1 /*
   2  * Copyright 2004 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 5009601 5010455 5005748
  27  * @summary enum constructors can be declared private
  28  * @author Joseph D. Darcy
  29  *
  30  * @compile -source 1.5 EnumImplicitPrivateConstructor.java
  31  * @run main EnumImplicitPrivateConstructor
  32  */
  33 
  34 import java.util.*;
  35 import java.lang.reflect.*;
  36 import java.lang.annotation.*;
  37 
  38 /*
  39  * Arguably, only the final and abstract should be held in
  40  * ExpectedModifiers; whether or not an enum should be static could be
  41  * inferred from getDeclaringClass and working versions of
  42  * getEnclosingMethod and getEnclosingConstructor.  I.e. if
  43  * getDeclaringClass, getEnclosingMethod, and getEnclosingConstructor
  44  * were all null, the enum is a top-level class and should not be
  45  * static; otherwise, it should be static.
  46  */
  47 
  48 @ExpectedModifiers(Modifier.FINAL)
  49 public enum EnumImplicitPrivateConstructor {
  50     RED(255, 0, 0),
  51     GREEN(0, 255, 0),
  52     BLUE(0, 0, 255);
  53 
  54     private int r, g, b;
  55     EnumImplicitPrivateConstructor(int r, int g, int b) {
  56         this.r = r;
  57         this.g = g;
  58         this.b = b;
  59     }
  60 
  61     /*
  62      * Using reflection, Verify that
  63      * 1. all non-synthetic constructors of enum classes are marked as private.
  64      * 2. top-level enum classes are marked as static
  65      * 3. enum's are marked final and abstract as appropriate
  66      * 4. enum constructors *cannot* be invoked reflectively
  67      */
  68     public static void main(String argv[]) throws Exception {
  69         boolean passed = true;
  70 
  71         Collection<Class> classes = new LinkedHashSet<Class>();
  72 
  73         classes.add(Class.forName("EnumImplicitPrivateConstructor"));
  74         classes.add(Class.forName("EnumImplicitPrivateConstructor$AnotherEnum"));
  75         classes.add(Class.forName("EnumImplicitPrivateConstructor$YetAnotherEnum"));
  76         classes.add(Class.forName("EnumImplicitPrivateConstructor$OneMoreEnum"));
  77 
  78         // Add classes of specialized enum constants
  79         for(Enum e: YetAnotherEnum.values())
  80             classes.add(e.getClass());
  81 
  82         for(Class clazz: classes) {
  83             System.out.println("Testing class " + clazz);
  84 
  85             int classModifiers = clazz.getModifiers();
  86 
  87             // Why is this cast needed?
  88             ExpectedModifiers em = (ExpectedModifiers)clazz.getAnnotation(ExpectedModifiers.class);
  89             if (em != null) {
  90                 System.out.println("\tTesting expected modifiers");
  91                 int expected = em.value();
  92 
  93                 if (expected != (classModifiers & (Modifier.ABSTRACT|Modifier.FINAL|Modifier.STATIC))) {
  94                     passed = false;
  95                     System.out.println("\tFAILED: Expected 0x" + Integer.toHexString(expected) +
  96                                        " got 0x" +Integer.toHexString(classModifiers));
  97                 }
  98             }
  99 
 100             for(Constructor ctor: clazz.getDeclaredConstructors() ) {
 101                 System.out.println("\tTesting constructor " + ctor);
 102 
 103                 // We don't need no stinkin' access rules
 104                 try {
 105                     ctor.setAccessible(true);
 106                 } catch (java.security.AccessControlException ex) {
 107                 }
 108 
 109                 int modifiers = ctor.getModifiers();
 110 
 111                 /*
 112                  * If clazz is for a specialized enum constant, the
 113                  * class will have the ENUM bit set but clazz.isEnum()
 114                  * will be false.  A constructor in such a class must
 115                  * be non-private to allow the parent class to call
 116                  * the constructor.  Therefore, only impose the
 117                  * private constructor check for genuine isEnum
 118                  * classes.
 119                  */
 120                 if (clazz.isEnum()) {
 121                     if ((modifiers & Modifier.PRIVATE) == 0 &&
 122                         ! ctor.isSynthetic() ) {
 123                         passed = false;
 124                         System.out.println("\tFAILED: Constructor not marked private: modifiers 0x" +
 125                                            Integer.toHexString(modifiers));
 126                     }
 127                 }
 128 
 129                 try {
 130                     // Should get exception trying to invoke
 131                     Object o = null;
 132                     try {
 133                         o = ctor.newInstance("abc", 123);
 134                     } catch (IllegalAccessException ex) {
 135                     }
 136 
 137                     /*
 138                      * A better test would query the number (and type)
 139                      * of parameters and create an appropriate
 140                      * argument list since IllegalArgumentException can be
 141                      * thrown for just using the wrong number of arguments.
 142                      */
 143 
 144                     if (o != null) {
 145                         passed = false;
 146                         System.err.println("Error: Created new enum object!");
 147                         System.err.println(o.getClass());
 148                         System.err.println(o.toString());
 149                     }
 150                 } catch (IllegalArgumentException iae) {}
 151 
 152             }
 153         }
 154 
 155         if (!passed)
 156             throw new RuntimeException("Error during testing.");
 157     }
 158 
 159 
 160     /*
 161      * Should be final and not abstract.
 162      */
 163     @ExpectedModifiers(Modifier.FINAL|Modifier.STATIC)
 164     enum AnotherEnum {
 165         YELLOW,
 166         CYAN,
 167         MAGENTA;
 168     }
 169 
 170     /*
 171      * Should be neither final nor abstract.
 172      */
 173     @ExpectedModifiers(Modifier.STATIC)
 174     enum YetAnotherEnum {
 175         GREEN {
 176             int value(){ return 1;}
 177         },
 178 
 179         ORANGE {
 180             int value(){ return 2;}
 181         },
 182 
 183         VIOLET {
 184             int value(){ return 3;}
 185         };
 186 
 187         int value(){ return 0;}
 188     }
 189 
 190     /*
 191      * Should be abstract and not final.
 192      */
 193     @ExpectedModifiers(Modifier.ABSTRACT|Modifier.STATIC)
 194     enum OneMoreEnum {
 195         SANGUINE {
 196             int value(){ return 1;}
 197         },
 198 
 199         VERDANT {
 200             int value(){ return 2;}
 201         },
 202 
 203         CERULEAN {
 204             int value(){ return 3;}
 205         };
 206 
 207         abstract int value();
 208     }
 209 }
 210 
 211 @Retention(RetentionPolicy.RUNTIME)
 212 @interface ExpectedModifiers {
 213     int value();
 214 }