jurt/com/sun/star/lib/util/NativeLibraryLoader.java

   1 /* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 package com.sun.star.lib.util;
  20
  21 import java.io.File;
  22 import java.net.URL;
  23 import java.net.URLClassLoader;
  24
  25 /**
  26  * Helper functions to locate and load native files.
  27  *
  28  * <p>The methods in this class are designed to find the requested resources in
  29  * as many cases as possible.  They search various places, roughly from most
  30  * specific to most general.  This works well if a component is known to bring
  31  * with it a certain resource, and that resource has to be found.  However, it
  32  * might not work very well in cases where you want to check whether a
  33  * component brings with it a certain resource or not: a similarly named
  34  * resource from another component might be found by the eager search
  35  * algorithm.</p>
  36  */
  37 public final class NativeLibraryLoader {
  38     /**
  39      * Load a system library, using a given class loader to locate the library.
  40      *
  41      * <p>This is similar to <code>System.loadLibrary</code>.</p>
  42      *
  43      * @param loader a class loader; may be null.
  44      * @param libname the library name; how this name is mapped to a system
  45      * library name is system dependent.
  46      */
  47     public static void loadLibrary(ClassLoader loader, String libname) {
  48         String sysname = System.mapLibraryName(libname);
  49         // At least Oracle's 1.7.0_51 now maps to .dylib rather than .jnilib:
  50         if (System.getProperty("os.name").startsWith("Mac")
  51             && sysname.endsWith(".dylib"))
  52         {
  53             sysname
  54                 = sysname.substring(0, sysname.length() - "dylib".length())
  55                 + "jnilib";
  56         }
  57         File path = getResource(loader, sysname);
  58         if (path == null) {
  59             // If the library cannot be found as a class loader resource, try
  60             // the global System.loadLibrary as a last resort:
  61             System.loadLibrary(libname);
  62         } else {
  63             System.load(path.getAbsolutePath());
  64         }
  65     }
  66
  67     /**
  68      * Locate a system resource, using a given class loader.
  69      *
  70      * <p>This is similar to <code>ClassLoader.getResource</code>, but only works
  71      * for local resources (local files), and adds additional functionality for
  72      * <code>URLClassLoaders</code>.</p>
  73      *
  74      * @param loader a class loader; may be null.
  75      * @param name a resource name (that is, the name of a file).
  76      * @return a File locating the resource, or null if the resource was not
  77      * found.
  78      */
  79     public static File getResource(ClassLoader loader, String name) {
  80         if (loader != null) {
  81             File path = UrlToFileMapper.mapUrlToFile(loader.getResource(name));
  82             if (path != null) {
  83                 return path;
  84             }
  85         }
  86         // URLClassLoaders work on lists of URLs, which are typically URLs
  87         // locating JAR files (scheme://auth/dir1/dir2/some.jar).  The following
  88         // code looks for resource name beside the JAR file
  89         // (scheme://auth/dir1/dir2/name) and one directory up
  90         // (scheme://auth/dir1/name).  The second step is important in a typical
  91         // OOo installation, where the JAR files are in the program/classes
  92         // directory while the shared libraries are in the program directory.
  93         if (!(loader instanceof URLClassLoader)) {
  94             return null;
  95         }
  96         URL[] urls = ((URLClassLoader) loader).getURLs();
  97         for (int i = 0; i < urls.length; ++i) {
  98             File path = UrlToFileMapper.mapUrlToFile(urls[i]);
  99             if (path != null) {
 100                 File dir = path.isDirectory() ? path : path.getParentFile();
 101                 if (dir != null) {
 102                     path = new File(dir, name);
 103                     if (path.exists()) {
 104                         return path;
 105                     }
 106                     dir = dir.getParentFile();
 107                     if (dir != null) {
 108                         path = new File(dir, name);
 109                         if (path.exists()) {
 110                             return path;
 111                         }
 112                         // On macOS, dir is now the Resources dir,
 113                         // we want to look in Frameworks
 114                         if (System.getProperty("os.name").startsWith("Mac")
 115                             && dir.getName().equals("Resources")) {
 116                             dir = dir.getParentFile();
 117                             path = new File(dir, "Frameworks/" + name);
 118                             if (path.exists()) {
 119                                 return path;
 120                             }
 121                         }
 122                     }
 123                 }
 124             }
 125         }
 126         return null;
 127     }
 128
 129     private NativeLibraryLoader() {} // do not instantiate
 130 }
 131
 132 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */