/*
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 *  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
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package org.apache.tomcat.util.compat;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLConnection;
import java.util.Deque;
import java.util.jar.JarFile;

import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLParameters;

import org.apache.tomcat.util.res.StringManager;

This is the base implementation class for JRE compatibility and provides an implementation based on Java 8. Sub-classes may extend this class and provide alternative implementations for later JRE versions
/** * This is the base implementation class for JRE compatibility and provides an * implementation based on Java 8. Sub-classes may extend this class and provide * alternative implementations for later JRE versions */
public class JreCompat { private static final int RUNTIME_MAJOR_VERSION = 8; private static final JreCompat instance; private static final boolean graalAvailable; private static final boolean jre11Available; private static final boolean jre9Available; private static final StringManager sm = StringManager.getManager(JreCompat.class); protected static final Method setApplicationProtocolsMethod; protected static final Method getApplicationProtocolMethod; static { // This is Tomcat 10 with a minimum Java version of Java 8. // Look for the highest supported JVM first if (GraalCompat.isSupported()) { instance = new GraalCompat(); graalAvailable = true; jre9Available = Jre9Compat.isSupported(); } else if (Jre9Compat.isSupported()) { instance = new Jre9Compat(); graalAvailable = false; jre9Available = true; } else { instance = new JreCompat(); graalAvailable = false; jre9Available = false; } jre11Available = instance.jarFileRuntimeMajorVersion() >= 11; Method m1 = null; Method m2 = null; try { m1 = SSLParameters.class.getMethod("setApplicationProtocols", String[].class); m2 = SSLEngine.class.getMethod("getApplicationProtocol"); } catch (ReflectiveOperationException | IllegalArgumentException e) { // Only the newest Java 8 have the ALPN API, so ignore } setApplicationProtocolsMethod = m1; getApplicationProtocolMethod = m2; } public static JreCompat getInstance() { return instance; } public static boolean isGraalAvailable() { return graalAvailable; } public static boolean isAlpnSupported() { return setApplicationProtocolsMethod != null && getApplicationProtocolMethod != null; } public static boolean isJre9Available() { return jre9Available; } public static boolean isJre11Available() { return jre11Available; } // Java 8 implementation of Java 9 methods
Test if the provided exception is an instance of java.lang.reflect.InaccessibleObjectException.
Params:
  • t – The exception to test
Returns:true if the exception is an instance of InaccessibleObjectException, otherwise false
/** * Test if the provided exception is an instance of * java.lang.reflect.InaccessibleObjectException. * * @param t The exception to test * * @return {@code true} if the exception is an instance of * InaccessibleObjectException, otherwise {@code false} */
public boolean isInstanceOfInaccessibleObjectException(Throwable t) { // Exception does not exist prior to Java 9 return false; }
Set the application protocols the server will accept for ALPN
Params:
  • sslParameters – The SSL parameters for a connection
  • protocols – The application protocols to be allowed for that connection
/** * Set the application protocols the server will accept for ALPN * * @param sslParameters The SSL parameters for a connection * @param protocols The application protocols to be allowed for that * connection */
public void setApplicationProtocols(SSLParameters sslParameters, String[] protocols) { if (setApplicationProtocolsMethod != null) { try { setApplicationProtocolsMethod.invoke(sslParameters, (Object) protocols); } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) { throw new UnsupportedOperationException(e); } } else { throw new UnsupportedOperationException(sm.getString("jreCompat.noApplicationProtocols")); } }
Get the application protocol that has been negotiated for connection associated with the given SSLEngine.
Params:
  • sslEngine – The SSLEngine for which to obtain the negotiated protocol
Returns:The name of the negotiated protocol
/** * Get the application protocol that has been negotiated for connection * associated with the given SSLEngine. * * @param sslEngine The SSLEngine for which to obtain the negotiated * protocol * * @return The name of the negotiated protocol */
public String getApplicationProtocol(SSLEngine sslEngine) { if (getApplicationProtocolMethod != null) { try { return (String) getApplicationProtocolMethod.invoke(sslEngine); } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) { throw new UnsupportedOperationException(e); } } else { throw new UnsupportedOperationException(sm.getString("jreCompat.noApplicationProtocol")); } }
Disables caching for JAR URL connections. For Java 8 and earlier, this also disables caching for ALL URL connections.
Throws:
  • IOException – If a dummy JAR URLConnection can not be created
/** * Disables caching for JAR URL connections. For Java 8 and earlier, this also disables * caching for ALL URL connections. * * @throws IOException If a dummy JAR URLConnection can not be created */
public void disableCachingForJarUrlConnections() throws IOException { // Doesn't matter that this JAR doesn't exist - just as // long as the URL is well-formed URL url = new URL("jar:file://dummy.jar!/"); URLConnection uConn = url.openConnection(); uConn.setDefaultUseCaches(false); }
Obtains the URLs for all the JARs on the module path when the JVM starts and adds them to the provided Deque.
Params:
  • classPathUrlsToProcess – The Deque to which the modules should be added
/** * Obtains the URLs for all the JARs on the module path when the JVM starts * and adds them to the provided Deque. * * @param classPathUrlsToProcess The Deque to which the modules should be * added */
public void addBootModulePath(Deque<URL> classPathUrlsToProcess) { // NO-OP for Java 8. There is no module path. }
Creates a new JarFile instance. When running on Java 9 and later, the JarFile will be multi-release JAR aware. While this isn't strictly required to be in this package, it is provided as a convenience method.
Params:
  • s – The JAR file to open
Throws:
  • IOException – If an I/O error occurs creating the JarFile instance
Returns:A JarFile instance based on the provided path
/** * Creates a new JarFile instance. When running on Java 9 and later, the * JarFile will be multi-release JAR aware. While this isn't strictly * required to be in this package, it is provided as a convenience method. * * @param s The JAR file to open * * @return A JarFile instance based on the provided path * * @throws IOException If an I/O error occurs creating the JarFile instance */
public final JarFile jarFileNewInstance(String s) throws IOException { return jarFileNewInstance(new File(s)); }
Creates a new JarFile instance. When running on Java 9 and later, the JarFile will be multi-release JAR aware.
Params:
  • f – The JAR file to open
Throws:
  • IOException – If an I/O error occurs creating the JarFile instance
Returns:A JarFile instance based on the provided file
/** * Creates a new JarFile instance. When running on Java 9 and later, the * JarFile will be multi-release JAR aware. * * @param f The JAR file to open * * @return A JarFile instance based on the provided file * * @throws IOException If an I/O error occurs creating the JarFile instance */
public JarFile jarFileNewInstance(File f) throws IOException { return new JarFile(f); }
Is this JarFile a multi-release JAR file.
Params:
  • jarFile – The JarFile to test
Returns:true If it is a multi-release JAR file and is configured to behave as such.
/** * Is this JarFile a multi-release JAR file. * * @param jarFile The JarFile to test * * @return {@code true} If it is a multi-release JAR file and is configured * to behave as such. */
public boolean jarFileIsMultiRelease(JarFile jarFile) { // Java 8 doesn't support multi-release so default to false return false; } public int jarFileRuntimeMajorVersion() { return RUNTIME_MAJOR_VERSION; }
Is the accessibleObject accessible (as a result of appropriate module exports) on the provided instance?
Params:
  • base – The specific instance to be tested.
  • accessibleObject – The method/field/constructor to be tested.
Returns:{code true} if the AccessibleObject can be accessed otherwise {code false}
/** * Is the accessibleObject accessible (as a result of appropriate module * exports) on the provided instance? * * @param base The specific instance to be tested. * @param accessibleObject The method/field/constructor to be tested. * * @return {code true} if the AccessibleObject can be accessed otherwise * {code false} */
public boolean canAccess(Object base, AccessibleObject accessibleObject) { // Java 8 doesn't support modules so default to true return true; }
Is the given class in an exported package?
Params:
  • type – The class to test
Returns:Always true for Java 8. true if the enclosing package is exported for Java 9+
/** * Is the given class in an exported package? * * @param type The class to test * * @return Always {@code true} for Java 8. {@code true} if the enclosing * package is exported for Java 9+ */
public boolean isExported(Class<?> type) { return true; }
What is the module of the given class?
Params:
  • type – The class to test
Returns:Always true for Java 8. true if the enclosing package is exported for Java 9+
/** * What is the module of the given class? * * @param type The class to test * * @return Always {@code true} for Java 8. {@code true} if the enclosing * package is exported for Java 9+ */
public String getModuleName(Class<?> type) { return "NO_MODULE_JAVA_8"; } }