Question

当我想在同一个tomcat上部署多个Spring-Boot应用程序时，我会遇到多个问题。

1）两个应用程序必须共享相同的tomcat才能独立运行。在同一个tomcat上部署两个Spring-Boot应用程序时，出现以下异常：

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-03-06 17:31:01 ERROR o.s.boot.SpringApplication - Application run failed
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:625)
    at org.springframework.jmx.export.MBeanExporter.lambda$registerBeans$2(MBeanExporter.java:551)
    at java.util.HashMap.forEach(HashMap.java:1289)
    at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:551)
    at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:434)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:863)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:157)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:137)
    at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:171)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5267)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    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.deployDescriptor(HostConfig.java:629)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1839)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
    at java.util.concurrent.FutureTask.run(FutureTask.java)
    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: 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:137)
    at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:671)
    at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:615)
    ... 28 common frames omitted

2）我需要为两个应用程序都提供外部配置，需要明确的是每个应用程序都使用正确的配置。

Answer 1

1）当两个Spring-Boot应用程序在同一个tomcat上运行时，通常会遇到一个问题，即数据源的实例化可能会失败，因为同名实例已经存在。这是您在问题中描述的例外情况。

这可以通过在每个Spring-Boot应用程序中添加一个唯一的名称来解决，例如

application.yml

spring:
  application:
    name: application-name-1
  jmx:
    default-domain: application-name-1

2）可以通过单独为每个应用程序的tomcat上下文配置为每个Spring-Boot应用程序提供外部配置。假设所有应用程序都部署为.war，例如app1.war，app2.war，我们需要为以下两个应用程序配置上下文：

创建以下文件（和目录，如果缺少）

tomcat-base-dir
  /conf
    /catalina
      /localhost #must be the same as specified in the Host tag in the server.xml
        app1.xml #must have the same name as the .war application file
        app2.xml

app1.xml

的内容

<?xml version="1.0" encoding="UTF-8"?>
<!-- docBase must contain be the name of the application to be configured -->
<Context docBase="app1.war"> 
    <Parameter name="spring.config.location" value="${catalina.base}/conf/app1.yml" />
</Context>

这将配置应用程序app1.war以使用文件app1.yml进行配置。对app2执行相同的操作。实际的配置文件app1.yml可以位于该值指定的任何路径中。

如何在同一个Tomcat上部署具有外部配置的多个Spring Boot应用程序？

1 个答案: