java.io.IOException: Error writing to server

Question

private Map<String,Object> invokePostFile(String ip,int port,String uri,boolean allowNoReponse,Map<String,Object> params,File f,String...requKey) throws Exception{        if(StringUtils.isBlank(ip) || port == 0){            throw new UEException("未获取到调度引擎地址");        }        final String BOUNDARY = UUID.randomUUID().toString();        final String PREFFIX = "--", LINEND = "\r\n";        String address = "https://"+ip+":"+port+uri;        HttpURLConnection connection = (HttpURLConnection)new URL(address).openConnection();        DataOutputStream outputStream = null;        try {            connection.setConnectTimeout(TIMEOUT);            connection.setReadTimeout(TIMEOUT);            connection.setDoOutput(true);            connection.setDoInput(true);            connection.setRequestMethod("POST");            connection.setInstanceFollowRedirects(true);            connection.setUseCaches(false);            connection.setRequestProperty("connection", "keep-alive");            connection.setRequestProperty("Charset", "UTF-8");            connection.setRequestProperty("Content-Type","multipart/form-data;boundary=" + BOUNDARY);            StringBuilder sb = new StringBuilder();            for (Map.Entry<String, Object> entry : params.entrySet()) {                sb.append(PREFFIX);                sb.append(BOUNDARY);                sb.append(LINEND);                sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"" + LINEND);                sb.append("Content-Type: text/plain; charset=UTF-8" + LINEND);                sb.append("Content-Transfer-Encoding: 8bit" + LINEND);                sb.append(LINEND);                sb.append(entry.getValue());                sb.append(LINEND);            }            //参数            connection.setRequestProperty(SIGN_KEY,SecretUtil.encryptHMAC(SecretUtil.HMAC_SHA256,sb.toString().getBytes("UTF8"),ENGINE_PASSWORD));            //如果是https            if(connection instanceof HttpsURLConnection){                SSLContext sc = SSLContext.getInstance("SSL");                sc.init(null,new TrustManager[]{new X509TrustManager(){                    @Override                    public void checkClientTrusted(X509Certificate[] arg0,String arg1) throws CertificateException {                    }                    @Override                    public void checkServerTrusted(X509Certificate[] arg0,String arg1) throws CertificateException {                    }                    @Override                    public X509Certificate[] getAcceptedIssuers() {                        return new X509Certificate[]{};                    }                }},new java.security.SecureRandom());                ((HttpsURLConnection)connection).setSSLSocketFactory(sc.getSocketFactory());                ((HttpsURLConnection)connection).setHostnameVerifier(new HostnameVerifier(){                    @Override                    public boolean verify(String arg0, SSLSession arg1) {                        return true;                    }                });            }            try {                connection.connect();            } catch (Exception e) {                LOG.error("引擎连接失败："+address,e);                throw new UEException("引擎连接失败",e);            }            //写入参数           outputStream = new DataOutputStream(connection.getOutputStream());           outputStream.write(sb.toString().getBytes("UTF8"));            if(f !=null && f.exists()){                String fileName = f.getName();                StringBuilder sb1 = new StringBuilder();                sb1.append(PREFFIX);                sb1.append(BOUNDARY);                sb1.append(LINEND);                sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\"" + fileName + "\"" + LINEND);                sb1.append("Content-Type: application/octet-stream;chartset=UTF-8" + LINEND);                sb1.append(LINEND);                 // 写入到输出流中                outputStream.write(sb1.toString().getBytes());                DataInputStream is = null;                try {                    // 将文件读入输入流中                    is = new DataInputStream(new FileInputStream(f));;                    byte[] buffer = new byte[1024];                    int len = 0;                    while ((len = is.read(buffer)) != -1) {                        outputStream.write(buffer, 0, len);                    }                    //footer                    outputStream.write((PREFFIX + BOUNDARY + PREFFIX + LINEND).getBytes("UTF8"));                    outputStream.flush();                } catch (Exception e) {                    throw e;                }finally{                    IOUtils.closeQuietly(is);                }            }            //读取结果            return parseRepose(connection,requKey,allowNoReponse);        }catch(Exception e){            if(e instanceof UEException){                throw e;            }            throw new UEException("引擎执行失败",e);        }finally{            IOUtils.closeQuietly(outputStream);            connection.disconnect();        }    }错误信息：