# HG changeset patch # User bchristi # Date 1574186566 28800 # Node ID faac483dfb308788f37b7a3864ee9627f082a59f # Parent fc998c509521f1e4dd4e7e2246d41a8ddd7af9f1 8233272: The Class.forName specification should be updated to match the long-standing implementation with respect to class linking Reviewed-by: dholmes, mchung diff -r fc998c509521 -r faac483dfb30 src/java.base/share/classes/java/lang/Class.java --- a/src/java.base/share/classes/java/lang/Class.java Fri Nov 15 11:05:03 2019 +0100 +++ b/src/java.base/share/classes/java/lang/Class.java Tue Nov 19 10:02:46 2019 -0800 @@ -325,6 +325,10 @@ * @throws ExceptionInInitializerError if the initialization provoked * by this method fails * @throws ClassNotFoundException if the class cannot be located + * + * @jls 12.2 Loading of Classes and Interfaces + * @jls 12.3 Linking of Classes and Interfaces + * @jls 12.4 Initialization of Classes and Interfaces */ @CallerSensitive public static Class forName(String className) @@ -339,7 +343,7 @@ * interface with the given string name, using the given class loader. * Given the fully qualified name for a class or interface (in the same * format returned by {@code getName}) this method attempts to - * locate, load, and link the class or interface. The specified class + * locate and load the class or interface. The specified class * loader is used to load the class or interface. If the parameter * {@code loader} is null, the class is loaded through the bootstrap * class loader. The class is initialized only if the @@ -374,7 +378,7 @@ * is accessible to its caller. * * @param name fully qualified name of the desired class - * @param initialize if {@code true} the class will be initialized. + * @param initialize if {@code true} the class will be initialized (which implies linking). * See Section 12.4 of The Java Language Specification. * @param loader class loader from which the class must be loaded * @return class object representing the desired class @@ -392,6 +396,10 @@ * * @see java.lang.Class#forName(String) * @see java.lang.ClassLoader + * + * @jls 12.2 Loading of Classes and Interfaces + * @jls 12.3 Linking of Classes and Interfaces + * @jls 12.4 Initialization of Classes and Interfaces * @since 1.2 */ @CallerSensitive @@ -427,9 +435,9 @@ * Returns the {@code Class} with the given * binary name in the given module. * - *

This method attempts to locate, load, and link the class or interface. - * It does not run the class initializer. If the class is not found, this - * method returns {@code null}.

+ *

This method attempts to locate and load the class or interface. + * It does not link the class, and does not run the class initializer. + * If the class is not found, this method returns {@code null}.

* *

If the class loader of the given module defines other modules and * the given name is a class defined in a different module, this method @@ -465,6 +473,8 @@ * in a module. * * + * @jls 12.2 Loading of Classes and Interfaces + * @jls 12.3 Linking of Classes and Interfaces * @since 9 * @spec JPMS */ diff -r fc998c509521 -r faac483dfb30 test/jdk/java/lang/Class/forName/NonLinking/Container.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/jdk/java/lang/Class/forName/NonLinking/Container.java Tue Nov 19 10:02:46 2019 -0800 @@ -0,0 +1,31 @@ +/* + * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +public class Container { + + public Container(MissingClass m) {} + + public Container() { + this(new MissingClass() {}); + } +} diff -r fc998c509521 -r faac483dfb30 test/jdk/java/lang/Class/forName/NonLinking/MissingClass.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/jdk/java/lang/Class/forName/NonLinking/MissingClass.java Tue Nov 19 10:02:46 2019 -0800 @@ -0,0 +1,24 @@ +/* + * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +public class MissingClass {} diff -r fc998c509521 -r faac483dfb30 test/jdk/java/lang/Class/forName/NonLinking/NonLinking.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/jdk/java/lang/Class/forName/NonLinking/NonLinking.java Tue Nov 19 10:02:46 2019 -0800 @@ -0,0 +1,77 @@ +/* + * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +import java.net.URL; +import java.net.URLClassLoader; +import java.nio.file.Path; +import java.nio.file.Paths; + +/* + * @test + * @bug 8231924 8233091 8233272 + * @summary Confirm load (but not link) behavior of Class.forName() + * @library /test/lib + * + * @compile MissingClass.java Container.java + * + * @run driver ClassFileInstaller -jar classes.jar Container Container$1 + * + * @run main/othervm NonLinking init + * @run main/othervm NonLinking load + */ +/* + * The @compile and '@main ClassFileInstaller' tasks above create a classes.jar + * file containing the .class file for Container, but not MissingClass. + */ + +public class NonLinking { + public static void main(String[] args) throws Throwable { + Path jarPath = Paths.get("classes.jar"); + URL url = jarPath.toUri().toURL(); + URLClassLoader ucl1 = new URLClassLoader("UCL1", + new URL[] { url }, + null); // Don't delegate + switch(args[0]) { + case "init": + try { + // Trying to initialize Container without MissingClass -> NCDFE + Class.forName("Container", true, ucl1); + throw new RuntimeException("Missed expected NoClassDefFoundError"); + } catch (NoClassDefFoundError expected) { + final String CLASSNAME = "MissingClass"; + Throwable cause = expected.getCause(); + if (!cause.getMessage().contains(CLASSNAME)) { + throw new RuntimeException("Cause of NoClassDefFoundError does not contain \"" + CLASSNAME + "\"", cause); + } + } + break; + case "load": + // Loading (but not linking) Container will succeed. + // Before 8233091, this fails with NCDFE due to linking. + Class.forName("Container", false, ucl1); + break; + default: + throw new RuntimeException("Unknown command: " + args[0]); + } + } +}