| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.io.CPFile |
| 4 | |
| 5 | Copyright 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.io; |
| 22 | |
| 23 | import org.apache.derby.io.StorageFile; |
| 24 | |
| 25 | import java.io.InputStream; |
| 26 | |
| 27 | import java.io.FileNotFoundException; |
| 28 | import java.net.MalformedURLException; |
| 29 | import java.net.URL; |
| 30 | |
| 31 | /** |
| 32 | * This class provides a class path based implementation of the StorageFile interface. It is used by the |
| 33 | * database engine to access persistent data and transaction logs under the classpath subsubprotocol. |
| 34 | */ |
| 35 | class CPFile extends InputStreamFile |
| 36 | { |
| 37 | |
| 38 | private final CPStorageFactory storageFactory; |
| 39 | |
| 40 | CPFile( CPStorageFactory storageFactory, String path) |
| 41 | { |
| 42 | super( storageFactory, path); |
| 43 | this.storageFactory = storageFactory; |
| 44 | } |
| 45 | |
| 46 | CPFile( CPStorageFactory storageFactory, String parent, String name) |
| 47 | { |
| 48 | super( storageFactory, parent, name); |
| 49 | this.storageFactory = storageFactory; |
| 50 | } |
| 51 | |
| 52 | CPFile( CPFile dir, String name) |
| 53 | { |
| 54 | super( dir,name); |
| 55 | this.storageFactory = dir.storageFactory; |
| 56 | } |
| 57 | |
| 58 | private CPFile( CPStorageFactory storageFactory, String child, int pathLen) |
| 59 | { |
| 60 | super( storageFactory, child, pathLen); |
| 61 | this.storageFactory = storageFactory; |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Tests whether the named file exists. |
| 66 | * |
| 67 | * @return <b>true</b> if the named file exists, <b>false</b> if not. |
| 68 | */ |
| 69 | public boolean exists() |
| 70 | { |
| 71 | return getURL() != null; |
| 72 | } // end of exists |
| 73 | |
| 74 | /** |
| 75 | * Get the parent of this file. |
| 76 | * |
| 77 | * @param pathLen the length of the parent's path name. |
| 78 | */ |
| 79 | StorageFile getParentDir( int pathLen) |
| 80 | { |
| 81 | return new CPFile( storageFactory, path, pathLen); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Creates an input stream from a file name. |
| 86 | * |
| 87 | * @return an input stream suitable for reading from the file. |
| 88 | * |
| 89 | * @exception FileNotFoundException if the file is not found. |
| 90 | */ |
| 91 | public InputStream getInputStream( ) throws FileNotFoundException |
| 92 | { |
| 93 | //System.out.println("HERE FOR " + toString()); |
| 94 | InputStream is = null; |
| 95 | ClassLoader cl = Thread.currentThread().getContextClassLoader(); |
| 96 | if (cl != null) |
| 97 | is = cl.getResourceAsStream(path); |
| 98 | |
| 99 | // don't assume the context class loader is tied |
| 100 | // into the class loader that loaded this class. |
| 101 | if (is == null) |
| 102 | { |
| 103 | cl = getClass().getClassLoader(); |
| 104 | // Javadoc indicates implementations can use |
| 105 | // null as a return from Class.getClassLoader() |
| 106 | // to indicate the system/bootstrap classloader. |
| 107 | if (cl != null) |
| 108 | is = cl.getResourceAsStream(path); |
| 109 | else |
| 110 | is = ClassLoader.getSystemResourceAsStream(path); |
| 111 | } |
| 112 | |
| 113 | if (is == null) |
| 114 | throw new FileNotFoundException(toString()); |
| 115 | return is; |
| 116 | |
| 117 | } // end of getInputStream |
| 118 | |
| 119 | /** |
| 120 | * Return a URL for this file (resource). |
| 121 | * |
| 122 | * @see org.apache.derby.io.StorageFile#getURL() |
| 123 | */ |
| 124 | public URL getURL() { |
| 125 | |
| 126 | ClassLoader cl = Thread.currentThread().getContextClassLoader(); |
| 127 | URL myURL; |
| 128 | if (cl != null) { |
| 129 | myURL = cl.getResource(path); |
| 130 | if (myURL != null) |
| 131 | return myURL; |
| 132 | } |
| 133 | |
| 134 | // don't assume the context class loader is tied |
| 135 | // into the class loader that loaded this class. |
| 136 | cl = getClass().getClassLoader(); |
| 137 | // Javadoc indicates implementations can use |
| 138 | // null as a return from Class.getClassLoader() |
| 139 | // to indicate the system/bootstrap classloader. |
| 140 | if (cl != null) { |
| 141 | return cl.getResource(path); |
| 142 | } else { |
| 143 | return ClassLoader.getSystemResource(path); |
| 144 | } |
| 145 | } |
| 146 | } |