具体错误

responseType' must not be null

java.lang.IllegalArgumentException: 'responseType' must not be null
	at org.springframework.util.Assert.notNull(Assert.java:201)
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
	*__checkpoint ⇢ Handler org.jetlinks.community.device.web.DeviceInstanceController#getDeviceYuntaiStatus(String) [DispatcherHandler]
Original Stack Trace:
		at org.springframework.util.Assert.notNull(Assert.java:201)
		at org.springframework.web.client.HttpMessageConverterExtractor.<init>(HttpMessageConverterExtractor.java:76)
		at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:339)

• 解决办法

设置为json/text皆可。