/*
* 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.util;
/**
* This class switches MDC values into the order
* (unreasonably) expected by the witness files.
*/
public class MDCOrderFilter implements Filter {
/**
* Unexpected orders of keys.
* Note expected values are "va-one-one" and "va-one-two".
*/
private static final String[] patterns =
new String[] {
"{key2,va12}{key1,va11}",
"{key2,value2}{key1,value1}"
};
/**
* Replacement values.
*/
private static final String[] replacements =
new String[] {
"{key1,va11}{key2,va12}",
"{key1,value1}{key2,value2}"
};
/**
* Switch order of MDC keys when not in expected order.
*/
public String filter(final String in) {
if (in == null) {
return null;
}
for(int i = 0; i < patterns.length; i++) {
int ipos = in.indexOf(patterns[i]);
if (ipos >= 1) {
return in.substring(0, ipos)
+ replacements[i]
+ in.substring(ipos + patterns[i].length());
}
}
return in;
}
}