springboot启动报错Unable to start embedded container

如果你的springboot在启动的时候报如下的错误：

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2019-08-13 17:02:05.907 ERROR 8416 --- [  restartedMain] o.s.boot.SpringApplication               : Application startup failed

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
	at com.hzsun.Application.main(Application.java:26)
	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:497)
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:123)
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.(TomcatEmbeddedServletContainer.java:84)
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:554)
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:179)
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164)
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134)
	... 13 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
	at org.apache.catalina.startup.Tomcat.start(Tomcat.java:367)
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:99)
	... 18 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 20 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
	at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 22 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
	at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:947)
	at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 24 common frames omitted

总结起来主要有2点错误：

1.springboot的错误： Unable to start embedded container

2.内嵌的tomcat报错：A child container failed during start

如果你折腾了很久，试了网上各种抄来抄去的解决方案，查了tomcat的环境变量，重新更了代码和仓库，项目编译无任错误，也查了jetty可以替换，但是项目启动依然会报这个错的话......那么请看下面的解决办法；

解决办法：

检查一下项目的正在使用到的jdk，是否引入的jre里面有servlet-api.jar包，如果有那么恭喜你，问题就是这里了，springboot内嵌的tomcat有servlet-api的功能，跟jre里的servlet-api是冲突的哟，要么删除jre下面那个jar包，要么在项目pom.xml文件里面重新声明tomcat并将其servl-api.jar排除，问题就解决了！