001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package org.apache.commons.pipeline.stage; 019 020 import org.apache.commons.pipeline.StageException; 021 import org.apache.commons.pipeline.stage.BaseStage; 022 import java.util.Queue; 023 import org.apache.commons.logging.Log; 024 import org.apache.commons.logging.LogFactory; 025 026 027 /** 028 * A do-nothing implementation of Stage that simply logs the state of processing. 029 * and each object seen by its {@link #process(Object)} method. 030 * Useful for debugging purposes. 031 */ 032 public class LogStage extends BaseStage { 033 private Log log = LogFactory.getLog(LogStage.class); 034 035 /** 036 * Creates a new LogStage. 037 */ 038 public LogStage() { 039 } 040 041 /** 042 * Logs the point at which preprocessing runs. 043 */ 044 public void preprocess() throws StageException { 045 super.preprocess(); 046 log.info("Stage " + this.getClass().getName() + " preprocessing."); 047 } 048 049 /** 050 * Logs the current state of an object on the queue and passes the 051 * object unchanged to the next stage in the pipeline. 052 */ 053 public void process(Object obj) throws StageException { 054 log.info("Processing object " + obj); 055 this.emit(obj); 056 } 057 058 /** 059 * Logs tht point at which postprocessing runs 060 */ 061 public void postprocess() throws StageException { 062 log.info("Stage " + this.getClass().getName() + " postprocessing."); 063 } 064 065 /** 066 * Logs the point at which stage resources are released. 067 */ 068 public void release() { 069 log.info("Stage " + this.getClass().getName() + " released."); 070 } 071 072 /** 073 * Sets the logger. 074 */ 075 public synchronized void setLog(Log log) { 076 this.log = log; 077 } 078 079 /** 080 * Sets the logger based upon the log name. 081 */ 082 public synchronized void setLog(String logName) { 083 this.log = LogFactory.getLog(logName); 084 } 085 086 /** 087 * Sets the logger based upon the specified class. 088 */ 089 public synchronized void setLog(Class clazz) { 090 this.log = LogFactory.getLog(clazz); 091 } 092 }