jdk/src/share/classes/java/lang/reflect/Modifier.java
changeset 2 90ce3da70b43
child 51 6fe31bc95bbc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/lang/reflect/Modifier.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,357 @@
+/*
+ * Copyright 1996-2004 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.lang.reflect;
+
+import java.security.AccessController;
+import sun.reflect.LangReflectAccess;
+import sun.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 <a
+ * href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/VMSpecTOC.doc.html"><i>The
+ * Java</i><sup><small>TM</small></sup> <i>Virtual Machine Specification, Second
+ * edition</i></a> tables
+ * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#75734">4.1</a>,
+ * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#88358">4.4</a>,
+ * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#75568">4.5</a>, and
+ * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#88478">4.7</a>.
+ *
+ * @see Class#getModifiers()
+ * @see Member#getModifiers()
+ *
+ * @author Nakul Saraiya
+ * @author Kenneth Russell
+ */
+public
+class Modifier {
+
+    /*
+     * Bootstrapping protocol between java.lang and java.lang.reflect
+     *  packages
+     */
+    static {
+        sun.reflect.ReflectionFactory factory =
+            (sun.reflect.ReflectionFactory) 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 <a
+     * href="http://java.sun.com/docs/books/jls/second_edition/html/j.title.doc.html"><em>The
+     * Java Language Specification, Second Edition</em></a> sections
+     * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#21613">&sect;8.1.1</a>,
+     * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#78091">&sect;8.3.1</a>,
+     * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#78188">&sect;8.4.3</a>,
+     * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#42018">&sect;8.8.3</a>, and
+     * <a href="http://java.sun.com/docs/books/jls/second_edition/html/interfaces.doc.html#235947">&sect;9.1.1</a>.
+     * 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.
+     *
+     * @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) {
+        StringBuffer sb = new StringBuffer();
+        int len;
+
+        if ((mod & PUBLIC) != 0)        sb.append("public ");
+        if ((mod & PROTECTED) != 0)     sb.append("protected ");
+        if ((mod & PRIVATE) != 0)       sb.append("private ");
+
+        /* Canonical order */
+        if ((mod & ABSTRACT) != 0)      sb.append("abstract ");
+        if ((mod & STATIC) != 0)        sb.append("static ");
+        if ((mod & FINAL) != 0)         sb.append("final ");
+        if ((mod & TRANSIENT) != 0)     sb.append("transient ");
+        if ((mod & VOLATILE) != 0)      sb.append("volatile ");
+        if ((mod & SYNCHRONIZED) != 0)  sb.append("synchronized ");
+        if ((mod & NATIVE) != 0)        sb.append("native ");
+        if ((mod & STRICT) != 0)        sb.append("strictfp ");
+        if ((mod & INTERFACE) != 0)     sb.append("interface ");
+
+        if ((len = sb.length()) > 0)    /* trim trailing space */
+            return sb.toString().substring(0, len-1);
+        return "";
+    }
+
+    /*
+     * Access modifier flag constants from <em>The Java Virtual
+     * Machine Specification, Second Edition</em>, tables 4.1, 4.4,
+     * 4.5, and 4.7.
+     */
+
+    /**
+     * 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 boolean isSynthetic(int mod) {
+      return (mod & SYNTHETIC) != 0;
+    }
+}