java jsoup 使用代理方式，请求资源。

    private Document requestDoc(String url)
    {
        Document doc = null;
        try
        {
            System.setProperty("https.proxySet", "true");
            System.getProperties().put("https.proxyHost", "127.0.0.1");
            System.getProperties().put("https.proxyPort", 8580);
            Map<String, String> headers = new HashMap<String, String>();
            headers.put("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8");
            headers.put("Accept-Language", "zh-CN,zh;q=0.9");
            doc = Jsoup.connect(url)
                .userAgent("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.62 Safari/537.36")
                .timeout(20 * 1000)
                .get();
        }
        catch (IOException e)
        {
            log.error("fetchSingleDoc error", e);
        }
        
        return doc;
    }