View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   *
17   */
18  package org.apache.bcel;
19  
20  /**
21   * Exception constants.
22   * @since 6.0 (intended to replace the InstructionConstant interface)
23   */
24  public final class ExceptionConst {
25  
26      /**
27       * The mother of all exceptions
28       */
29      public static final Class<Throwable> THROWABLE = Throwable.class;
30  
31      /**
32       * Super class of any run-time exception
33       */
34      public static final Class<RuntimeException> RUNTIME_EXCEPTION = RuntimeException.class;
35  
36      /**
37       * Super class of any linking exception (aka Linkage Error)
38       */
39      public static final Class<LinkageError> LINKING_EXCEPTION = LinkageError.class;
40  
41      /**
42       * Linking Exceptions
43       */
44      public static final Class<ClassCircularityError> CLASS_CIRCULARITY_ERROR = ClassCircularityError.class;
45      public static final Class<ClassFormatError> CLASS_FORMAT_ERROR = ClassFormatError.class;
46      public static final Class<ExceptionInInitializerError> EXCEPTION_IN_INITIALIZER_ERROR = ExceptionInInitializerError.class;
47      public static final Class<IncompatibleClassChangeError> INCOMPATIBLE_CLASS_CHANGE_ERROR = IncompatibleClassChangeError.class;
48      public static final Class<AbstractMethodError> ABSTRACT_METHOD_ERROR = AbstractMethodError.class;
49      public static final Class<IllegalAccessError> ILLEGAL_ACCESS_ERROR = IllegalAccessError.class;
50      public static final Class<InstantiationError> INSTANTIATION_ERROR = InstantiationError.class;
51      public static final Class<NoSuchFieldError> NO_SUCH_FIELD_ERROR = NoSuchFieldError.class;
52      public static final Class<NoSuchMethodError> NO_SUCH_METHOD_ERROR = NoSuchMethodError.class;
53      public static final Class<NoClassDefFoundError> NO_CLASS_DEF_FOUND_ERROR = NoClassDefFoundError.class;
54      public static final Class<UnsatisfiedLinkError> UNSATISFIED_LINK_ERROR = UnsatisfiedLinkError.class;
55      public static final Class<VerifyError> VERIFY_ERROR = VerifyError.class;
56      /* UnsupportedClassVersionError is new in JDK 1.2 */
57  //    public static final Class UnsupportedClassVersionError = UnsupportedClassVersionError.class;
58  
59      /**
60       * Run-Time Exceptions
61       */
62      public static final Class<NullPointerException> NULL_POINTER_EXCEPTION = NullPointerException.class;
63      public static final Class<ArrayIndexOutOfBoundsException> ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION
64                                                              = ArrayIndexOutOfBoundsException.class;
65      public static final Class<ArithmeticException> ARITHMETIC_EXCEPTION = ArithmeticException.class;
66      public static final Class<NegativeArraySizeException> NEGATIVE_ARRAY_SIZE_EXCEPTION = NegativeArraySizeException.class;
67      public static final Class<ClassCastException> CLASS_CAST_EXCEPTION = ClassCastException.class;
68      public static final Class<IllegalMonitorStateException> ILLEGAL_MONITOR_STATE = IllegalMonitorStateException.class;
69  
70      /**
71       * Pre-defined exception arrays according to chapters 5.1-5.4 of the Java Virtual
72       * Machine Specification
73       */
74      private static final Class<?>[] EXCS_CLASS_AND_INTERFACE_RESOLUTION = {
75              NO_CLASS_DEF_FOUND_ERROR, CLASS_FORMAT_ERROR, VERIFY_ERROR, ABSTRACT_METHOD_ERROR,
76              EXCEPTION_IN_INITIALIZER_ERROR, ILLEGAL_ACCESS_ERROR
77      }; // Chapter 5.1
78      private static final Class<?>[] EXCS_FIELD_AND_METHOD_RESOLUTION = {
79              NO_SUCH_FIELD_ERROR, ILLEGAL_ACCESS_ERROR, NO_SUCH_METHOD_ERROR
80      }; // Chapter 5.2
81      private static final Class<?>[] EXCS_INTERFACE_METHOD_RESOLUTION = new Class[0]; // Chapter 5.3 (as below)
82      private static final Class<?>[] EXCS_STRING_RESOLUTION = new Class[0];
83      // Chapter 5.4 (no errors but the ones that _always_ could happen! How stupid.)
84      private static final Class<?>[] EXCS_ARRAY_EXCEPTION = {
85              NULL_POINTER_EXCEPTION, ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION
86      };
87  
88      /**
89       * Enum corresponding to the various Exception Class arrays,
90       * used by {@link ExceptionConst#createExceptions(EXCS, Class...)}
91       */
92      public enum EXCS {
93          EXCS_CLASS_AND_INTERFACE_RESOLUTION,
94          EXCS_FIELD_AND_METHOD_RESOLUTION,
95          EXCS_INTERFACE_METHOD_RESOLUTION,
96          EXCS_STRING_RESOLUTION,
97          EXCS_ARRAY_EXCEPTION,
98      }
99  
100     // helper method to merge exception class arrays
101     private static Class<?>[] mergeExceptions(final Class<?>[] input, final Class<?> ... extraClasses) {
102         final int extraLen = extraClasses == null ? 0 : extraClasses.length;
103         final Class<?>[] excs = new Class<?>[input.length + extraLen];
104         System.arraycopy(input, 0, excs, 0, input.length);
105         if (extraLen > 0) {
106             System.arraycopy(extraClasses, 0, excs, input.length, extraLen);
107         }
108         return excs;
109     }
110 
111     /**
112      * Creates a copy of the specified Exception Class array combined with any additional Exception classes.
113      * @param type the basic array type
114      * @param extraClasses additional classes, if any
115      * @return the merged array
116      */
117     public static Class<?>[] createExceptions(final EXCS type, final Class<?> ... extraClasses) {
118         switch (type) {
119         case EXCS_CLASS_AND_INTERFACE_RESOLUTION:
120             return mergeExceptions(EXCS_CLASS_AND_INTERFACE_RESOLUTION, extraClasses);
121         case EXCS_ARRAY_EXCEPTION:
122             return mergeExceptions(EXCS_ARRAY_EXCEPTION, extraClasses);
123         case EXCS_FIELD_AND_METHOD_RESOLUTION:
124             return mergeExceptions(EXCS_FIELD_AND_METHOD_RESOLUTION, extraClasses);
125         case EXCS_INTERFACE_METHOD_RESOLUTION:
126             return mergeExceptions(EXCS_INTERFACE_METHOD_RESOLUTION, extraClasses);
127         case EXCS_STRING_RESOLUTION:
128             return mergeExceptions(EXCS_STRING_RESOLUTION, extraClasses);
129         default:
130             throw new AssertionError("Cannot happen; unexpected enum value: " + type);
131         }
132     }
133 
134 
135 }