解决一些Springboot启动报错问题

常见的两个原因:

1、

控制台信息如下：

Connected to the target VM, address: ‘127.0.0.1:50617’, transport: ‘socket’
Disconnected from the target VM, address: ‘127.0.0.1:50617’, transport: ‘socket’
Process finished with exit code 0　　

原因是某个 .xml文件 被注释 释放即可，！

2、

报错信息如下
org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:155) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at com.ecjtu.demo.DemoApplication.main(DemoApplication.java:15) [classes/:?]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.(TomcatWebServer.java:86) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:409) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	... 8 more
Caused by: java.lang.IllegalStateException: StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[] failed to start
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.rethrowDeferredStartupExceptions(TomcatWebServer.java:172) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:110) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.(TomcatWebServer.java:86) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:409) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	... 8 more

1、首先得去看配置文件application.yml，pom.xml,程序入口类。这三个

2、把@EnableEurekaServer注解和关于eureka的配置都去掉 如果可以跑起来 就去引入jaxb-api；

注:从java9开始，模块化的概念使JAXB默认没有加载；jaxb-api是存在jdk中的，只是默认没有加载而已，我们需要手动引入。要问这个jaxb-api是什么作用 大家可以去百度一下