javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake

at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:992)

at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)

at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)

at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)

at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)

at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)

at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1316)

at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1291)

at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)

at com.ruoyi.web.utils.HttpUtil.sendPost(HttpUtil.java:37)

at com.ruoyi.web.utils.WxHttpUtils.postRequest(WxHttpUtils.java:53)

at com.ruoyi.web.utils.WxHttpUtils.commonPost(WxHttpUtils.java:39)

at com.ruoyi.web.service.order.impl.WxOrderServiceImpl.lambda$saveOrder$8(WxOrderServiceImpl.java:530)

at java.util.concurrent.CompletableFuture$AsyncSupply.run$$$capture(CompletableFuture.java:1590)

at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

Caused by: java.io.EOFException: SSL peer shut down incorrectly

public static String sendPost(String url, String param) throws Exception{
    PrintWriter out = null;
    BufferedReader in = null;
    StringBuilder result = new StringBuilder();
    try {
        log.info("sendPost - {}", url);
        URL realUrl = new URL(url);
        URLConnection conn = realUrl.openConnection();
        conn.setRequestProperty("accept", "*/*");
        conn.setRequestProperty("connection", "Keep-Alive");
        conn.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64)");
        conn.setRequestProperty("Accept-Charset", "utf-8");
        conn.setRequestProperty("contentType", "utf-8");
        conn.setDoOutput(true);
        conn.setDoInput(true);
        out = new PrintWriter(conn.getOutputStream());
        out.print(param);
        out.flush();
        in = new BufferedReader(new InputStreamReader(conn.getInputStream(), StandardCharsets.UTF_8));
        String line;
        while ((line = in.readLine()) != null) {
            result.append(line);
        }
        log.info("recv - {}", result);
    } finally {
        try {
            if (out != null) {
                out.close();
            }
            if (in != null) {
                in.close();
            }
        } catch (IOException ex) {
            log.error("调用in.close Exception, url=" + url + ",param=" + param, ex);
        }
    }
    return result.toString();
}