In the process of learning springboot, we encountered various problems

Error process:

org.apache.catalina.LifecycleException: Failed to start component [Connector[HTTP/1.1-8080]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.apache.catalina.core.StandardService.addConnector(StandardService.java:225) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.addPreviouslyRemovedConnectors(TomcatWebServer.java:256) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.start(TomcatWebServer.java:198) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.startWebServer(ServletWebServerApplicationContext.java:300) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) [spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
	at com.ray.lesson5.Lesson5Application.main(Lesson5Application.java:10) [classes/:na]
Caused by: org.apache.catalina.LifecycleException: Protocol handler start failed
	at org.apache.catalina.connector.Connector.startInternal(Connector.java:1020) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	... 13 common frames omitted
Caused by: java.net.BindException: Address already in use: bind
	at sun.nio.ch.Net.bind0(Native Method) ~[na:1.8.0_161]
	at sun.nio.ch.Net.bind(Net.java:433) ~[na:1.8.0_161]
	at sun.nio.ch.Net.bind(Net.java:425) ~[na:1.8.0_161]
	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) ~[na:1.8.0_161]
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[na:1.8.0_161]
	at org.apache.tomcat.util.net.NioEndpoint.bind(NioEndpoint.java:210) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.apache.tomcat.util.net.AbstractEndpoint.start(AbstractEndpoint.java:1150) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.apache.coyote.AbstractProtocol.start(AbstractProtocol.java:591) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	at org.apache.catalina.connector.Connector.startInternal(Connector.java:1018) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
	... 14 common frames omitted

2018-06-26 20:48:00.990  INFO 15332 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2018-06-26 20:48:00.997  INFO 15332 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-06-26 20:48:01.000 ERROR 15332 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

The Tomcat connector configured to listen on port 8080 failed to start. The port may already be in use or the connector may be misconfigured.

reason:

8080 port is occupied… Confused?It’s not started. It’s occupied

solve:

1. Open the CMD command window   Enter the following command to view all ports and PID

netstat -ano

2. Find the corresponding port and the corresponding PID   Enter the instruction to find the corresponding process

 tasklist | findstr "7676"

3. Kill the process and start it again

  taskkill /f /t /im java.exe