Tomcat启动时报错：java.net.UnknownHostException

异常信息如下：

INFO: Failed to get local InetAddress for VMID. This is unlikely to matter. At all. We'll add some extra randomness
java.net.UnknownHostException: ran-oam: ran-oam: Name or service not known
    at java.net.InetAddress.getLocalHost(InetAddress.java:)
    at com.mchange.v2.uid.UidUtils.generateVmId(UidUtils.java:)
    at com.mchange.v2.uid.UidUtils.<clinit>(UidUtils.java:)
    at com.mchange.v2.c3p0.impl.C3P0ImplUtils.<clinit>(C3P0ImplUtils.java:)
    at com.mchange.v2.c3p0.impl.PoolBackedDataSourceBase.<init>(PoolBackedDataSourceBase.java:)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.<init>(AbstractPoolBackedDataSource.java:)
    at com.mchange.v2.c3p0.AbstractComboPooledDataSource.<init>(AbstractComboPooledDataSource.java:)
    at com.mchange.v2.c3p0.AbstractComboPooledDataSource.<init>(AbstractComboPooledDataSource.java:)
    at com.mchange.v2.c3p0.ComboPooledDataSource.<init>(ComboPooledDataSource.java:)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:)
    at org.springframework.beans.factory.support.AbstractBeanFactory$.getObject(AbstractBeanFactory.java:)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:)
    at java.util.concurrent.FutureTask.run(FutureTask.java:)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:)
    at java.lang.Thread.run(Thread.java:)
Caused by: java.net.UnknownHostException: ran-oam: Name or service not known
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
    at java.net.InetAddress$.lookupAllHostAddr(InetAddress.java:)
    at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:)
    at java.net.InetAddress.getLocalHost(InetAddress.java:)
    ...  more

解决办法，配置主机名。

查看主机名：

echo `hostname`

执行上述命令后，会打印出主机名，将此记下，后面要用。比如我的主机名为“ran-oam”

修改文件：

vi /etc/hosts

将主机名写入，如下图

完成如上修改后，重新启动Tomcat，发现问题解决。