java/classfile/src/org/netbeans/modules/classfile/Access.java

/*
 * 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.
 */
/*
 * Contributor(s): Thomas Ball
 */

package org.netbeans.modules.classfile;

/**
 * A utility class defining access flags and access utility methods.
 * Access flags are as defined by the Java Virtual Machine Specification
 * Second Edition, tables 4.1, 4.4, 4.5 and 4.7.
 *
 * @author Thomas Ball
 */
public class Access {

    /** Declared public, may be accessed from outside its package. */
    public static final int PUBLIC       = 0x0001;

    /** Declared private, usable only within the defining class. */
    public static final int PRIVATE      = 0x0002;

    /** Declared protected, may be accessed within subclasses. */
    public static final int PROTECTED    = 0x0004;

    /** Declared static. */
    public static final int STATIC       = 0x0008;

    /**
     * Declared final.  For classes this means no subclassing allowed.
     * For fields it means no further assignment allowed after initialization.
     * For methods it means that the method cannot be overridden.
     */
    public static final int FINAL        = 0x0010;

    /** Declared synchronized; invocation is wrapped in a monitor lock. */
    public static final int SYNCHRONIZED = 0x0020;

    /**
     * Treat superclass methods specially when invoked by the
     * <i>invokespecial</i> instruction.  This access only applies to
     * classes, and shares the same value as SYNCHRONIZED.
     */
    public static final int SUPER        = 0x0020;

    /** Open module in the Module attribute.
     * @since 1.52
     */
    public static final int OPEN = 0x0020;

    /** Transitive requires in the Module attribute.
     * @since 1.52
     */
    public static final int TRANSITIVE = 0x0020;


    /** Declared volatile; cannot be cached. */
    public static final int VOLATILE     = 0x0040;

    /** A bridge method, generated by the compiler. */
    public static final int BRIDGE       = 0x0040;

    /** Static requires in the Module attribute.
     * @since 1.52
     */
    public static final int STATIC_PHASE = 0x0040;

    /** 
     * Declared transient; not written or read by a persistent object 
     * manager 
     */
    public static final int TRANSIENT    = 0x0080;

    /** Declared with a variable number of arguments. */
    public static final int VARARGS      = 0x0080;

    /** Declared native; implemented in a language other than Java. */
    public static final int NATIVE       = 0x0100;

    /** Is an interface, not a class. */
    public static final int INTERFACE    = 0x0200;

    /** Declared abstract; must not be instantiated. */
    public static final int ABSTRACT     = 0x0400;

    /** Declared strictfp; floating point mode is FP-strict. */
    public static final int STRICT       = 0x0800;

    /** Declared synthetic, not present in the source file. */
    public static final int SYNTHETIC    = 0x1000;

    /** Declared as an annotation type. */
    public static final int ANNOTATION   = 0x2000;

    /** 
     * For classes, declared as an enum type.  For fields, declared as
     * an element of an enum.
     */
    public static final int ENUM         = 0x4000;
    
    /**
     * Mandated method parameter.
     * @since 1.51
     */
    public static final int MANDATED      = 0x8000; // method parameter

    /**
     * For classes, declared as an module.
     * @since 1.51
     */
    public static final int MODULE        = 0x8000; // class

    /**
     * Return a text representation for a given set of access flags.  
     * Here are some examples:
     * <DL>
     *  <DD><CODE>"public static final"</CODE>,</DD>
     *  <DD><CODE>"package private"</CODE>, or</DD>
     *  <DD><CODE>"protected transient"</CODE>.</DD>
     * </DL>
     * Note: only access flags that map to Java modifier keywords are returned.
     * @param access the mask of flags denoting access permission.
     * @return a text representation of the access flags.
     */
    public static String toString(int access) {
        StringBuffer sb = new StringBuffer();
        if ((access & PUBLIC) == PUBLIC)
            sb.append("public "); //NOI18N
        if ((access & PRIVATE) == PRIVATE)
            sb.append("private "); //NOI18N
        if ((access & PROTECTED) == PROTECTED)
            sb.append("protected "); //NOI18N
        if ((access & (PUBLIC | PRIVATE | PROTECTED)) == 0)
            sb.append("package private "); //NOI18N
        if ((access & STATIC) == STATIC)
            sb.append("static "); //NOI18N
        if ((access & FINAL) == FINAL)
            sb.append("final "); //NOI18N
        if ((access & SYNCHRONIZED) == SYNCHRONIZED)
            sb.append("synchronized "); //NOI18N
        if ((access & VOLATILE) == VOLATILE)
            sb.append("volatile "); //NOI18N
        if ((access & TRANSIENT) == TRANSIENT)
            sb.append("transient "); //NOI18N
        if ((access & NATIVE) == NATIVE)
            sb.append("native "); //NOI18N
        if ((access & ABSTRACT) == ABSTRACT)
            sb.append("abstract "); //NOI18N
        if ((access & STRICT) == STRICT)
            sb.append("strict "); //NOI18N

        // trim trailing space
        return sb.substring(0, sb.length()-1);
    }

    public static boolean isStatic(int access) {
        return ((access & STATIC) == STATIC);
    }

    public static final boolean isPublic(int access) {
        return ((access & PUBLIC) == PUBLIC);
    }

    public static final boolean isProtected(int access) {
        return ((access & PROTECTED) == PROTECTED);
    }

    public static final boolean isPackagePrivate(int access) {
        return ((access & (PUBLIC | PRIVATE | PROTECTED)) == 0);
    }

    public static final boolean isPrivate(int access) {
        return ((access & PRIVATE) == PRIVATE);
    }

    private Access() {
        // don't allow instantiation
    }
}