001 package org.apache.fulcrum.yaafi.framework.util; 002 003 /* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022 import java.io.File; 023 import java.io.FileInputStream; 024 import java.io.IOException; 025 import java.io.InputStream; 026 027 import org.apache.avalon.framework.logger.Logger; 028 import org.apache.avalon.framework.logger.NullLogger; 029 030 /** 031 * Helper for locating a file name and returning an input stream. 032 * 033 * @author <a href="mailto:siegfried.goeschl@it20one.at">Siegfried Goeschl</a> 034 */ 035 036 public class InputStreamLocator 037 { 038 /** the root directory of our search */ 039 private File rootDir; 040 041 /** the logger to be used */ 042 private Logger logger; 043 044 /** 045 * Constructor 046 */ 047 public InputStreamLocator() 048 { 049 this.rootDir = new File( new File("").getAbsolutePath() ); 050 this.logger = new NullLogger(); 051 } 052 053 /** 054 * Constructor 055 * 056 * @param rootDir the root directory to start the search */ 057 public InputStreamLocator( File rootDir ) 058 { 059 this( rootDir, new NullLogger() ); 060 } 061 062 /** 063 * Constructor 064 * 065 * @param rootDir the root directory to start the search 066 * @param logger the logger to be used 067 */ 068 public InputStreamLocator( File rootDir, Logger logger ) 069 { 070 this.rootDir = rootDir; 071 this.logger = logger; 072 } 073 074 /** 075 * Locate the file with the given position using the following steps 076 * 077 * @param location the location of the source to be loaded 078 */ 079 public InputStream locate( String location ) throws IOException 080 { 081 if( ( location == null ) || ( location.length() == 0 ) ) 082 { 083 return null; 084 } 085 086 String baseName = null; 087 File file = null; 088 InputStream is = null; 089 090 // try to load a relative location with the given root dir 091 // e.g. "componentRoles.xml" located in the current working directory 092 093 if( is == null ) 094 { 095 file = new File( this.rootDir, location ); 096 097 this.getLogger().debug("Looking for " + location + " in the root directory"); 098 099 if( file.exists() ) 100 { 101 is = new FileInputStream( file ); 102 this.getLogger().debug("Found " + location + " as " + file.getAbsolutePath() ); 103 } 104 } 105 106 // try to load an absolute location as file 107 // e.g. "/foo/componentRoles.xml" from the root of the file system 108 109 if( is == null ) 110 { 111 file = new File( location ); 112 113 this.getLogger().debug("Looking for " + location + " as absolute file location"); 114 115 if( file.isAbsolute() && file.exists() ) 116 { 117 is = new FileInputStream( file ); 118 this.getLogger().debug("Found " + location + " as " + file.getAbsolutePath() ); 119 } 120 } 121 122 // try to load an absolute location through the classpath 123 // e.g. "/componentRoles.xml" located in the classpath 124 125 if( ( is == null ) && ( location.startsWith( "/" ) == true ) ) 126 { 127 this.getLogger().debug("Looking for " + location + " using the class loader"); 128 is = getClass().getResourceAsStream( location ); 129 130 if( is != null ) 131 { 132 this.getLogger().debug("Successfully located " + location); 133 } 134 } 135 136 // try to load the last part of the file name using the classloader 137 // e.g. "conf/componentRoles.xml" as "/componentRoles.xml" located in 138 // the classpath. 139 140 if( ( is == null ) && ( location.startsWith( "/" ) == false ) ) 141 { 142 baseName = '/' + new File(location).getName(); 143 this.getLogger().debug("Looking for " + baseName + " using the class loader"); 144 is = getClass().getResourceAsStream( baseName ); 145 146 if( is != null ) 147 { 148 this.getLogger().debug("Successfully located " + baseName); 149 } 150 } 151 152 if( is == null ) 153 { 154 this.getLogger().warn("Unable to find any resource with the name '" + location + "'"); 155 } 156 157 return is; 158 } 159 160 /** 161 * @return Returns the logger. 162 */ 163 protected Logger getLogger() 164 { 165 return logger; 166 } 167 168 /** 169 * @return Returns the rootDir. 170 */ 171 protected File getRootDir() 172 { 173 return rootDir; 174 } 175 176 177 }