最近在爬一些国外数据，需要挂代理请求一些网站，然而由于代理机器的验证问题，导致设置代理失败，几番面向搜索编程过后，发现Java自带一系统级对象，号曰：Authenticator，当你调用它的setDefault()时，你就已经成功了

上代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Authenticator;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.PasswordAuthentication;
import java.net.URL;

public class AccessPasswordProtectedURLWithAuthenticator {
    public static void main(String[] args) {
        try {
            // Sets the authenticator that will be used by the networking code
            // when a proxy or an HTTP server asks for authentication.
            Authenticator.setDefault(new CustomAuthenticator());
            URL url = new URL("http://www.secure-site-example.com:80/");
            // read text returned by server
            BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
            String line;
            while ((line = in.readLine()) != null) {
                System.out.println(line);
            }
            in.close();    
        }
        catch (MalformedURLException e) {
            System.out.println("Malformed URL: " + e.getMessage());
        }
        catch (IOException e) {
            System.out.println("I/O Error: " + e.getMessage());
        }
    }
     
    public static class CustomAuthenticator extends Authenticator {
        // Called when password authorization is needed
        protected PasswordAuthentication getPasswordAuthentication() {
            // Get information about the request
            String prompt = getRequestingPrompt();
            String hostname = getRequestingHost();
            InetAddress ipaddr = getRequestingSite();
            int port = getRequestingPort();
            String username = "username";
            String password = "password";
            // Return the information (a data holder that is used by Authenticator)
            return new PasswordAuthentication(username, password.toCharArray());        
        }    
    }
}

正常我们如果没有什么特殊的需求，这么写就行

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

因为这个是系统级的，所以在所有请求发送前设置这个都是有效的，但我心里总有些不安，感觉好像有什么隐患。。。