentication(userName, password.toCharArray());
  }
}

public class Main {
  public static void main(String[] args) throws Exception {
    downloadFromUrl("http://www.w3cschool.cn/style/download.png");
  }

  private static String getOutputFileName(URL url) {
    String[] urlParts = url.getPath().split("/");
    return "c:/temp/" + urlParts[urlParts.length - 1];
  }

  private static void downloadFromUrl(String urlString) throws Exception {
    InputStream is = null;
    FileOutputStream fos = null;

    URL url = new URL(urlString);

    System.out.println("Reading..." + url);

    Authenticator.setDefault(new ProxyAuthenticator("username", "password"));

    SocketAddress addr = new InetSocketAddress("your proxyserver ip address", 80);
    Proxy proxy = new Proxy(Proxy.Type.HTTP, addr);

    HttpURLConnection conn = (HttpURLConnection) url.openConnection(proxy);

    is = conn.getInputStream();

    String filename = getOutputFileName(url);

    fos = new FileOutputStream(filename);

    byte[] readData = new byte[1024];

    int i = is.read(readData);

    while (i != -1) {
      fos.write(readData, 0, i);
      i = is.read(readData);
    }

    System.out.println("Created file: " + filename);
    System.out.println("Completed");
  }
}