Java o.s.boot.SpringApplication : Application startup failed

2022-10-12 17:50:29.285  WARN 2763 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is java.lang.NullPointerException
2022-10-12 17:50:29.291 ERROR 2763 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is java.lang.NullPointerException
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:133) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at com.baidu.fsg.anymock.runner.ApplicationTestRunner.main(ApplicationTestRunner.java:44) [test-classes/:na]
Caused by: java.lang.NullPointerException: null
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:160) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]

解决办法尝试记录：

1.) ~[spring-boot-1.3.3.RELEASE.jar:1.3.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532) ~[spring-context-4.2.5.RELEASE.jar:4.2.5.RELEASE]
    at 

抛出异常的根源所在的源码,通过查看源码得出是启动时从beanFactory中找不到所需bean的存在,也就是bean根本没有注册：

protected EmbeddedServletContainerFactory getEmbeddedServletContainerFactory() {
        String[] beanNames = this.getBeanFactory().getBeanNamesForType(EmbeddedServletContainerFactory.class); --这里通过类型去查询bean，结果发现一个都没有就抛出异常了，当然如果超过一个也会抛出异常
        if (beanNames.length == 0) {
            throw new ApplicationContextException("Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.");
        } else if (beanNames.length > 1) {
            throw new ApplicationContextException("Unable to start EmbeddedWebApplicationContext due to multiple EmbeddedServletContainerFactory beans : " + StringUtils.arrayToCommaDelimitedString(beanNames));
        } else {
            return (EmbeddedServletContainerFactory)this.getBeanFactory().getBean(beanNames[0], EmbeddedServletContainerFactory.class);
        }
    }

4、启动类中添加注解

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

    @EnableEurekaServer
    @SpringBootApplication
    
 5、注解标注了这个启动类，但是还是提示Cannot resolve symbol *等问题，一定要去检查引包是否正确