springboot项目:Connector configured to listen on port 端口号 failed to start

报错信息如下

2020-03-24 14:36:12.437 [restartedMain] DEBUG - o.s.b.d.LoggingFailureAnalysisReporter  [38] : Application failed to start due to an exception
org.springframework.boot.web.embedded.tomcat.ConnectorStartFailedException: Connector configured to listen on port 8981 failed to start
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.checkConnectorHasStarted(TomcatWebServer.java:232)
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.checkThatConnectorsHaveStarted(TomcatWebServer.java:224)
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.start(TomcatWebServer.java:202)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.startWebServer(ServletWebServerApplicationContext.java:300)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
	at com.ultronera.spc.SpcApplication.main(SpcApplication.java:33)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)

原因是端口号被占用了, 可以在application.properties里的server.port里修改一下端口号;
也可以在任务管理器中把所有Java开头的进程都关掉,重新起服务.