com.ibm.fhir.audit.AuditLogServiceFactory Maven / Gradle / Ivy
/*
* (C) Copyright IBM Corp. 2016, 2020
*
* SPDX-License-Identifier: Apache-2.0
*/
package com.ibm.fhir.audit;
import java.util.logging.Logger;
import org.owasp.encoder.Encode;
import com.ibm.fhir.audit.configuration.ConfigurationTranslator;
import com.ibm.fhir.config.FHIRConfigHelper;
import com.ibm.fhir.config.FHIRConfiguration;
import com.ibm.fhir.config.PropertyGroup;
/**
* Instantiates and returns an implementation of the FHIR server audit log service.
*/
public class AuditLogServiceFactory {
private static final Logger log = java.util.logging.Logger.getLogger(AuditLogServiceFactory.class.getName());
private static final String CLASSNAME = AuditLogServiceFactory.class.getName();
private static final ConfigurationTranslator translator = new ConfigurationTranslator();
// To prevent java writing re-order issue of the Double check locking singleton, using volatile
// for the service instance. or we can use the Eager initialization pattern or
// inner static classes pattern for this singleton
private static volatile AuditLogService serviceInstance = null;
/**
* Returns the AuditLogService to be used by all FHIR server components.
* @return AuditLogService
* @throws AuditLoggingException
*/
public static AuditLogService getService() {
if (serviceInstance == null) {
createService();
}
return serviceInstance;
}
/**
* Creates and caches a singleton instance of an audit log service, based on audit log configuration settings.
*/
private static synchronized void createService() {
final String METHODNAME = "createService";
log.entering(CLASSNAME, METHODNAME);
final String NEWLINE = System.getProperty("line.separator");
String serviceClassName;
Class serviceClass;
StringBuilder errMsg;
PropertyGroup auditLogProperties;
if (serviceInstance == null) {
errMsg = new StringBuilder();
serviceClassName = FHIRConfigHelper.getStringProperty(FHIRConfiguration.PROPERTY_AUDIT_SERVICE_CLASS_NAME, null);
if (serviceClassName == null || serviceClassName.isEmpty()) {
errMsg.append("Audit log service class name not configured.");
} else {
serviceClassName = translator.remap(serviceClassName);
try {
serviceClass = Class.forName(serviceClassName);
if (AuditLogService.class.isAssignableFrom(serviceClass)) {
try {
serviceInstance = (AuditLogService)serviceClass.newInstance();
auditLogProperties = FHIRConfigHelper.getPropertyGroup(FHIRConfiguration.PROPERTY_AUDIT_SERVICE_PROPERTIES);
serviceInstance.initialize(auditLogProperties);
log.info("Successfully initialized audit log service: " + serviceClassName);
} catch(IllegalAccessException | InstantiationException e) {
errMsg.append("Could not instantiate " + serviceClassName + NEWLINE + e.toString());
} catch(Throwable e) {
errMsg.append("Failure initializing audit log service: " + serviceClassName + NEWLINE + e.toString());
}
} else {
errMsg.append("Audit log service class does not implement AuditLogService interface.");
}
} catch (ClassNotFoundException e) {
errMsg.append("Audit log service class name not found: " + serviceClassName);
}
}
if (errMsg.length() > 0) {
errMsg.append(" ").append("Audit logging is disabled.");
log.severe(Encode.forHtml(errMsg.toString()));
// Have to exit if fails to start audit
//serviceInstance = new DisabledAuditLogService();
System.exit(1);
}
}
log.exiting(CLASSNAME, METHODNAME);
}
/**
* Resets the singleton instance of the audit logger service object that is cached by this factory class,
* then creates, caches, and returns a new service object instance.
*
* @return AuditLogService - The newly cached audit log service object.
* @throws AuditLoggingException
*/
public static AuditLogService resetService() {
final String METHODNAME = "resetService";
log.entering(CLASSNAME, METHODNAME);
serviceInstance = null;
AuditLogService newService = getService();
log.exiting(CLASSNAME, METHODNAME);
return newService;
}
}