问题：tomcat 项目启动失败（有多个springboot项目）！

28-Apr-2019 12:01:12.162 严重 [localhost-startStop-1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: 
 org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/credit]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:754)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1135)
	at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1869)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [HikariDataSource (HikariPool-2)] with key 'dataSource'; nested exception is javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
	at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:628)
	at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:550)
	at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:432)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:781)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:124)
	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.web.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:156)
	at org.springframework.boot.web.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:136)
	at org.springframework.boot.web.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)
	at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:169)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5225)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 10 more
Caused by: javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
	at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
	at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:195)
	at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:675)
	at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:618)
	... 25 more

28-Apr-2019 12:01:12.162 严重 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Error deploying web application directory [D:\projects\Apache Software Foundation\Tomcat 8.5\webapps\credit]
 java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/credit]]
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:758)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1135)
	at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1869)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

 解决

### 二选一    
### 关闭应用程序管理员 （Spring应用程序管理员JMX自动配置）   默认开启
#spring.jmx.enabled=false  
## 开启应用管理功能。 并命名 防止tomcata多个boot项目启动失败
spring.jmx.default-domain=/credit