UnknownHostException

在linux系统下部署Java产品的集群环境时，后台报出如下异常，系统报找不到名为“QATest242”的主机： 
ERROR  - Get local host name failed -com.trs.infra.cluster.ClusterConfig.getMemberHost(ClusterConfig.java:293) 
java.net.UnknownHostException: QATest242: QATest242 
        at java.net.InetAddress.getLocalHost(InetAddress.java:1353) 
        at xxxxxxx 产品异常信息 
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1029) 
        at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862) 
        at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013) 
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4357) 
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:823) 
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807) 
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:595) 
        at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:277) 
        at org.apache.catalina.core.StandardHost.install(StandardHost.java:832) 
        at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:701) 
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:432) 
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:983) 
        at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:349) 
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) 
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1091) 
        at org.apache.catalina.core.StandardHost.start(StandardHost.java:789) 
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1083) 
        at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:478) 
        at org.apache.catalina.core.StandardService.start(StandardService.java:480) 
        at org.apache.catalina.core.StandardServer.start(StandardServer.java:2313) 
        at org.apache.catalina.startup.Catalina.start(Catalina.java:556) 
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
        at java.lang.reflect.Method.invoke(Method.java:597) 
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:287) 
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:425) 

出错的Java代码： 
InetAddress localhost = InetAddress.getLocalHost(); 

解决办法： 
    打开linux机器的etc/hosts文件，在文件最后加上下面这句话，重启ekp应用即可 
192.9.100.242 cluster242.domain QATest242 
192.9.100.242：ip地址 
cluster242.domain：第二位为域名 
QATest242：主机名称 
------------------------------------------ 
测试方案： 
ping  127.0.0.1  可以ping通 
ping  localhost  不通 
说明是主机映射的原因。 
解决方法： 
修改etc/hosts 文件 
[oracle@bogon ~]$ su - root 
Password: 
[root@bogon ~]# cd .. 
[root@bogon /]# cd .. 
[root@bogon /]# cd etc 
[root@bogon etc]# cat hosts 
# Do not remove the following line, or various programs 
# that require network functionality will fail. 
127.0.0.1               bogon.localdomain bogon 
在hosts文件中追加下面一行就OK了： 
127.0.0.1 localhost.localdomain localhost