    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}