org.apache.tomcat.util.compat.JreCompat Maven / Gradle / Ivy
/*
* 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.tomcat.util.compat;
import java.lang.reflect.Field;
import org.apache.tomcat.util.res.StringManager;
/**
* This is the base implementation class for JRE compatibility and provides an
* implementation based on Java 17. Sub-classes may extend this class and provide
* alternative implementations for later JRE versions
*/
public class JreCompat {
private static final JreCompat instance;
private static final boolean graalAvailable;
private static final boolean jre19Available;
private static final boolean jre21Available;
private static final boolean jre22Available;
private static final StringManager sm = StringManager.getManager(JreCompat.class);
static {
boolean result = false;
try {
Class nativeImageClazz = Class.forName("org.graalvm.nativeimage.ImageInfo");
result = Boolean.TRUE.equals(nativeImageClazz.getMethod("inImageCode").invoke(null));
} catch (ClassNotFoundException e) {
// Must be Graal
} catch (ReflectiveOperationException | IllegalArgumentException e) {
// Should never happen
}
graalAvailable = result || System.getProperty("org.graalvm.nativeimage.imagecode") != null;
// This is Tomcat 11.0.x with a minimum Java version of Java 17.
// Look for the highest supported JVM first
if (Jre22Compat.isSupported()) {
instance = new Jre22Compat();
jre22Available = true;
jre21Available = true;
jre19Available = true;
} else if (Jre21Compat.isSupported()) {
instance = new Jre21Compat();
jre22Available = false;
jre21Available = true;
jre19Available = true;
} else if (Jre19Compat.isSupported()) {
instance = new Jre19Compat();
jre22Available = false;
jre21Available = false;
jre19Available = true;
} else {
instance = new JreCompat();
jre22Available = false;
jre21Available = false;
jre19Available = false;
}
}
public static JreCompat getInstance() {
return instance;
}
public static boolean isGraalAvailable() {
return graalAvailable;
}
public static boolean isJre19Available() {
return jre19Available;
}
public static boolean isJre21Available() {
return jre21Available;
}
public static boolean isJre22Available() {
return jre22Available;
}
// Java 17 implementations of Java 19 methods
/**
* Obtains the executor, if any, used to create the provided thread.
*
* @param thread The thread to examine
*
* @return The executor, if any, that created the provided thread
*
* @throws NoSuchFieldException
* If a field used via reflection to obtain the executor cannot
* be found
* @throws SecurityException
* If a security exception occurs while trying to identify the
* executor
* @throws IllegalArgumentException
* If the instance object does not match the class of the field
* when obtaining a field value via reflection
* @throws IllegalAccessException
* If a field is not accessible due to access restrictions
*/
public Object getExecutor(Thread thread)
throws NoSuchFieldException, SecurityException, IllegalArgumentException, IllegalAccessException {
Object result = null;
// Runnable wrapped by Thread
// "target" in Sun/Oracle JDK
// "runnable" in IBM JDK
// "action" in Apache Harmony
Object target = null;
for (String fieldName : new String[] { "target", "runnable", "action" }) {
try {
Field targetField = thread.getClass().getDeclaredField(fieldName);
targetField.setAccessible(true);
target = targetField.get(thread);
break;
} catch (NoSuchFieldException nfe) {
continue;
}
}
// "java.util.concurrent" code is in public domain,
// so all implementations are similar including our
// internal fork.
if (target != null && target.getClass().getCanonicalName() != null &&
(target.getClass().getCanonicalName().equals(
"org.apache.tomcat.util.threads.ThreadPoolExecutor.Worker") ||
target.getClass().getCanonicalName().equals(
"java.util.concurrent.ThreadPoolExecutor.Worker"))) {
Field executorField = target.getClass().getDeclaredField("this$0");
executorField.setAccessible(true);
result = executorField.get(target);
}
return result;
}
// Java 17 implementations of Java 21 methods
/**
* Create a thread builder for virtual threads using the given name to name the threads.
*
* @param name The base name for the threads
*
* @return The thread buidler for virtual threads
*/
public Object createVirtualThreadBuilder(String name) {
throw new UnsupportedOperationException(sm.getString("jreCompat.noVirtualThreads"));
}
/**
* Create a thread with the given thread builder and use it to execute the given runnable.
*
* @param threadBuilder The thread builder to use to create a thread
* @param command The command to run
*/
public void threadBuilderStart(Object threadBuilder, Runnable command) {
throw new UnsupportedOperationException(sm.getString("jreCompat.noVirtualThreads"));
}
}