KerberosUtil

package com.huawei.bigdata.security;

import org.apache.log4j.Logger;

import java.lang.reflect.Method;

public class KerberosUtil {

private static Logger logger = Logger.getLogger(KerberosUtil.class);

public static final String JAVA_VENDER = "java.vendor";
public static final String IBM_FLAG = "IBM";
public static final String CONFIG_CLASS_FOR_IBM = "com.ibm.security.krb5.internal.Config";
public static final String CONFIG_CLASS_FOR_SUN = "sun.security.krb5.Config";
public static final String METHOD_GET_INSTANCE = "getInstance";
public static final String METHOD_GET_DEFAULT_REALM = "getDefaultRealm";
public static final String DEFAULT_REALM = "HADOOP.COM";

public static String getKrb5DomainRealm() {
    Class<?> krb5ConfClass;
    String peerRealm;
    try {
        if (System.getProperty(JAVA_VENDER).contains(IBM_FLAG)) {
            krb5ConfClass = Class.forName(CONFIG_CLASS_FOR_IBM);
        } else {
            krb5ConfClass = Class.forName(CONFIG_CLASS_FOR_SUN);
        }

        Method getInstanceMethod = krb5ConfClass.getMethod(METHOD_GET_INSTANCE);
        Object kerbConf = getInstanceMethod.invoke(krb5ConfClass);

        Method getDefaultRealmMethod = krb5ConfClass.getDeclaredMethod(METHOD_GET_DEFAULT_REALM);
        peerRealm = (String)getDefaultRealmMethod.invoke(kerbConf);
        logger.info("Get default realm successfully, the realm is : " + peerRealm);

    } catch (Exception e) {
        peerRealm = DEFAULT_REALM;
        logger.warn("Get default realm failed, use default value : " + DEFAULT_REALM);
    }

    return peerRealm;
}

}