问题
Organization provides http proxy and https proxy.
If not within enterprise network successfully establishing a secure connection (ssl://brokerhost:brokerport)
1.Passing relevant keystore and truststore
2.Setting default instance of SSLSocketFactory in MqttConnectOptions.
回答1:
No, for native MQTT there is no way to use a HTTP/HTTPS proxy.
You can not use a HTTP proxy to transport an arbitrary TCP based protocol. You need something like SOCKS (ssh can be used to to setup socks proxies or to do port forwarding to remote [not the ssh host] location)
来源：https://stackoverflow.com/questions/44253083/is-java-client-of-paho-proxy-aware-and-enables-sending-of-mqtt-messages-across-e