Java tutorial
// ASM: a very small and fast Java bytecode manipulation framework // Copyright (c) 2000-2011 INRIA, France Telecom // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // 1. Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // 2. Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // 3. Neither the name of the copyright holders nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF // THE POSSIBILITY OF SUCH DAMAGE. package org.objectweb.asm.signature; import org.objectweb.asm.Opcodes; /** * A visitor to visit a generic signature. The methods of this interface must be called in one of * the three following orders (the last one is the only valid order for a {@link SignatureVisitor} * that is returned by a method of this interface): * * <ul> * <li><i>ClassSignature</i> = ( {@code visitFormalTypeParameter} {@code visitClassBound}? {@code * visitInterfaceBound}* )* ({@code visitSuperclass} {@code visitInterface}* ) * <li><i>MethodSignature</i> = ( {@code visitFormalTypeParameter} {@code visitClassBound}? {@code * visitInterfaceBound}* )* ({@code visitParameterType}* {@code visitReturnType} {@code * visitExceptionType}* ) * <li><i>TypeSignature</i> = {@code visitBaseType} | {@code visitTypeVariable} | {@code * visitArrayType} | ( {@code visitClassType} {@code visitTypeArgument}* ( {@code * visitInnerClassType} {@code visitTypeArgument}* )* {@code visitEnd} ) ) * </ul> * * @author Thomas Hallgren * @author Eric Bruneton */ public abstract class SignatureVisitor { /** Wildcard for an "extends" type argument. */ public static final char EXTENDS = '+'; /** Wildcard for a "super" type argument. */ public static final char SUPER = '-'; /** Wildcard for a normal type argument. */ public static final char INSTANCEOF = '='; /** * The ASM API version implemented by this visitor. The value of this field must be one of {@link * Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}. */ protected final int api; /** * Constructs a new {@link SignatureVisitor}. * * @param api the ASM API version implemented by this visitor. Must be one of {@link * Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}. */ public SignatureVisitor(final int api) { if (api != Opcodes.ASM7 && api != Opcodes.ASM6 && api != Opcodes.ASM5 && api != Opcodes.ASM4 && api != Opcodes.ASM8_EXPERIMENTAL) { throw new IllegalArgumentException("Unsupported api " + api); } this.api = api; } /** * Visits a formal type parameter. * * @param name the name of the formal parameter. */ public void visitFormalTypeParameter(final String name) { } /** * Visits the class bound of the last visited formal type parameter. * * @return a non null visitor to visit the signature of the class bound. */ public SignatureVisitor visitClassBound() { return this; } /** * Visits an interface bound of the last visited formal type parameter. * * @return a non null visitor to visit the signature of the interface bound. */ public SignatureVisitor visitInterfaceBound() { return this; } /** * Visits the type of the super class. * * @return a non null visitor to visit the signature of the super class type. */ public SignatureVisitor visitSuperclass() { return this; } /** * Visits the type of an interface implemented by the class. * * @return a non null visitor to visit the signature of the interface type. */ public SignatureVisitor visitInterface() { return this; } /** * Visits the type of a method parameter. * * @return a non null visitor to visit the signature of the parameter type. */ public SignatureVisitor visitParameterType() { return this; } /** * Visits the return type of the method. * * @return a non null visitor to visit the signature of the return type. */ public SignatureVisitor visitReturnType() { return this; } /** * Visits the type of a method exception. * * @return a non null visitor to visit the signature of the exception type. */ public SignatureVisitor visitExceptionType() { return this; } /** * Visits a signature corresponding to a primitive type. * * @param descriptor the descriptor of the primitive type, or 'V' for {@code void} . */ public void visitBaseType(final char descriptor) { } /** * Visits a signature corresponding to a type variable. * * @param name the name of the type variable. */ public void visitTypeVariable(final String name) { } /** * Visits a signature corresponding to an array type. * * @return a non null visitor to visit the signature of the array element type. */ public SignatureVisitor visitArrayType() { return this; } /** * Starts the visit of a signature corresponding to a class or interface type. * * @param name the internal name of the class or interface. */ public void visitClassType(final String name) { } /** * Visits an inner class. * * @param name the local name of the inner class in its enclosing class. */ public void visitInnerClassType(final String name) { } /** Visits an unbounded type argument of the last visited class or inner class type. */ public void visitTypeArgument() { } /** * Visits a type argument of the last visited class or inner class type. * * @param wildcard '+', '-' or '='. * @return a non null visitor to visit the signature of the type argument. */ public SignatureVisitor visitTypeArgument(final char wildcard) { return this; } /** Ends the visit of a signature corresponding to a class or interface type. */ public void visitEnd() { } }