1 /************************************************************************* 2 * 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * Copyright 2000, 2010 Oracle and/or its affiliates. 6 * 7 * OpenOffice.org - a multi-platform office productivity suite 8 * 9 * This file is part of OpenOffice.org. 10 * 11 * OpenOffice.org is free software: you can redistribute it and/or modify 12 * it under the terms of the GNU Lesser General Public License version 3 13 * only, as published by the Free Software Foundation. 14 * 15 * OpenOffice.org is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License version 3 for more details 19 * (a copy is included in the LICENSE file that accompanied this code). 20 * 21 * You should have received a copy of the GNU Lesser General Public License 22 * version 3 along with OpenOffice.org. If not, see 23 * <http://www.openoffice.org/license.html> 24 * for a copy of the LGPLv3 License. 25 * 26 ************************************************************************/ 27 package com.sun.star.lib.util; 28 29 import java.io.File; 30 import java.net.URL; 31 import java.net.URLClassLoader; 32 33 /** Helper functions to locate and load native files. 34 35 The methods in this class are designed to find the requested resources in as 36 many cases as possible. They search various places, roughly from most 37 specific to most general. This works well if a component is known to bring 38 with it a certain resource, and that resource has to be found. However, it 39 might not work very well in cases where you want to check whether a 40 component brings with it a certain resource or not: a similarly named 41 resource from another component might be found by the eager search 42 algorithm. 43 */ 44 public final class NativeLibraryLoader { 45 /** Load a system library, using a given class loader to locate the library. 46 47 This is similar to System.loadLibrary. 48 49 @param loader a class loader; may be null 50 51 @param libname the library name; how this name is mapped to a system 52 library name is system dependent 53 */ 54 public static void loadLibrary(ClassLoader loader, String libname) { 55 File path = getResource(loader, System.mapLibraryName(libname)); 56 if (path == null) { 57 // If the library cannot be found as a class loader resource, try 58 // the global System.loadLibrary as a last resort: 59 System.loadLibrary(libname); 60 } else { 61 System.load(path.getAbsolutePath()); 62 } 63 } 64 65 /** Locate a system resource, using a given class loader. 66 67 This is similar to ClassLoader.getResource, but only works for local 68 resources (local files), and adds additional functionality for 69 URLClassLoaders. 70 71 @param loader a class loader; may be null 72 73 @param name a resource name (that is, the name of a file) 74 75 @return a File locating the resource, or null if the resource was not 76 found 77 */ 78 public static File getResource(ClassLoader loader, String name) { 79 if (loader != null) { 80 File path = UrlToFileMapper.mapUrlToFile(loader.getResource(name)); 81 if (path != null) { 82 return path; 83 } 84 } 85 // URLClassLoaders work on lists of URLs, which are typically URLs 86 // locating JAR files (scheme://auth/dir1/dir2/some.jar). The following 87 // code looks for resource name beside the JAR file 88 // (scheme://auth/dir1/dir2/name) and one directory up 89 // (scheme://auth/dir1/name). The second step is important in a typical 90 // OOo installation, where the JAR files are in the program/classes 91 // directory while the shared libraries are in the program directory. 92 if (loader instanceof URLClassLoader) { 93 URL[] urls = ((URLClassLoader) loader).getURLs(); 94 for (int i = 0; i < urls.length; ++i) { 95 File path = UrlToFileMapper.mapUrlToFile(urls[i]); 96 if (path != null) { 97 File dir = path.isDirectory() ? path : path.getParentFile(); 98 if (dir != null) { 99 path = new File(dir, name); 100 if (path.exists()) { 101 return path; 102 } 103 dir = dir.getParentFile(); 104 if (dir != null) { 105 path = new File(dir, name); 106 if (path.exists()) { 107 return path; 108 } 109 } 110 } 111 } 112 } 113 } 114 return null; 115 } 116 117 private NativeLibraryLoader() {} // do not instantiate 118 } 119