    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 *
    023 * @since 6.0 (intended to replace the InstructionConstant interface)
    024 */
    025public final class ExceptionConst {
    026
    027    /**
    028     * Enum corresponding to the various Exception Class arrays, used by
    029     * {@link ExceptionConst#createExceptions(EXCS, Class...)}
    030     */
    031    public enum EXCS {
    032        EXCS_CLASS_AND_INTERFACE_RESOLUTION, EXCS_FIELD_AND_METHOD_RESOLUTION, EXCS_INTERFACE_METHOD_RESOLUTION, EXCS_STRING_RESOLUTION, EXCS_ARRAY_EXCEPTION,
    033    }
    034
    035    /**
    036     * The mother of all exceptions
    037     */
    038    public static final Class<Throwable> THROWABLE = Throwable.class;
    039
    040    /**
    041     * Super class of any run-time exception
    042     */
    043    public static final Class<RuntimeException> RUNTIME_EXCEPTION = RuntimeException.class;
    044
    045    /**
    046     * Super class of any linking exception (aka Linkage Error)
    047     */
    048    public static final Class<LinkageError> LINKING_EXCEPTION = LinkageError.class;
    049    /**
    050     * Linking Exceptions
    051     */
    052    public static final Class<ClassCircularityError> CLASS_CIRCULARITY_ERROR = ClassCircularityError.class;
    053    public static final Class<ClassFormatError> CLASS_FORMAT_ERROR = ClassFormatError.class;
    054    public static final Class<ExceptionInInitializerError> EXCEPTION_IN_INITIALIZER_ERROR = ExceptionInInitializerError.class;
    055    public static final Class<IncompatibleClassChangeError> INCOMPATIBLE_CLASS_CHANGE_ERROR = IncompatibleClassChangeError.class;
    056    public static final Class<AbstractMethodError> ABSTRACT_METHOD_ERROR = AbstractMethodError.class;
    057    public static final Class<IllegalAccessError> ILLEGAL_ACCESS_ERROR = IllegalAccessError.class;
    058    public static final Class<InstantiationError> INSTANTIATION_ERROR = InstantiationError.class;
    059    public static final Class<NoSuchFieldError> NO_SUCH_FIELD_ERROR = NoSuchFieldError.class;
    060    public static final Class<NoSuchMethodError> NO_SUCH_METHOD_ERROR = NoSuchMethodError.class;
    061    public static final Class<NoClassDefFoundError> NO_CLASS_DEF_FOUND_ERROR = NoClassDefFoundError.class;
    062    public static final Class<UnsatisfiedLinkError> UNSATISFIED_LINK_ERROR = UnsatisfiedLinkError.class;
    063
    064    public static final Class<VerifyError> VERIFY_ERROR = VerifyError.class;
    065    /* UnsupportedClassVersionError is new in JDK 1.2 */
    066//    public static final Class UnsupportedClassVersionError = UnsupportedClassVersionError.class;
    067    /**
    068     * Run-Time Exceptions
    069     */
    070    public static final Class<NullPointerException> NULL_POINTER_EXCEPTION = NullPointerException.class;
    071    public static final Class<ArrayIndexOutOfBoundsException> ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION = ArrayIndexOutOfBoundsException.class;
    072    public static final Class<ArithmeticException> ARITHMETIC_EXCEPTION = ArithmeticException.class;
    073    public static final Class<NegativeArraySizeException> NEGATIVE_ARRAY_SIZE_EXCEPTION = NegativeArraySizeException.class;
    074    public static final Class<ClassCastException> CLASS_CAST_EXCEPTION = ClassCastException.class;
    075
    076    public static final Class<IllegalMonitorStateException> ILLEGAL_MONITOR_STATE = IllegalMonitorStateException.class;
    077    /**
    078     * Pre-defined exception arrays according to chapters 5.1-5.4 of the Java Virtual Machine Specification
    079     */
    080    private static final Class<?>[] EXCS_CLASS_AND_INTERFACE_RESOLUTION = {NO_CLASS_DEF_FOUND_ERROR, CLASS_FORMAT_ERROR, VERIFY_ERROR, ABSTRACT_METHOD_ERROR,
    081        EXCEPTION_IN_INITIALIZER_ERROR, ILLEGAL_ACCESS_ERROR}; // Chapter 5.1
    082
    083    private static final Class<?>[] EXCS_FIELD_AND_METHOD_RESOLUTION = {NO_SUCH_FIELD_ERROR, ILLEGAL_ACCESS_ERROR, NO_SUCH_METHOD_ERROR}; // Chapter 5.2
    084
    085    /**
    086     * Empty array.
    087     */
    088    private static final Class<?>[] EXCS_INTERFACE_METHOD_RESOLUTION = new Class[0]; // Chapter 5.3 (as below)
    089
    090    /**
    091     * Empty array.
    092     */
    093    private static final Class<?>[] EXCS_STRING_RESOLUTION = new Class[0];
    094
    095    // Chapter 5.4 (no errors but the ones that _always_ could happen! How stupid.)
    096    private static final Class<?>[] EXCS_ARRAY_EXCEPTION = {NULL_POINTER_EXCEPTION, ARRAY_INDEX_OUT_OF_BOUNDS_EXCEPTION};
    097
    098    /**
    099     * Creates a copy of the specified Exception Class array combined with any additional Exception classes.
    100     *
    101     * @param type the basic array type
    102     * @param extraClasses additional classes, if any
    103     * @return the merged array
    104     */
    105    public static Class<?>[] createExceptions(final EXCS type, final Class<?>... extraClasses) {
    106        switch (type) {
    107        case EXCS_CLASS_AND_INTERFACE_RESOLUTION:
    108            return mergeExceptions(EXCS_CLASS_AND_INTERFACE_RESOLUTION, extraClasses);
    109        case EXCS_ARRAY_EXCEPTION:
    110            return mergeExceptions(EXCS_ARRAY_EXCEPTION, extraClasses);
    111        case EXCS_FIELD_AND_METHOD_RESOLUTION:
    112            return mergeExceptions(EXCS_FIELD_AND_METHOD_RESOLUTION, extraClasses);
    113        case EXCS_INTERFACE_METHOD_RESOLUTION:
    114            return mergeExceptions(EXCS_INTERFACE_METHOD_RESOLUTION, extraClasses);
    115        case EXCS_STRING_RESOLUTION:
    116            return mergeExceptions(EXCS_STRING_RESOLUTION, extraClasses);
    117        default:
    118            throw new AssertionError("Cannot happen; unexpected enum value: " + type);
    119        }
    120    }
    121
    122    // helper method to merge exception class arrays
    123    private static Class<?>[] mergeExceptions(final Class<?>[] input, final Class<?>... extraClasses) {
    124        final int extraLen = extraClasses == null ? 0 : extraClasses.length;
    125        final Class<?>[] excs = new Class<?>[input.length + extraLen];
    126        System.arraycopy(input, 0, excs, 0, input.length);
    127        if (extraLen > 0) {
    128            System.arraycopy(extraClasses, 0, excs, input.length, extraLen);
    129        }
    130        return excs;
    131    }
    132
    133}