首先这是端口被占用的意思

org.apache.catalina.LifecycleException: Protocol handler start failed
 at org.apache.catalina.connector.Connector.startInternal(Connector.java:1008) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
 at org.apache.catalina.core.StandardService.addConnector(StandardService.java:226) [tomcat-embed-core-9.0.17.jar:9.0.17]
 at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.addPreviouslyRemovedConnectors(TomcatWebServer.java:259) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
 at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.start(TomcatWebServer.java:197) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
 at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.startWebServer(ServletWebServerApplicationContext.java:311) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
 at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:164) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
 at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552) [spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]

Caused by: java.net.BindException: Address already in use: bind
 at java.base/sun.nio.ch.Net.bind0(Native Method) ~[na:na]
 at java.base/sun.nio.ch.Net.bind(Net.java:433) ~[na:na]
 at java.base/sun.nio.ch.Net.bind(Net.java:425) ~[na:na]
 at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:225) ~[na:na]
 at java.base/sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[na:na]
 at org.apache.tomcat.util.net.NioEndpoint.initServerSocket(NioEndpoint.java:236) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
 at org.apache.tomcat.util.net.NioEndpoint.bind(NioEndpoint.java:210) ~[tomcat-embed-core-9.0.17.jar:9.0.17]

这时候我们就打开cmd输入

netstat -ano | findstr 8001    //8001改为你觉得占用的端口号

会出现这个

C:\Users\user>netstat -ano | findstr 8001
  TCP    0.0.0.0:8001           0.0.0.0:0              LISTENING       12432
  TCP    [::]:8001              [::]:0                 LISTENING       12432

我们把他停止掉

C:\Users\user>taskkill -f -pid 12432  //12432是刚刚查出来的后面跟的pid
成功: 已终止 PID 为 12432 的进程。

这样就停止掉了，如果还不行的话就要查看这个进程的名字，然后去服务里停止