开发技巧-Java通过HttpProxy实现穿越

/**
 * 网络代理測试
 * 
 * <pre>
 * 设置代理主机及port：系统变量(https 需同步设置)
 * 设置代理验证方式：全局代理对象
 * 
 * 
 * https链接错误：
 * Unable to tunnel through proxy. Proxy returns "HTTP/1.0 407 Proxy Authentication Required"
 * 使用全局代理验证解决
 * 
 * </pre>
 * 
 * @author tzz
 * @createDate 2015年7月23日
 * 
 */
public class ProxyTest {
    private static String proxyHost = "xxx.xxxxx.com";
    private static int proxyPort = 8080;
    private static String proxyUser = "user";
    private static String proxyPass = "pass";
    public static void main(String[] args) {
        String url = "https://www.google.com/";
        String content = doProxy(url);
        System.out.println("Result :===================\n " + content);
    }
    /**
     * 通过系统变量方式实现代理
     * 
     * @param url
     * @return
     */
    public static String doProxy(String url) {
        // 设置系统变量

        System.setProperty("http.proxySet", "true");
        System.setProperty("http.proxyHost", proxyHost);
        System.setProperty("http.proxyPort", "" + proxyPort);
        // 针对https也开启代理
        System.setProperty("https.proxyHost", proxyHost);
        System.setProperty("https.proxyPort", "" + proxyPort);
        // 设置默认校验器
        setDefaultAuthentication();

        //開始请求
        try {
            URL u = new URL(url);
            URLConnection conn = u.openConnection();
            HttpsURLConnection httpsCon = (HttpsURLConnection) conn;
            httpsCon.setFollowRedirects(true);

            String encoding = conn.getContentEncoding();
            if (StringUtils.isEmpty(encoding)) {
                encoding = "UTF-8";
            }
            InputStream is = conn.getInputStream();
            String content = IOUtils.toString(is, encoding);
            return content;
        } catch (Exception e) {
            e.printStackTrace();
            return e.getMessage();
        }
    }

    /**
     * 设置全局校验器对象
     */
    public static void setDefaultAuthentication() {
        BasicAuthenticator auth = new BasicAuthenticator(proxyUser, proxyPass);
        Authenticator.setDefault(auth);
    }
}

    /**
     * 实现sun.net的代理验证
     * 
     * @author tzz
     * @createDate 2015年7月23日
     * 
     */
    public static class BasicAuthenticator extends Authenticator {
        String userName;
        String password;
        public BasicAuthenticator(String userName, String password) {
            this.userName = userName;
            this.password = password;
        }
        /**
         * Called when password authorization is needed. Subclasses should override the default implementation, which returns null.
         * 
         * @return The PasswordAuthentication collected from the user, or null if none is provided.
         */
        @Override
        protected PasswordAuthentication getPasswordAuthentication() {
            //System.out.println("DEBUG === use global authentication of password");
            return new PasswordAuthentication(userName, password.toCharArray());
        }
    }