org.jboss.classfilewriter.util.DescriptorUtils Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
*
* Copyright 2012 Red Hat, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.classfilewriter.util;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
/**
* Utility class for working with method descriptors
*
* @author Stuart Douglas
*/
public class DescriptorUtils {
static final String VOID_CLASS_DESCRIPTOR = "V";
static final String BYTE_CLASS_DESCRIPTOR = "B";
static final String CHAR_CLASS_DESCRIPTOR = "C";
static final String DOUBLE_CLASS_DESCRIPTOR = "D";
static final String FLOAT_CLASS_DESCRIPTOR = "F";
static final String INT_CLASS_DESCRIPTOR = "I";
static final String LONG_CLASS_DESCRIPTOR = "J";
static final String SHORT_CLASS_DESCRIPTOR = "S";
static final String BOOLEAN_CLASS_DESCRIPTOR = "Z";
/**
* Changes a class name to the internal form suitable for use in a descriptor string.
*
* e.g. java.lang.String => Ljava/lang/String;
*/
public static String makeDescriptor(String className) {
String repl = className.replace(".", "/");
return 'L' + repl + ';';
}
public static String makeDescriptor(Class c) {
if (void.class.equals(c)) {
return VOID_CLASS_DESCRIPTOR;
} else if (byte.class.equals(c)) {
return BYTE_CLASS_DESCRIPTOR;
} else if (char.class.equals(c)) {
return CHAR_CLASS_DESCRIPTOR;
} else if (double.class.equals(c)) {
return DOUBLE_CLASS_DESCRIPTOR;
} else if (float.class.equals(c)) {
return FLOAT_CLASS_DESCRIPTOR;
} else if (int.class.equals(c)) {
return INT_CLASS_DESCRIPTOR;
} else if (long.class.equals(c)) {
return LONG_CLASS_DESCRIPTOR;
} else if (short.class.equals(c)) {
return SHORT_CLASS_DESCRIPTOR;
} else if (boolean.class.equals(c)) {
return BOOLEAN_CLASS_DESCRIPTOR;
} else if (c.isArray()) {
return c.getName().replace(".", "/");
} else
// normal object
{
return makeDescriptor(c.getName());
}
}
public static String makeDescriptor(Constructor c) {
StringBuilder desc = new StringBuilder("(");
for (Class p : c.getParameterTypes()) {
desc.append(DescriptorUtils.makeDescriptor(p));
}
desc.append(")");
desc.append("V");
return desc.toString();
}
/**
* returns an array of String representations of the parameter types. Primitives are returned as their native
* representations, while clases are returned in the internal descriptor form e.g. Ljava/lang/Integer;
*/
public static String[] parameterDescriptors(String methodDescriptor) {
int i = 1; // char 0 is a '('
List ret = new ArrayList();
int arraystart = -1;
while (methodDescriptor.charAt(i) != ')') {
String type = null;
if (methodDescriptor.charAt(i) == '[') {
if (arraystart == -1) {
arraystart = i;
}
} else {
if (methodDescriptor.charAt(i) == 'L') {
int start = i;
i++;
while (methodDescriptor.charAt(i) != ';') {
++i;
}
if (arraystart == -1) {
type = methodDescriptor.substring(start, i + 1);
} else {
type = methodDescriptor.substring(arraystart, i + 1);
}
} else {
if (arraystart == -1) {
type = methodDescriptor.charAt(i) + "";
} else {
type = methodDescriptor.substring(arraystart, i + 1);
}
}
arraystart = -1;
ret.add(type);
}
++i;
}
String[] r = new String[ret.size()];
for (int j = 0; j < ret.size(); ++j) {
r[j] = ret.get(j);
}
return r;
}
public static String[] parameterDescriptors(Method m) {
return parameterDescriptors(m.getParameterTypes());
}
public static String[] parameterDescriptors(Class[] parameters) {
String[] ret = new String[parameters.length];
for (int i = 0; i < ret.length; ++i) {
ret[i] = DescriptorUtils.makeDescriptor(parameters[i]);
}
return ret;
}
public static String returnType(String methodDescriptor) {
return methodDescriptor.substring(methodDescriptor.lastIndexOf(')') + 1, methodDescriptor.length());
}
/**
* returns true if the descriptor represents a primitive type
*/
public static boolean isPrimitive(String descriptor) {
if (descriptor.length() == 1) {
return true;
}
return false;
}
/**
* returns true if the descriptor represents a long or a double
*/
public static boolean isWide(String descriptor) {
if (!isPrimitive(descriptor)) {
return false;
}
char c = descriptor.charAt(0);
if (c == 'D' || c == 'J') {
return true;
}
return false;
}
/**
* returns true if the class represents a long or a double
*/
public static boolean isWide(Class cls) {
return cls == double.class || cls == long.class;
}
public static String methodDescriptor(Method m) {
StringBuilder desc = new StringBuilder("(");
for (Class p : m.getParameterTypes()) {
desc.append(DescriptorUtils.makeDescriptor(p));
}
desc.append(")");
desc.append(DescriptorUtils.makeDescriptor(m.getReturnType()));
return desc.toString();
}
public static String methodDescriptor(String[] parameters, String returnType) {
StringBuilder desc = new StringBuilder("(");
for (String p : parameters) {
desc.append(p);
}
desc.append(")");
desc.append(returnType);
return desc.toString();
}
/**
* performs basic validation on a descriptor
*/
public static String validateDescriptor(String descriptor) {
if (descriptor.length() == 0) {
throw new RuntimeException("descriptors may not be empty");
}
if (descriptor.length() > 1) {
if (descriptor.startsWith("L")) {
if (!descriptor.endsWith(";")) {
throw new RuntimeException(descriptor + " is not a valid descriptor");
}
} else if (descriptor.startsWith("[")) {
} else {
throw new RuntimeException(descriptor + " is not a valid descriptor");
}
} else {
char type = descriptor.charAt(0);
switch (type) {
case 'I':
case 'Z':
case 'S':
case 'B':
case 'F':
case 'D':
case 'V':
case 'J':
case 'C':
break;
default:
throw new RuntimeException(descriptor + " is not a valid descriptor");
}
}
return descriptor;
}
}