com.sun.star.lib.util.NativeLibraryLoader Maven / Gradle / Ivy
Show all versions of libreoffice Show documentation
/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
package com.sun.star.lib.util;
import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;
/**
* Helper functions to locate and load native files.
*
* The methods in this class are designed to find the requested resources in
* as many cases as possible. They search various places, roughly from most
* specific to most general. This works well if a component is known to bring
* with it a certain resource, and that resource has to be found. However, it
* might not work very well in cases where you want to check whether a
* component brings with it a certain resource or not: a similarly named
* resource from another component might be found by the eager search
* algorithm.
*/
public final class NativeLibraryLoader {
/**
* Load a system library, using a given class loader to locate the library.
*
* This is similar to System.loadLibrary
.
*
* @param loader a class loader; may be null.
* @param libname the library name; how this name is mapped to a system
* library name is system dependent.
*/
public static void loadLibrary(ClassLoader loader, String libname) {
String sysname = System.mapLibraryName(libname);
// At least Oracle's 1.7.0_51 now maps to .dylib rather than .jnilib:
if (System.getProperty("os.name").startsWith("Mac")
&& sysname.endsWith(".dylib"))
{
sysname
= sysname.substring(0, sysname.length() - "dylib".length())
+ "jnilib";
}
File path = getResource(loader, sysname);
if (path == null) {
// If the library cannot be found as a class loader resource, try
// the global System.loadLibrary as a last resort:
System.loadLibrary(libname);
} else {
System.load(path.getAbsolutePath());
}
}
/**
* Locate a system resource, using a given class loader.
*
* This is similar to ClassLoader.getResource
, but only works
* for local resources (local files), and adds additional functionality for
* URLClassLoaders
.
*
* @param loader a class loader; may be null.
* @param name a resource name (that is, the name of a file).
* @return a File locating the resource, or null if the resource was not
* found.
*/
public static File getResource(ClassLoader loader, String name) {
if (loader != null) {
File path = UrlToFileMapper.mapUrlToFile(loader.getResource(name));
if (path != null) {
return path;
}
}
// URLClassLoaders work on lists of URLs, which are typically URLs
// locating JAR files (scheme://auth/dir1/dir2/some.jar). The following
// code looks for resource name beside the JAR file
// (scheme://auth/dir1/dir2/name) and one directory up
// (scheme://auth/dir1/name). The second step is important in a typical
// OOo installation, where the JAR files are in the program/classes
// directory while the shared libraries are in the program directory.
if (!(loader instanceof URLClassLoader)) {
return null;
}
URL[] urls = ((URLClassLoader) loader).getURLs();
for (int i = 0; i < urls.length; ++i) {
File path = UrlToFileMapper.mapUrlToFile(urls[i]);
if (path != null) {
File dir = path.isDirectory() ? path : path.getParentFile();
if (dir != null) {
path = new File(dir, name);
if (path.exists()) {
return path;
}
dir = dir.getParentFile();
if (dir != null) {
path = new File(dir, name);
if (path.exists()) {
return path;
}
// On macOS, dir is now the Resources dir,
// we want to look in Frameworks
if (System.getProperty("os.name").startsWith("Mac")
&& dir.getName().equals("Resources")) {
dir = dir.getParentFile();
path = new File(dir, "Frameworks/" + name);
if (path.exists()) {
return path;
}
}
}
}
}
}
return null;
}
private NativeLibraryLoader() {} // do not instantiate
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */