org.apache.bookkeeper.common.util.nativeio.NativeUtils Maven / Gradle / Ivy
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* 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
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.bookkeeper.common.util.nativeio;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import lombok.NonNull;
/**
* Utility class to load jni library from inside a JAR.
*/
final class NativeUtils {
/**
* loads given library from the this jar. ie: this jar contains: /lib/pulsar-checksum.jnilib
*
* @param path
* : absolute path of the library in the jar
* if this jar contains: /lib/pulsar-checksum.jnilib then provide the same absolute path as input
* @throws Exception
*/
@SuppressFBWarnings(value = "OBL_UNSATISFIED_OBLIGATION", justification = "work around for java 9: https://github.com/spotbugs/spotbugs/issues/493")
static void loadLibraryFromJar(String path) throws Exception {
checkArgument(path.startsWith("/"), "absolute path must start with /");
String[] parts = path.split("/");
checkArgument(parts.length > 0, "absolute path must contain file name");
String filename = parts[parts.length - 1];
File dir = Files.createTempDirectory("native").toFile();
dir.deleteOnExit();
File temp = new File(dir, filename);
temp.deleteOnExit();
byte[] buffer = new byte[1024];
int read;
try (
InputStream input = NativeUtils.class.getResourceAsStream(path);
OutputStream out = new FileOutputStream(temp)) {
if (input == null) {
throw new FileNotFoundException("Couldn\'t find file into jar " + path);
}
while ((read = input.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
}
if (!temp.exists()) {
throw new FileNotFoundException("Failed to copy file from jar at " + temp.getAbsolutePath());
}
System.load(temp.getAbsolutePath());
}
public static void checkArgument(boolean expression, @NonNull Object errorMessage) {
if (errorMessage == null) {
throw new NullPointerException("errorMessage is marked non-null but is null");
}
if (!expression) {
throw new IllegalArgumentException(String.valueOf(errorMessage));
}
}
private NativeUtils() {
throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
}
}