| /** |
| * 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.hadoop.hdfs.server.namenode; |
| |
| import java.util.regex.Pattern; |
| |
| import org.apache.log4j.AppenderSkeleton; |
| import org.apache.log4j.spi.LoggingEvent; |
| |
| /** |
| * An appender that matches logged messages against the given |
| * regular expression. |
| */ |
| public class PatternMatchingAppender extends AppenderSkeleton { |
| private final Pattern pattern; |
| private volatile boolean matched; |
| |
| public PatternMatchingAppender() { |
| this.pattern = Pattern.compile("^.*FakeMetric.*$"); |
| this.matched = false; |
| } |
| |
| public boolean isMatched() { |
| return matched; |
| } |
| |
| @Override |
| protected void append(LoggingEvent event) { |
| if (pattern.matcher(event.getMessage().toString()).matches()) { |
| matched = true; |
| } |
| } |
| |
| @Override |
| public void close() { |
| } |
| |
| @Override |
| public boolean requiresLayout() { |
| return false; |
| } |
| } |