stringmatchfilter.java

apache的log4j源码

/*
 * 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.varia;

import org.apache.log4j.spi.Filter;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.helpers.OptionConverter;

/**
 * This is a very simple filter based on string matching.
 *
 * <p>The filter admits two options <b>StringToMatch</b> and
 * <b>AcceptOnMatch</b>. If there is a match between the value of the
 * StringToMatch option and the message of the {@link org.apache.log4j.spi.LoggingEvent},
 * then the {@link #decide(LoggingEvent)} method returns {@link org.apache.log4j.spi.Filter#ACCEPT} if
 * the <b>AcceptOnMatch</b> option value is true, if it is false then
 * {@link org.apache.log4j.spi.Filter#DENY} is returned. If there is no match, {@link
 * org.apache.log4j.spi.Filter#NEUTRAL} is returned.
 *
 * @author Ceki G&uuml;lc&uuml;
 * @since 0.9.0 
 */
public class StringMatchFilter extends Filter {
  
  /**
     @deprecated Options are now handled using the JavaBeans paradigm.
     This constant is not longer needed and will be removed in the
     <em>near</em> term.
   */
  public static final String STRING_TO_MATCH_OPTION = "StringToMatch";

  /**
     @deprecated Options are now handled using the JavaBeans paradigm.
     This constant is not longer needed and will be removed in the
     <em>near</em> term.
   */
  public static final String ACCEPT_ON_MATCH_OPTION = "AcceptOnMatch";
  
  boolean acceptOnMatch = true;
  String stringToMatch;
  
  /**
     @deprecated We now use JavaBeans introspection to configure
     components. Options strings are no longer needed.
  */
  public
  String[] getOptionStrings() {
    return new String[] {STRING_TO_MATCH_OPTION, ACCEPT_ON_MATCH_OPTION};
  }

  /**
     @deprecated Use the setter method for the option directly instead
     of the generic <code>setOption</code> method. 
  */
  public
  void setOption(String key, String value) { 
    
    if(key.equalsIgnoreCase(STRING_TO_MATCH_OPTION)) {
      stringToMatch = value;
    } else if (key.equalsIgnoreCase(ACCEPT_ON_MATCH_OPTION)) {
      acceptOnMatch = OptionConverter.toBoolean(value, acceptOnMatch);
    }
  }
  
  public
  void setStringToMatch(String s) {
    stringToMatch = s;
  }
  
  public
  String getStringToMatch() {
    return stringToMatch;
  }
  
  public
  void setAcceptOnMatch(boolean acceptOnMatch) {
    this.acceptOnMatch = acceptOnMatch;
  }
  
  public
  boolean getAcceptOnMatch() {
    return acceptOnMatch;
  }

  /**
     Returns {@link Filter#NEUTRAL} is there is no string match.
   */
  public
  int decide(LoggingEvent event) {
    String msg = event.getRenderedMessage();

    if(msg == null ||  stringToMatch == null)
      return Filter.NEUTRAL;
    

    if( msg.indexOf(stringToMatch) == -1 ) {
      return Filter.NEUTRAL;
    } else { // we've got a match
      if(acceptOnMatch) {
	return Filter.ACCEPT;
      } else {
	return Filter.DENY;
      }
    }
  }
}