src/java.base/share/classes/java/lang/reflect/Modifier.java
changeset 47216 71c04702a3d5
parent 45434 4582657c7260
child 54952 a978d86ac389
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/reflect/Modifier.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,494 @@
+/*
+ * Copyright (c) 1996, 2013, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package java.lang.reflect;
+
+import java.security.AccessController;
+import java.util.StringJoiner;
+import jdk.internal.reflect.LangReflectAccess;
+import jdk.internal.reflect.ReflectionFactory;
+
+/**
+ * The Modifier class provides {@code static} methods and
+ * constants to decode class and member access modifiers.  The sets of
+ * modifiers are represented as integers with distinct bit positions
+ * representing different modifiers.  The values for the constants
+ * representing the modifiers are taken from the tables in sections 4.1, 4.4, 4.5, and 4.7 of
+ * <cite>The Java&trade; Virtual Machine Specification</cite>.
+ *
+ * @see Class#getModifiers()
+ * @see Member#getModifiers()
+ *
+ * @author Nakul Saraiya
+ * @author Kenneth Russell
+ * @since 1.1
+ */
+public class Modifier {
+
+    /*
+     * Bootstrapping protocol between java.lang and java.lang.reflect
+     *  packages
+     */
+    static {
+        ReflectionFactory factory = AccessController.doPrivileged(
+                new ReflectionFactory.GetReflectionFactoryAction());
+        factory.setLangReflectAccess(new java.lang.reflect.ReflectAccess());
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code public} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code public} modifier; {@code false} otherwise.
+     */
+    public static boolean isPublic(int mod) {
+        return (mod & PUBLIC) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code private} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code private} modifier; {@code false} otherwise.
+     */
+    public static boolean isPrivate(int mod) {
+        return (mod & PRIVATE) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code protected} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code protected} modifier; {@code false} otherwise.
+     */
+    public static boolean isProtected(int mod) {
+        return (mod & PROTECTED) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code static} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code static} modifier; {@code false} otherwise.
+     */
+    public static boolean isStatic(int mod) {
+        return (mod & STATIC) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code final} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code final} modifier; {@code false} otherwise.
+     */
+    public static boolean isFinal(int mod) {
+        return (mod & FINAL) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code synchronized} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code synchronized} modifier; {@code false} otherwise.
+     */
+    public static boolean isSynchronized(int mod) {
+        return (mod & SYNCHRONIZED) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code volatile} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code volatile} modifier; {@code false} otherwise.
+     */
+    public static boolean isVolatile(int mod) {
+        return (mod & VOLATILE) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code transient} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code transient} modifier; {@code false} otherwise.
+     */
+    public static boolean isTransient(int mod) {
+        return (mod & TRANSIENT) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code native} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code native} modifier; {@code false} otherwise.
+     */
+    public static boolean isNative(int mod) {
+        return (mod & NATIVE) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code interface} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code interface} modifier; {@code false} otherwise.
+     */
+    public static boolean isInterface(int mod) {
+        return (mod & INTERFACE) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code abstract} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code abstract} modifier; {@code false} otherwise.
+     */
+    public static boolean isAbstract(int mod) {
+        return (mod & ABSTRACT) != 0;
+    }
+
+    /**
+     * Return {@code true} if the integer argument includes the
+     * {@code strictfp} modifier, {@code false} otherwise.
+     *
+     * @param   mod a set of modifiers
+     * @return {@code true} if {@code mod} includes the
+     * {@code strictfp} modifier; {@code false} otherwise.
+     */
+    public static boolean isStrict(int mod) {
+        return (mod & STRICT) != 0;
+    }
+
+    /**
+     * Return a string describing the access modifier flags in
+     * the specified modifier. For example:
+     * <blockquote><pre>
+     *    public final synchronized strictfp
+     * </pre></blockquote>
+     * The modifier names are returned in an order consistent with the
+     * suggested modifier orderings given in sections 8.1.1, 8.3.1, 8.4.3, 8.8.3, and 9.1.1 of
+     * <cite>The Java&trade; Language Specification</cite>.
+     * The full modifier ordering used by this method is:
+     * <blockquote> {@code
+     * public protected private abstract static final transient
+     * volatile synchronized native strictfp
+     * interface } </blockquote>
+     * The {@code interface} modifier discussed in this class is
+     * not a true modifier in the Java language and it appears after
+     * all other modifiers listed by this method.  This method may
+     * return a string of modifiers that are not valid modifiers of a
+     * Java entity; in other words, no checking is done on the
+     * possible validity of the combination of modifiers represented
+     * by the input.
+     *
+     * Note that to perform such checking for a known kind of entity,
+     * such as a constructor or method, first AND the argument of
+     * {@code toString} with the appropriate mask from a method like
+     * {@link #constructorModifiers} or {@link #methodModifiers}.
+     *
+     * @param   mod a set of modifiers
+     * @return  a string representation of the set of modifiers
+     * represented by {@code mod}
+     */
+    public static String toString(int mod) {
+        StringJoiner sj = new StringJoiner(" ");
+
+        if ((mod & PUBLIC) != 0)        sj.add("public");
+        if ((mod & PROTECTED) != 0)     sj.add("protected");
+        if ((mod & PRIVATE) != 0)       sj.add("private");
+
+        /* Canonical order */
+        if ((mod & ABSTRACT) != 0)      sj.add("abstract");
+        if ((mod & STATIC) != 0)        sj.add("static");
+        if ((mod & FINAL) != 0)         sj.add("final");
+        if ((mod & TRANSIENT) != 0)     sj.add("transient");
+        if ((mod & VOLATILE) != 0)      sj.add("volatile");
+        if ((mod & SYNCHRONIZED) != 0)  sj.add("synchronized");
+        if ((mod & NATIVE) != 0)        sj.add("native");
+        if ((mod & STRICT) != 0)        sj.add("strictfp");
+        if ((mod & INTERFACE) != 0)     sj.add("interface");
+
+        return sj.toString();
+    }
+
+    /*
+     * Access modifier flag constants from tables 4.1, 4.4, 4.5, and 4.7 of
+     * <cite>The Java&trade; Virtual Machine Specification</cite>
+     */
+
+    /**
+     * The {@code int} value representing the {@code public}
+     * modifier.
+     */
+    public static final int PUBLIC           = 0x00000001;
+
+    /**
+     * The {@code int} value representing the {@code private}
+     * modifier.
+     */
+    public static final int PRIVATE          = 0x00000002;
+
+    /**
+     * The {@code int} value representing the {@code protected}
+     * modifier.
+     */
+    public static final int PROTECTED        = 0x00000004;
+
+    /**
+     * The {@code int} value representing the {@code static}
+     * modifier.
+     */
+    public static final int STATIC           = 0x00000008;
+
+    /**
+     * The {@code int} value representing the {@code final}
+     * modifier.
+     */
+    public static final int FINAL            = 0x00000010;
+
+    /**
+     * The {@code int} value representing the {@code synchronized}
+     * modifier.
+     */
+    public static final int SYNCHRONIZED     = 0x00000020;
+
+    /**
+     * The {@code int} value representing the {@code volatile}
+     * modifier.
+     */
+    public static final int VOLATILE         = 0x00000040;
+
+    /**
+     * The {@code int} value representing the {@code transient}
+     * modifier.
+     */
+    public static final int TRANSIENT        = 0x00000080;
+
+    /**
+     * The {@code int} value representing the {@code native}
+     * modifier.
+     */
+    public static final int NATIVE           = 0x00000100;
+
+    /**
+     * The {@code int} value representing the {@code interface}
+     * modifier.
+     */
+    public static final int INTERFACE        = 0x00000200;
+
+    /**
+     * The {@code int} value representing the {@code abstract}
+     * modifier.
+     */
+    public static final int ABSTRACT         = 0x00000400;
+
+    /**
+     * The {@code int} value representing the {@code strictfp}
+     * modifier.
+     */
+    public static final int STRICT           = 0x00000800;
+
+    // Bits not (yet) exposed in the public API either because they
+    // have different meanings for fields and methods and there is no
+    // way to distinguish between the two in this class, or because
+    // they are not Java programming language keywords
+    static final int BRIDGE    = 0x00000040;
+    static final int VARARGS   = 0x00000080;
+    static final int SYNTHETIC = 0x00001000;
+    static final int ANNOTATION  = 0x00002000;
+    static final int ENUM      = 0x00004000;
+    static final int MANDATED  = 0x00008000;
+    static boolean isSynthetic(int mod) {
+      return (mod & SYNTHETIC) != 0;
+    }
+
+    static boolean isMandated(int mod) {
+      return (mod & MANDATED) != 0;
+    }
+
+    // Note on the FOO_MODIFIERS fields and fooModifiers() methods:
+    // the sets of modifiers are not guaranteed to be constants
+    // across time and Java SE releases. Therefore, it would not be
+    // appropriate to expose an external interface to this information
+    // that would allow the values to be treated as Java-level
+    // constants since the values could be constant folded and updates
+    // to the sets of modifiers missed. Thus, the fooModifiers()
+    // methods return an unchanging values for a given release, but a
+    // value that can potentially change over time.
+
+    /**
+     * The Java source modifiers that can be applied to a class.
+     * @jls 8.1.1 Class Modifiers
+     */
+    private static final int CLASS_MODIFIERS =
+        Modifier.PUBLIC         | Modifier.PROTECTED    | Modifier.PRIVATE |
+        Modifier.ABSTRACT       | Modifier.STATIC       | Modifier.FINAL   |
+        Modifier.STRICT;
+
+    /**
+     * The Java source modifiers that can be applied to an interface.
+     * @jls 9.1.1 Interface Modifiers
+     */
+    private static final int INTERFACE_MODIFIERS =
+        Modifier.PUBLIC         | Modifier.PROTECTED    | Modifier.PRIVATE |
+        Modifier.ABSTRACT       | Modifier.STATIC       | Modifier.STRICT;
+
+
+    /**
+     * The Java source modifiers that can be applied to a constructor.
+     * @jls 8.8.3 Constructor Modifiers
+     */
+    private static final int CONSTRUCTOR_MODIFIERS =
+        Modifier.PUBLIC         | Modifier.PROTECTED    | Modifier.PRIVATE;
+
+    /**
+     * The Java source modifiers that can be applied to a method.
+     * @jls8.4.3  Method Modifiers
+     */
+    private static final int METHOD_MODIFIERS =
+        Modifier.PUBLIC         | Modifier.PROTECTED    | Modifier.PRIVATE |
+        Modifier.ABSTRACT       | Modifier.STATIC       | Modifier.FINAL   |
+        Modifier.SYNCHRONIZED   | Modifier.NATIVE       | Modifier.STRICT;
+
+    /**
+     * The Java source modifiers that can be applied to a field.
+     * @jls 8.3.1  Field Modifiers
+     */
+    private static final int FIELD_MODIFIERS =
+        Modifier.PUBLIC         | Modifier.PROTECTED    | Modifier.PRIVATE |
+        Modifier.STATIC         | Modifier.FINAL        | Modifier.TRANSIENT |
+        Modifier.VOLATILE;
+
+    /**
+     * The Java source modifiers that can be applied to a method or constructor parameter.
+     * @jls 8.4.1 Formal Parameters
+     */
+    private static final int PARAMETER_MODIFIERS =
+        Modifier.FINAL;
+
+    /**
+     *
+     */
+    static final int ACCESS_MODIFIERS =
+        Modifier.PUBLIC | Modifier.PROTECTED | Modifier.PRIVATE;
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a class.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a class.
+     *
+     * @jls 8.1.1 Class Modifiers
+     * @since 1.7
+     */
+    public static int classModifiers() {
+        return CLASS_MODIFIERS;
+    }
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to an interface.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to an interface.
+     *
+     * @jls 9.1.1 Interface Modifiers
+     * @since 1.7
+     */
+    public static int interfaceModifiers() {
+        return INTERFACE_MODIFIERS;
+    }
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a constructor.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a constructor.
+     *
+     * @jls 8.8.3 Constructor Modifiers
+     * @since 1.7
+     */
+    public static int constructorModifiers() {
+        return CONSTRUCTOR_MODIFIERS;
+    }
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a method.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a method.
+     *
+     * @jls 8.4.3 Method Modifiers
+     * @since 1.7
+     */
+    public static int methodModifiers() {
+        return METHOD_MODIFIERS;
+    }
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a field.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a field.
+     *
+     * @jls 8.3.1 Field Modifiers
+     * @since 1.7
+     */
+    public static int fieldModifiers() {
+        return FIELD_MODIFIERS;
+    }
+
+    /**
+     * Return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a parameter.
+     * @return an {@code int} value OR-ing together the source language
+     * modifiers that can be applied to a parameter.
+     *
+     * @jls 8.4.1 Formal Parameters
+     * @since 1.8
+     */
+    public static int parameterModifiers() {
+        return PARAMETER_MODIFIERS;
+    }
+}