Java tutorial
/*** * ASM: a very small and fast Java bytecode manipulation framework * Copyright (c) 2000-2007 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 com.google.gwt.dev.asm.commons; import com.google.gwt.dev.asm.Type; import java.util.HashMap; import java.util.Map; /** * A named method descriptor. * * @author Juozas Baliuka * @author Chris Nokleberg * @author Eric Bruneton */ public class Method { /** * The method name. */ private final String name; /** * The method descriptor. */ private final String desc; /** * Maps primitive Java type names to their descriptors. */ private static final Map DESCRIPTORS; static { DESCRIPTORS = new HashMap(); DESCRIPTORS.put("void", "V"); DESCRIPTORS.put("byte", "B"); DESCRIPTORS.put("char", "C"); DESCRIPTORS.put("double", "D"); DESCRIPTORS.put("float", "F"); DESCRIPTORS.put("int", "I"); DESCRIPTORS.put("long", "J"); DESCRIPTORS.put("short", "S"); DESCRIPTORS.put("boolean", "Z"); } /** * Creates a new {@link Method}. * * @param name the method's name. * @param desc the method's descriptor. */ public Method(final String name, final String desc) { this.name = name; this.desc = desc; } /** * Creates a new {@link Method}. * * @param name the method's name. * @param returnType the method's return type. * @param argumentTypes the method's argument types. */ public Method(final String name, final Type returnType, final Type[] argumentTypes) { this(name, Type.getMethodDescriptor(returnType, argumentTypes)); } /** * Returns a {@link Method} corresponding to the given Java method * declaration. * * @param method a Java method declaration, without argument names, of the * form "returnType name (argumentType1, ... argumentTypeN)", where * the types are in plain Java (e.g. "int", "float", * "java.util.List", ...). Classes of the java.lang package can be * specified by their unqualified name; all other classes names must * be fully qualified. * @return a {@link Method} corresponding to the given Java method * declaration. * @throws IllegalArgumentException if <code>method</code> could not get * parsed. */ public static Method getMethod(final String method) throws IllegalArgumentException { return getMethod(method, false); } /** * Returns a {@link Method} corresponding to the given Java method * declaration. * * @param method a Java method declaration, without argument names, of the * form "returnType name (argumentType1, ... argumentTypeN)", where * the types are in plain Java (e.g. "int", "float", * "java.util.List", ...). Classes of the java.lang package may be * specified by their unqualified name, depending on the * defaultPackage argument; all other classes names must be fully * qualified. * @param defaultPackage true if unqualified class names belong to the * default package, or false if they correspond to java.lang classes. * For instance "Object" means "Object" if this option is true, or * "java.lang.Object" otherwise. * @return a {@link Method} corresponding to the given Java method * declaration. * @throws IllegalArgumentException if <code>method</code> could not get * parsed. */ public static Method getMethod(final String method, final boolean defaultPackage) throws IllegalArgumentException { int space = method.indexOf(' '); int start = method.indexOf('(', space) + 1; int end = method.indexOf(')', start); if (space == -1 || start == -1 || end == -1) { throw new IllegalArgumentException(); } String returnType = method.substring(0, space); String methodName = method.substring(space + 1, start - 1).trim(); StringBuffer sb = new StringBuffer(); sb.append('('); int p; do { String s; p = method.indexOf(',', start); if (p == -1) { s = map(method.substring(start, end).trim(), defaultPackage); } else { s = map(method.substring(start, p).trim(), defaultPackage); start = p + 1; } sb.append(s); } while (p != -1); sb.append(')'); sb.append(map(returnType, defaultPackage)); return new Method(methodName, sb.toString()); } private static String map(final String type, final boolean defaultPackage) { if ("".equals(type)) { return type; } StringBuffer sb = new StringBuffer(); int index = 0; while ((index = type.indexOf("[]", index) + 1) > 0) { sb.append('['); } String t = type.substring(0, type.length() - sb.length() * 2); String desc = (String) DESCRIPTORS.get(t); if (desc != null) { sb.append(desc); } else { sb.append('L'); if (t.indexOf('.') < 0) { if (!defaultPackage) { sb.append("java/lang/"); } sb.append(t); } else { sb.append(t.replace('.', '/')); } sb.append(';'); } return sb.toString(); } /** * Returns the name of the method described by this object. * * @return the name of the method described by this object. */ public String getName() { return name; } /** * Returns the descriptor of the method described by this object. * * @return the descriptor of the method described by this object. */ public String getDescriptor() { return desc; } /** * Returns the return type of the method described by this object. * * @return the return type of the method described by this object. */ public Type getReturnType() { return Type.getReturnType(desc); } /** * Returns the argument types of the method described by this object. * * @return the argument types of the method described by this object. */ public Type[] getArgumentTypes() { return Type.getArgumentTypes(desc); } public String toString() { return name + desc; } public boolean equals(final Object o) { if (!(o instanceof Method)) { return false; } Method other = (Method) o; return name.equals(other.name) && desc.equals(other.desc); } public int hashCode() { return name.hashCode() ^ desc.hashCode(); } }