近期封裝Ozone客戶端，需要走kerberos登陸，遇到了一個問題，花了很長時間解決。記錄一下，跟網上能搜到的解決方案不大一樣。
先看有問題的代碼

            Configuration config = new Configuration();ConfigurationUtils.setHadoopConfig(config, basePath);config.set("hadoop.security.authentication", "kerberos");UserGroupInformation.setConfiguration(config);System.setProperty("java.security.krb5.conf", basePath + ozoneProperties.getKrb5Conf());// 登錄KerberosUserGroupInformation.loginUserFromKeytab(ozoneProperties.getPrincipal(), basePath + ozoneProperties.getKeytab());
//            UserGroupInformation.loginUserFromKeytab(ozoneProperties.getPrincipal(), "D:\\gitee\\bigdata-eis-platform\\eis-framework\\eis-framework-starter-ozone-oss\\src\\test\\resources\\prd\\ic.bigdatamgr.keytab");// 配置Ozone客戶端OzoneConfiguration conf = new OzoneConfiguration();conf.addResource(new Path(basePath + ozoneProperties.getOzoneSite()));OzoneClient ozClient = OzoneClientFactory.getRpcClient(conf);return ozClient;

運行的時候報入下錯誤:

java.lang.IllegalArgumentException: Can't get Kerberos realmat org.apache.hadoop.security.HadoopKerberosName.setConfiguration(HadoopKerberosName.java:71)at org.apache.hadoop.security.UserGroupInformation.initialize(UserGroupInformation.java:315)at org.apache.hadoop.security.UserGroupInformation.setConfiguration(UserGroupInformation.java:366)at com.byd.bigdata.eis.framework.ozone.oss.autoconfig.OzoneAutoConfiguration.initOzoneClient(OzoneAutoConfiguration.java:44)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653)at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:486)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:955)at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:921)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:731)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408)at org.springframework.boot.SpringApplication.run(SpringApplication.java:307)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303)at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292)at com.byd.bigdata.eis.module.datareportsystem.DatareportSystemApplication.main(DatareportSystemApplication.java:13)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:65)
Caused by: java.lang.IllegalArgumentException: KrbException: Cannot locate default realmat javax.security.auth.kerberos.KerberosPrincipal.<init>(KerberosPrincipal.java:154)at org.apache.hadoop.security.authentication.util.KerberosUtil.getDefaultRealm(KerberosUtil.java:120)at org.apache.hadoop.security.HadoopKerberosName.setConfiguration(HadoopKerberosName.java:69)36 common frames omitted

錯誤原因：hadoop的配置加載放在了kerberos的配置的前面，導致hadoop加載配置找不到kerberos的相關配置，所以報這個錯誤
解決辦法：把加載kerberos配置的代碼放在最前面即可