阿里云部署的web项目请求容联接口发起https请求总是失败

项目中集成了第三方接口，为 https 协议，在本地 部署 可以调用，但是部署到 阿里云 上后就调用不了了。 后面阿里云上提了个工单，也没出结果，他们说云 服务器 是没有限制的，不会是服务器的 问题 第三方的证书我也 下载 下来了，导入到了jre的cacerts库中,有没有人知道大概怎么回事的
发送 POST 请求出现异常！

javax.net.ssl.SSLException: java.security.ProviderException: java.security.KeyException
        at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1916)
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1874)

public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {


            //生成auth
            String src = AccountSid + ":" + timestamp;
            log.info("###################url:"+url);
            String auth = new sun.misc.BASE64Encoder().encode(src.getBytes() );
            log.info("###################auth:"+auth);
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            HttpsURLConnection conn = (HttpsURLConnection)realUrl.openConnection();
           // URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "application/xml");
            conn.setRequestProperty("connection", "close");
            conn.setRequestProperty("content-type","application/xml;charset=utf-8");
            conn.setRequestProperty("authorization",auth);
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream(),"utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        //System.out.println(result);
        return result;
    }