返回通用认证的HttpConnection对象

最近项目在访问服务器时出现了证书过期问题，需要使用无认证的连接来向服务器请求数据，方法如下：

public static HttpURLConnection prepareConnection(            String serverUrl) throws IOException, MalformedURLException, ProtocolException {        // Create a trust manager that does not validate certificate chains        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {            public java.security.cert.X509Certificate[] getAcceptedIssuers() {                return null;            }            public void checkClientTrusted(                    java.security.cert.X509Certificate[] certs, String authType) {            }            public void checkServerTrusted(                    java.security.cert.X509Certificate[] certs, String authType) {            }        } };        // Install the all-trusting trust manager        try {            SSLContext sc = SSLContext.getInstance("SSL");            sc.init(null, trustAllCerts, new java.security.SecureRandom());            HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());        } catch (GeneralSecurityException e) {        }        // Now you can access an https URL without having the certificate in the        // truststore        URL url = new URL(serverUrl);        HttpURLConnection urlConnection = null;        urlConnection = (HttpURLConnection) url.openConnection();        urlConnection.setRequestMethod("GET");        urlConnection.setConnectTimeout(Constants.TIMEOUT_4_CONN);      // 设置连接主机超时        urlConnection.setReadTimeout(Constants.TIMEOUT_4_READ);         // 设置读取数据超时        urlConnection.setDoInput(true);        urlConnection.setDoOutput(true);        urlConnection.connect();                                        // 打开连接        return urlConnection;    }