001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel;
019
020/**
021 * Exception constants.
022 * @since 6.0 (intended to replace the InstructionConstant interface)
023 */
024public final class ExceptionConst {
025
026    /** The mother of all exceptions
027     */
028    public static final Class<Throwable> THROWABLE = Throwable.class;
029    /** Super class of any run-time exception
030     */
031    public static final Class<RuntimeException> RUNTIME_EXCEPTION = RuntimeException.class;
032    /** Super class of any linking exception (aka Linkage Error)
033     */
034    public static final Class<LinkageError> LINKING_EXCEPTION = LinkageError.class;
035    /** Linking Exceptions
036     */
037    public static final Class<ClassCircularityError> CLASS_CIRCULARITY_ERROR = ClassCircularityError.class;
038    public static final Class<ClassFormatError> CLASS_FORMAT_ERROR = ClassFormatError.class;
039    public static final Class<ExceptionInInitializerError> EXCEPTION_IN_INITIALIZER_ERROR = ExceptionInInitializerError.class;
040    public static final Class<IncompatibleClassChangeError> INCOMPATIBLE_CLASS_CHANGE_ERROR = IncompatibleClassChangeError.class;
041    public static final Class<AbstractMethodError> ABSTRACT_METHOD_ERROR = AbstractMethodError.class;
042    public static final Class<IllegalAccessError> ILLEGAL_ACCESS_ERROR = IllegalAccessError.class;
043    public static final Class<InstantiationError> INSTANTIATION_ERROR = InstantiationError.class;
044    public static final Class<NoSuchFieldError> NO_SUCH_FIELD_ERROR = NoSuchFieldError.class;
045    public static final Class<NoSuchMethodError> NO_SUCH_METHOD_ERROR = NoSuchMethodError.class;
046    public static final Class<NoClassDefFoundError> NO_CLASS_DEF_FOUND_ERROR = NoClassDefFoundError.class;
047    public static final Class<UnsatisfiedLinkError> UNSATISFIED_LINK_ERROR = UnsatisfiedLinkError.class;
048    public static final Class<VerifyError> VERIFY_ERROR = VerifyError.class;
049    /* UnsupportedClassVersionError is new in JDK 1.2 */
050//    public static final Class UnsupportedClassVersionError = UnsupportedClassVersionError.class;
051    /** Run-Time Exceptions
052     */
053    public static final Class<NullPointerException> NULL_POINTER_EXCEPTION = NullPointerException.class;
054    public static final Class<ArrayIndexOutOfBoundsException> ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION
055                                                            = ArrayIndexOutOfBoundsException.class;
056    public static final Class<ArithmeticException> ARITHMETIC_EXCEPTION = ArithmeticException.class;
057    public static final Class<NegativeArraySizeException> NEGATIVE_ARRAY_SIZE_EXCEPTION = NegativeArraySizeException.class;
058    public static final Class<ClassCastException> CLASS_CAST_EXCEPTION = ClassCastException.class;
059    public static final Class<IllegalMonitorStateException> ILLEGAL_MONITOR_STATE = IllegalMonitorStateException.class;
060
061    /**
062     * Pre-defined exception arrays according to chapters 5.1-5.4 of the Java Virtual
063     * Machine Specification
064     */
065    private static final Class<?>[] EXCS_CLASS_AND_INTERFACE_RESOLUTION = {
066            NO_CLASS_DEF_FOUND_ERROR, CLASS_FORMAT_ERROR, VERIFY_ERROR, ABSTRACT_METHOD_ERROR,
067            EXCEPTION_IN_INITIALIZER_ERROR, ILLEGAL_ACCESS_ERROR
068    }; // Chapter 5.1
069    private static final Class<?>[] EXCS_FIELD_AND_METHOD_RESOLUTION = {
070            NO_SUCH_FIELD_ERROR, ILLEGAL_ACCESS_ERROR, NO_SUCH_METHOD_ERROR
071    }; // Chapter 5.2
072    private static final Class<?>[] EXCS_INTERFACE_METHOD_RESOLUTION = new Class[0]; // Chapter 5.3 (as below)
073    private static final Class<?>[] EXCS_STRING_RESOLUTION = new Class[0];
074    // Chapter 5.4 (no errors but the ones that _always_ could happen! How stupid.)
075    private static final Class<?>[] EXCS_ARRAY_EXCEPTION = {
076            NULL_POINTER_EXCEPTION, ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION
077    };
078
079    /**
080     * Enum corresponding to the various Exception Class arrays,
081     * used by {@link ExceptionConst#createExceptions(EXCS, Class...)}
082     */
083    public enum EXCS {
084        EXCS_CLASS_AND_INTERFACE_RESOLUTION,
085        EXCS_FIELD_AND_METHOD_RESOLUTION,
086        EXCS_INTERFACE_METHOD_RESOLUTION,
087        EXCS_STRING_RESOLUTION,
088        EXCS_ARRAY_EXCEPTION,
089    }
090
091    // helper method to merge exception class arrays
092    private static Class<?>[] mergeExceptions(final Class<?>[] input, final Class<?> ... extraClasses) {
093        final int extraLen = extraClasses == null ? 0 : extraClasses.length;
094        final Class<?>[] excs = new Class<?>[input.length + extraLen];
095        System.arraycopy(input, 0, excs, 0, input.length);
096        if (extraLen > 0) {
097            System.arraycopy(extraClasses, 0, excs, input.length, extraLen);
098        }
099        return excs;
100    }
101
102    /**
103     * Creates a copy of the specified Exception Class array combined with any additional Exception classes.
104     * @param type the basic array type
105     * @param extraClasses additional classes, if any
106     * @return the merged array
107     */
108    public static Class<?>[] createExceptions(final EXCS type, final Class<?> ... extraClasses) {
109        switch (type) {
110        case EXCS_CLASS_AND_INTERFACE_RESOLUTION:
111            return mergeExceptions(EXCS_CLASS_AND_INTERFACE_RESOLUTION, extraClasses);
112        case EXCS_ARRAY_EXCEPTION:
113            return mergeExceptions(EXCS_ARRAY_EXCEPTION, extraClasses);
114        case EXCS_FIELD_AND_METHOD_RESOLUTION:
115            return mergeExceptions(EXCS_FIELD_AND_METHOD_RESOLUTION, extraClasses);
116        case EXCS_INTERFACE_METHOD_RESOLUTION:
117            return mergeExceptions(EXCS_INTERFACE_METHOD_RESOLUTION, extraClasses);
118        case EXCS_STRING_RESOLUTION:
119            return mergeExceptions(EXCS_STRING_RESOLUTION, extraClasses);
120        default:
121            throw new AssertionError("Cannot happen; unexpected enum value: " + type);
122        }
123    }
124
125
126}