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Adam Heinrich
2015-06-14 10:04:53 +02:00
commit 03f81e780d
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LICENSE Normal file
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The MIT License (MIT)
Copyright (c) 2012 Adam Heinrich <adam@adamh.cz>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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/*
* Class NativeUtils is published under the The MIT License:
*
* Copyright (c) 2012 Adam Heinrich <adam@adamh.cz>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package cz.adamh.utils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* A simple library class which helps with loading dynamic libraries stored in the
* JAR archive. These libraries usualy contain implementation of some methods in
* native code (using JNI - Java Native Interface).
*
* @see http://adamheinrich.com/blog/2012/how-to-load-native-jni-library-from-jar
* @see https://github.com/adamheinrich/native-utils
*
*/
public class NativeUtils {
/**
* Private constructor - this class will never be instanced
*/
private NativeUtils() {
}
/**
* Loads library from current JAR archive
*
* The file from JAR is copied into system temporary directory and then loaded. The temporary file is deleted after exiting.
* Method uses String as filename because the pathname is "abstract", not system-dependent.
*
* @param filename The filename inside JAR as absolute path (beginning with '/'), e.g. /package/File.ext
* @throws IOException If temporary file creation or read/write operation fails
* @throws IllegalArgumentException If source file (param path) does not exist
* @throws IllegalArgumentException If the path is not absolute or if the filename is shorter than three characters (restriction of {@see File#createTempFile(java.lang.String, java.lang.String)}).
*/
public static void loadLibraryFromJar(String path) throws IOException {
if (!path.startsWith("/")) {
throw new IllegalArgumentException("The path has to be absolute (start with '/').");
}
// Obtain filename from path
String[] parts = path.split("/");
String filename = (parts.length &gt; 1) ? parts[parts.length - 1] : null;
// Split filename to prexif and suffix (extension)
String prefix = "";
String suffix = null;
if (filename != null) {
parts = filename.split("\\.", 2);
prefix = parts[0];
suffix = (parts.length &gt; 1) ? "."+parts[parts.length - 1] : null; // Thanks, davs! :-)
}
// Check if the filename is okay
if (filename == null || prefix.length() &lt; 3) {
throw new IllegalArgumentException("The filename has to be at least 3 characters long.");
}
// Prepare temporary file
File temp = File.createTempFile(prefix, suffix);
temp.deleteOnExit();
if (!temp.exists()) {
throw new FileNotFoundException("File " + temp.getAbsolutePath() + " does not exist.");
}
// Prepare buffer for data copying
byte[] buffer = new byte[1024];
int readBytes;
// Open and check input stream
InputStream is = NativeUtils.class.getResourceAsStream(path);
if (is == null) {
throw new FileNotFoundException("File " + path + " was not found inside JAR.");
}
// Open output stream and copy data between source file in JAR and the temporary file
OutputStream os = new FileOutputStream(temp);
try {
while ((readBytes = is.read(buffer)) != -1) {
os.write(buffer, 0, readBytes);
}
} finally {
// If read/write fails, close streams safely before throwing an exception
os.close();
is.close();
}
// Finally, load the library
System.load(temp.getAbsolutePath());
}
}