org.apache.http.NoHttpResponseException: api.mch.weixin.qq.com:443 failed to respond
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
您好，报这个错误，一般是你退款证书错误引起，请按照以下几点检查：
1，退款证书过期或证书错误，请到对应的商户平台下载证书并正确使用
2，调用退款证书路径要用绝对路径
3，如果是服务商模式退款 ，请使用服务商的证书
4，请检查服务器是否有正确安装退款证书
（退款证书使用指引：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=4_3）