io.opentelemetry.instrumentation.test.utils.ClasspathUtils Maven / Gradle / Ivy
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/*
* Copyright The OpenTelemetry Authors
* SPDX-License-Identifier: Apache-2.0
*/
package io.opentelemetry.instrumentation.test.utils;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.net.URL;
import java.util.UUID;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
public final class ClasspathUtils {
public static byte[] convertToByteArray(InputStream resource) throws IOException {
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int bytesRead;
byte[] data = new byte[1024];
while ((bytesRead = resource.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, bytesRead);
}
buffer.flush();
return buffer.toByteArray();
}
public static byte[] convertToByteArray(Class clazz) throws IOException {
try (InputStream inputStream =
clazz.getClassLoader().getResourceAsStream(getResourceName(clazz.getName()))) {
return convertToByteArray(inputStream);
}
}
/**
* Create a temporary jar on the filesystem with the bytes of the given classes.
*
* The jar file will be removed when the jvm exits.
*
* @param loader class loader used to load bytes
* @param resourceNames names of resources to copy into the new jar
* @return the location of the newly created jar.
*/
public static URL createJarWithClasses(ClassLoader loader, String... resourceNames)
throws IOException {
File tmpJar = File.createTempFile(UUID.randomUUID() + "", ".jar");
tmpJar.deleteOnExit();
Manifest manifest = new Manifest();
JarOutputStream target = new JarOutputStream(new FileOutputStream(tmpJar), manifest);
for (String resourceName : resourceNames) {
try (InputStream is = loader.getResourceAsStream(resourceName)) {
addToJar(resourceName, convertToByteArray(is), target);
}
}
target.close();
return tmpJar.toURI().toURL();
}
/**
* Create a temporary jar on the filesystem with the bytes of the given classes.
*
*
The jar file will be removed when the jvm exits.
*
* @param classes classes to package into the jar.
* @return the location of the newly created jar.
*/
public static URL createJarWithClasses(Class... classes) throws IOException {
File tmpJar = File.createTempFile(UUID.randomUUID() + "", ".jar");
tmpJar.deleteOnExit();
Manifest manifest = new Manifest();
JarOutputStream target = new JarOutputStream(new FileOutputStream(tmpJar), manifest);
for (Class clazz : classes) {
addToJar(getResourceName(clazz.getName()), convertToByteArray(clazz), target);
}
target.close();
return tmpJar.toURI().toURL();
}
private static void addToJar(String resourceName, byte[] bytes, JarOutputStream jarOutputStream)
throws IOException {
JarEntry entry = new JarEntry(resourceName);
jarOutputStream.putNextEntry(entry);
jarOutputStream.write(bytes, 0, bytes.length);
jarOutputStream.closeEntry();
}
// Moved this to a java class because groovy was adding a hard ref to classLoader
public static boolean isClassLoaded(String className, ClassLoader classLoader) {
try {
Method findLoadedClassMethod =
ClassLoader.class.getDeclaredMethod("findLoadedClass", String.class);
try {
findLoadedClassMethod.setAccessible(true);
Class loadedClass = (Class) findLoadedClassMethod.invoke(classLoader, className);
return null != loadedClass && loadedClass.getClassLoader() == classLoader;
} catch (Exception e) {
throw new IllegalStateException(e);
} finally {
findLoadedClassMethod.setAccessible(false);
}
} catch (NoSuchMethodException e) {
throw new IllegalStateException(e);
}
}
/** com.foo.Bar to com/foo/Bar.class */
private static String getResourceName(String className) {
if (!className.endsWith(".class")) {
return className.replace('.', '/') + ".class";
} else {
return className;
}
}
private ClasspathUtils() {}
}