com.google.cloud.nativeimage.features.NativeImageUtils Maven / Gradle / Ivy
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/*
* Copyright 2022 Google LLC
*
* Licensed 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
*
* https://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 com.google.cloud.nativeimage.features;
import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.logging.Logger;
import org.graalvm.nativeimage.hosted.Feature.FeatureAccess;
import org.graalvm.nativeimage.hosted.RuntimeReflection;
/** Internal class offering helper methods for registering methods/classes for reflection. */
public class NativeImageUtils {
private static final Logger LOGGER = Logger.getLogger(NativeImageUtils.class.getName());
/** Returns the method of a class or fails if it is not present. */
public static Method getMethodOrFail(Class clazz, String methodName, Class... params) {
try {
return clazz.getDeclaredMethod(methodName, params);
} catch (NoSuchMethodException e) {
throw new RuntimeException(
"Failed to find method " + methodName + " for class " + clazz.getName(), e);
}
}
/** Registers a class for reflective construction via its default constructor. */
public static void registerForReflectiveInstantiation(FeatureAccess access, String className) {
Class clazz = access.findClassByName(className);
if (clazz != null) {
RuntimeReflection.register(clazz);
RuntimeReflection.registerForReflectiveInstantiation(clazz);
} else {
LOGGER.warning(
"Failed to find " + className + " on the classpath for reflective instantiation.");
}
}
/** Registers all constructors of a class for reflection. */
public static void registerConstructorsForReflection(FeatureAccess access, String name) {
Class clazz = access.findClassByName(name);
if (clazz != null) {
RuntimeReflection.register(clazz);
RuntimeReflection.register(clazz.getDeclaredConstructors());
} else {
LOGGER.warning("Failed to find " + name + " on the classpath for reflection.");
}
}
/** Registers an entire class for reflection use. */
public static void registerClassForReflection(FeatureAccess access, String name) {
Class clazz = access.findClassByName(name);
if (clazz != null) {
RuntimeReflection.register(clazz);
RuntimeReflection.register(clazz.getDeclaredConstructors());
RuntimeReflection.register(clazz.getDeclaredFields());
RuntimeReflection.register(clazz.getDeclaredMethods());
} else {
LOGGER.warning("Failed to find " + name + " on the classpath for reflection.");
}
}
/**
* Registers the transitive class hierarchy of the provided {@code className} for reflection.
*
* The transitive class hierarchy contains the class itself and its transitive set of
* *non-private* nested subclasses.
*/
public static void registerClassHierarchyForReflection(FeatureAccess access, String className) {
Class clazz = access.findClassByName(className);
if (clazz != null) {
registerClassForReflection(access, className);
for (Class nestedClass : clazz.getDeclaredClasses()) {
if (!Modifier.isPrivate(nestedClass.getModifiers())) {
registerClassHierarchyForReflection(access, nestedClass.getName());
}
}
} else {
LOGGER.warning("Failed to find " + className + " on the classpath for reflection.");
}
}
/** Registers a class for unsafe reflective field access. */
public static void registerForUnsafeFieldAccess(
FeatureAccess access, String className, String... fields) {
Class clazz = access.findClassByName(className);
if (clazz != null) {
RuntimeReflection.register(clazz);
for (String fieldName : fields) {
try {
RuntimeReflection.register(clazz.getDeclaredField(fieldName));
} catch (NoSuchFieldException ex) {
LOGGER.warning("Failed to register field " + fieldName + " for class " + className);
LOGGER.warning(ex.getMessage());
}
}
} else {
LOGGER.warning(
"Failed to find "
+ className
+ " on the classpath for unsafe fields access registration.");
}
}
/** Registers all the classes under the specified package for reflection. */
public static void registerPackageForReflection(FeatureAccess access, String packageName) {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
try {
String path = packageName.replace('.', '/');
Enumeration resources = classLoader.getResources(path);
while (resources.hasMoreElements()) {
URL url = resources.nextElement();
URLConnection connection = url.openConnection();
if (connection instanceof JarURLConnection) {
List classes = findClassesInJar((JarURLConnection) connection, packageName);
for (String className : classes) {
registerClassHierarchyForReflection(access, className);
}
}
}
} catch (IOException e) {
throw new RuntimeException("Failed to load classes under package name.", e);
}
}
private static List findClassesInJar(JarURLConnection urlConnection, String packageName)
throws IOException {
List result = new ArrayList<>();
final JarFile jarFile = urlConnection.getJarFile();
final Enumeration entries = jarFile.entries();
while (entries.hasMoreElements()) {
JarEntry entry = entries.nextElement();
String entryName = entry.getName();
if (entryName.endsWith(".class")) {
String javaClassName = entryName.replace(".class", "").replace('/', '.');
if (javaClassName.startsWith(packageName)) {
result.add(javaClassName);
}
}
}
return result;
}
}