/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements.  See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License.  You may obtain a copy of the License at *  *      http://www.apache.org/licenses/LICENSE-2.0 *  * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.log4j.jmx;//import java.lang.reflect.Constructor;import java.util.Iterator;import javax.management.DynamicMBean;import javax.management.AttributeList;import javax.management.Attribute;import javax.management.RuntimeOperationsException;import javax.management.MBeanRegistration;import javax.management.MBeanServer;import javax.management.ObjectName;import org.apache.log4j.Logger;public abstract class AbstractDynamicMBean implements DynamicMBean,                                                      MBeanRegistration {  String dClassName;  MBeanServer server;  /**   * Enables the to get the values of several attributes of the Dynamic MBean.   */  public  AttributeList getAttributes(String[] attributeNames) {    // Check attributeNames is not null to avoid NullPointerException later on    if (attributeNames == null) {      throw new RuntimeOperationsException(			   new IllegalArgumentException("attributeNames[] cannot be null"),			   "Cannot invoke a getter of " + dClassName);    }    AttributeList resultList = new AttributeList();    // if attributeNames is empty, return an empty result list    if (attributeNames.length == 0)      return resultList;    // build the result attribute list    for (int i=0 ; i<attributeNames.length ; i++){      try {	Object value = getAttribute((String) attributeNames[i]);	resultList.add(new Attribute(attributeNames[i],value));      } catch (Exception e) {	e.printStackTrace();      }    }    return(resultList);  }  /**   * Sets the values of several attributes of the Dynamic MBean, and returns the   * list of attributes that have been set.   */  public AttributeList setAttributes(AttributeList attributes) {    // Check attributes is not null to avoid NullPointerException later on    if (attributes == null) {      throw new RuntimeOperationsException(                    new IllegalArgumentException("AttributeList attributes cannot be null"),		    "Cannot invoke a setter of " + dClassName);    }    AttributeList resultList = new AttributeList();    // if attributeNames is empty, nothing more to do    if (attributes.isEmpty())      return resultList;    // for each attribute, try to set it and add to the result list if successfull    for (Iterator i = attributes.iterator(); i.hasNext();) {      Attribute attr = (Attribute) i.next();      try {	setAttribute(attr);	String name = attr.getName();	Object value = getAttribute(name);	resultList.add(new Attribute(name,value));      } catch(Exception e) {	e.printStackTrace();      }    }    return(resultList);  }  protected  abstract  Logger getLogger();  public  void postDeregister() {    getLogger().debug("postDeregister is called.");  }  public  void postRegister(java.lang.Boolean registrationDone) {  }  public  void preDeregister() {    getLogger().debug("preDeregister called.");  }  public  ObjectName preRegister(MBeanServer server, ObjectName name) {    getLogger().debug("preRegister called. Server="+server+ ", name="+name);    this.server = server;    return name;  }}