org.apache.log4j.AppenderSkeleton Maven / Gradle / Ivy

/*
 * 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;

import org.apache.log4j.spi.ErrorHandler;
import org.apache.log4j.spi.Filter;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.spi.OptionHandler;


/** 
 * Abstract superclass of the other appenders in the package.
 *  
 *  This class provides the code for common functionality, such as
 *  support for threshold filtering and support for general filters.
 *
 * @since 0.8.1
 * @author Ceki Gülcü 
 * */
public abstract class AppenderSkeleton implements Appender, OptionHandler {

    /**
     * Create new instance.
     */
    public AppenderSkeleton() {
    }

  /**
     Derived appenders should override this method if option structure
     requires it.  */
  public
  void activateOptions() {
  }


  /**
     Add a filter to end of the filter list.

     @since 0.9.0
   */
  public
  void addFilter(Filter newFilter) {
  }

  /**
     Clear the filters chain.
     
     @since 0.9.0 */
  public
  void clearFilters() {
  }

  /**
     Finalize this appender by calling the derived class'
     close method.

     @since 0.8.4 */
  public
  void finalize() {
  }


  /** 
      Return the currently set {@link ErrorHandler} for this
      Appender.  

      @since 0.9.0 */
  public
  ErrorHandler getErrorHandler() {
      return null;
  }


  /**
     Returns the head Filter.
     
     @since 1.1
  */
  public
  Filter getFilter() {
      return null;
  }

  /** 
      Return the first filter in the filter chain for this
      Appender. The return value may be null if no is
      filter is set.
      
  */
  public
  final
  Filter getFirstFilter() {
    return null;
  }

  /**
     Returns the layout of this appender. The value may be null.
  */
  public
  Layout getLayout() {
    return null;
  }


  /**
     Returns the name of this appender.
     @return name, may be null.
   */
  public
  final
  String getName() {
    return null;
  }

  /**
     Returns this appenders threshold level. See the {@link
     #setThreshold} method for the meaning of this option.
     
     @since 1.1 */
  public
  Priority getThreshold() {
    return null;
  }


  /**
     Check whether the message level is below the appender's
     threshold. If there is no threshold set, then the return value is
     always true.

  */
  public
  boolean isAsSevereAsThreshold(Priority priority) {
    return false;
  }


  /**
    * This method performs threshold checks and invokes filters before
    * delegating actual logging to the subclasses specific {@link
    * AppenderSkeleton#append} method.
    * */
  public
  synchronized 
  void doAppend(LoggingEvent event) {
  }

  /** 
      Set the {@link ErrorHandler} for this Appender.
      @since 0.9.0
  */
  public
  synchronized
  void setErrorHandler(ErrorHandler eh) {
  }

  /**
     Set the layout for this appender. Note that some appenders have
     their own (fixed) layouts or do not use one. For example, the
     {@link org.apache.log4j.net.SocketAppender} ignores the layout set
     here. 
  */
  public
  void setLayout(Layout layout) {
  }

  
  /**
     Set the name of this Appender.
   */
  public
  void setName(String name) {
  }


  /**
     Set the threshold level. All log events with lower level
     than the threshold level are ignored by the appender.
     
     In configuration files this option is specified by setting the
     value of the Threshold option to a level
     string, such as "DEBUG", "INFO" and so on.
     
     @since 0.8.3 */
  public
  void setThreshold(Priority threshold) {
  }
}