001 /** 002 * Copyright (c) 2010 Yahoo! Inc. All rights reserved. 003 * Licensed under the Apache License, Version 2.0 (the "License"); 004 * you may not use this file except in compliance with the License. 005 * You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software 010 * distributed under the License is distributed on an "AS IS" BASIS, 011 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 * See the License for the specific language governing permissions and 013 * limitations under the License. See accompanying LICENSE file. 014 */ 015 package org.apache.oozie.util; 016 017 import org.apache.oozie.util.XLogStreamer; 018 019 import java.util.ArrayList; 020 import java.io.Writer; 021 import java.io.IOException; 022 import java.io.BufferedReader; 023 import java.io.InputStreamReader; 024 import java.io.InputStream; 025 026 /** 027 * Reads the input stream(log file) and applies the filters and writes it to output stream. The filtering will also 028 * consider the log messages spilling over multiline. 029 */ 030 public class XLogReader { 031 private BufferedReader logReader; 032 private Writer logWriter; 033 private boolean noFilter = false; 034 private XLogStreamer.Filter logFilter; 035 036 public XLogReader(InputStream logFileIS, XLogStreamer.Filter filter, Writer logWriter) { 037 logReader = new BufferedReader(new InputStreamReader(logFileIS)); 038 logFilter = filter; 039 this.logWriter = logWriter; 040 } 041 042 /** 043 * Processes the Given Log and writes the output after applying the filters. 044 * 045 * @throws IOException 046 */ 047 public void processLog() throws IOException { 048 String line = logReader.readLine(); 049 boolean patternMatched = false; 050 int lcnt = 0; 051 if (logFilter == null || !logFilter.isFilterPresent()) { 052 noFilter = true; 053 } 054 else { 055 logFilter.constructPattern(); 056 } 057 while (line != null) { 058 if (noFilter) { 059 logWriter.write(line + "\n"); 060 } 061 else { 062 ArrayList<String> logParts = logFilter.splitLogMessage(line); 063 if (logParts != null) { 064 patternMatched = logFilter.matches(logParts); 065 } 066 if (patternMatched) { 067 logWriter.write(line + "\n"); 068 } 069 } 070 lcnt++; 071 if (lcnt % 20 == 0) { 072 logWriter.flush(); 073 } 074 line = logReader.readLine(); 075 } 076 logWriter.flush(); 077 } 078 }