Method getCharset

WebCurl/WebCurl.java:145–211

(String link)

    *(2)从主体中匹配获取:"charset"
    * */
    public static String getCharset(String link)  {
        String charset = "utf-8";

        HttpURLConnection conn = null;

        try {
            URL url = new URL(link);

            conn = (HttpURLConnection)url.openConnection();

            conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36");

            conn.connect();
            System.setProperty("sun.net.client.defaultConnectTimeout","30000");
            System.setProperty("sun.net.client.defaultReadTimeout", "30000");

                String contentType = conn.getContentType();

                //在header里面找charset

                charset = findCharset(contentType);
                //System.out.println("header:"+charset);

                //如果没找到的话，则一行一行的读入页面的html代码，从html代码中寻找

                if(charset.isEmpty()){
                    BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));

                    String line = reader.readLine();

                    while(line != null) {
                        if(line.contains("Content-Type")) {
                            // result = findCharset(line);
                            Pattern p = Pattern.compile("content=\"text/html;\\s*charset=([^>]*)\"");
                            Matcher m = p.matcher(line);
                            if (m.find()) {
                                charset = m.group(1);
                                System.out.println("html:"+charset);
                            }
                            break;

                        }

                        line = reader.readLine();

                    }
                    reader.close();

                }




        } catch (Exception e) {
// TODO Auto-generated catch block
            //这里可以打印响应不了的域名错误信息
            //e.printStackTrace();