我正在嘗試使用 log4jdbc 監(jiān)視我的 MySQL 數(shù)據(jù)庫查詢。我有一個運行 Java 8 的 WSO2 身份服務器。我按照 [1] 中的說明進行操作，并收到以下錯誤。[2019-01-11 15:19:37,590] ERROR {org.wso2.carbon.user.core.common.DefaultRealm} -  nullType class java.lang.reflect.InvocationTargetExceptionorg.wso2.carbon.user.core.UserStoreException: nullType class java.lang.reflect.InvocationTargetException    at org.wso2.carbon.user.core.common.DefaultRealm.createObjectWithOptions(DefaultRealm.java:395)    at org.wso2.carbon.user.core.common.DefaultRealm.initializeObjects(DefaultRealm.java:222)    at org.wso2.carbon.user.core.common.DefaultRealm.init(DefaultRealm.java:127)    at org.wso2.carbon.user.core.common.DefaultRealmService.initializeRealm(DefaultRealmService.java:264)    at org.wso2.carbon.user.core.common.DefaultRealmService.<init>(DefaultRealmService.java:102)    at org.wso2.carbon.user.core.common.DefaultRealmService.<init>(DefaultRealmService.java:115)    at org.wso2.carbon.user.core.internal.Activator.startDeploy(Activator.java:72)    at org.wso2.carbon.user.core.internal.BundleCheckActivator.start(BundleCheckActivator.java:61)    at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)    at java.security.AccessController.doPrivileged(Native Method)    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)    at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)    at org.eclipse.osgi.framework.internal.core.AbstractBundle.resume(AbstractBundle.java:390)    at org.eclipse.osgi.framework.internal.core.Framework.resumeBundle(Framework.java:1176)我的 log4jdbc 版本是 log4jdbc4-1.2.jar。任何幫助表示贊賞。提前致謝。http://msmshariq.blogspot.com/2015/03/troubleshooting-wso2-server-database.html