/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 com.navercorp.pinpoint.rpc.util;
import java.util.HashMap;
import java.util.Map;
/**
* <p>Operates on classes without using reflection.</p>
*
* <p>This class handles invalid <code>null</code> inputs as best it can.
* Each method documents its behaviour in more detail.</p>
*
* <p>The notion of a <code>canonical name</code> includes the human
* readable name for the type, for example <code>int[]</code>. The
* non-canonical method variants work with the JVM names, such as
* <code>[I</code>. </p>
*
* @author Apache Software Foundation
* @author Gary Gregory
* @author Norm Deane
* @author Alban Peignier
* @author Tomasz Blachowicz
* @since 2.0
* @version $Id: ClassUtils.java 907121 2010-02-05 22:53:21Z mbenson $
*/
public class ClassUtils {
private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<Class<?>, Class<?>>();
static {
primitiveWrapperMap.put(Boolean.TYPE, Boolean.class);
primitiveWrapperMap.put(Byte.TYPE, Byte.class);
primitiveWrapperMap.put(Character.TYPE, Character.class);
primitiveWrapperMap.put(Short.TYPE, Short.class);
primitiveWrapperMap.put(Integer.TYPE, Integer.class);
primitiveWrapperMap.put(Long.TYPE, Long.class);
primitiveWrapperMap.put(Double.TYPE, Double.class);
primitiveWrapperMap.put(Float.TYPE, Float.class);
primitiveWrapperMap.put(Void.TYPE, Void.TYPE);
}
private static final Map<Class, Class> wrapperPrimitiveMap = new HashMap<Class, Class>();
static {
for (Object o : primitiveWrapperMap.keySet()) {
Class primitiveClass = (Class) o;
Class wrapperClass = primitiveWrapperMap.get(primitiveClass);
if (!primitiveClass.equals(wrapperClass)) {
wrapperPrimitiveMap.put(wrapperClass, primitiveClass);
}
}
}
// Is assignable
// ----------------------------------------------------------------------
/**
* <p>Checks if an array of Classes can be assigned to another array of Classes.</p>
*
* <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each
* Class pair in the input arrays. It can be used to check if a set of arguments
* (the first parameter) are suitably compatible with a set of method parameter types
* (the second parameter).</p>
*
* <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this
* method takes into account widenings of primitive classes and
* <code>null</code>s.</p>
*
* <p>Primitive widenings allow an int to be assigned to a <code>long</code>,
* <code>float</code> or <code>double</code>. This method returns the correct
* result for these cases.</p>
*
* <p><code>Null</code> may be assigned to any reference type. This method will
* return <code>true</code> if <code>null</code> is passed in and the toClass is
* non-primitive.</p>
*
* <p>Specifically, this method tests whether the type represented by the
* specified <code>Class</code> parameter can be converted to the type
* represented by this <code>Class</code> object via an identity conversion
* widening primitive or widening reference conversion. See
* <em><a href="http://java.sun.com/docs/books/jls/">The Java Language Specification</a></em>,
* sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
*
* @param classArray the array of Classes to check, may be <code>null</code>
* @param toClassArray the array of Classes to try to assign into, may be <code>null</code>
* @return <code>true</code> if assignment possible
*/
public static boolean isAssignable(Class cls, Class toClass) {
return isAssignable(cls, toClass, true);
}
/**
* <p>Checks if an array of Classes can be assigned to another array of Classes.</p>
*
* <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each
* Class pair in the input arrays. It can be used to check if a set of arguments
* (the first parameter) are suitably compatible with a set of method parameter types
* (the second parameter).</p>
*
* <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this
* method takes into account widenings of primitive classes and
* <code>null</code>s.</p>
*
* <p>Primitive widenings allow an int to be assigned to a <code>long</code>,
* <code>float</code> or <code>double</code>. This method returns the correct
* result for these cases.</p>
*
* <p><code>Null</code> may be assigned to any reference type. This method will
* return <code>true</code> if <code>null</code> is passed in and the toClass is
* non-primitive.</p>
*
* <p>Specifically, this method tests whether the type represented by the
* specified <code>Class</code> parameter can be converted to the type
* represented by this <code>Class</code> object via an identity conversion
* widening primitive or widening reference conversion. See
* <em><a href="http://java.sun.com/docs/books/jls/">The Java Language Specification</a></em>,
* sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
*
* @param classArray the array of Classes to check, may be <code>null</code>
* @param toClassArray the array of Classes to try to assign into, may be <code>null</code>
* @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
* @return <code>true</code> if assignment possible
* @since 2.5
*/
public static boolean isAssignable(Class<?> cls, Class<?> toClass, boolean autoboxing) {
if (toClass == null) {
return false;
}
// have to check for null, as isAssignableFrom doesn't
if (cls == null) {
return !(toClass.isPrimitive());
}
// autoboxing:
if (autoboxing) {
if (cls.isPrimitive() && !toClass.isPrimitive()) {
cls = primitiveToWrapper(cls);
if (cls == null) {
return false;
}
}
if (toClass.isPrimitive() && !cls.isPrimitive()) {
cls = wrapperToPrimitive(cls);
if (cls == null) {
return false;
}
}
}
if (cls.equals(toClass)) {
return true;
}
if (cls.isPrimitive()) {
if (toClass.isPrimitive() == false) {
return false;
}
if (Integer.TYPE.equals(cls)) {
return Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
}
if (Long.TYPE.equals(cls)) {
return Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
}
if (Boolean.TYPE.equals(cls)) {
return false;
}
if (Double.TYPE.equals(cls)) {
return false;
}
if (Float.TYPE.equals(cls)) {
return Double.TYPE.equals(toClass);
}
if (Character.TYPE.equals(cls)) {
return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
}
if (Short.TYPE.equals(cls)) {
return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
}
if (Byte.TYPE.equals(cls)) {
return Short.TYPE.equals(toClass) || Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
|| Double.TYPE.equals(toClass);
}
// should never get here
return false;
}
return toClass.isAssignableFrom(cls);
}
/**
* <p>Converts the specified primitive Class object to its corresponding
* wrapper Class object.</p>
*
* <p>NOTE: From v2.2, this method handles <code>Void.TYPE</code>,
* returning <code>Void.TYPE</code>.</p>
*
* @param cls the class to convert, may be null
* @return the wrapper class for <code>cls</code> or <code>cls</code> if
* <code>cls</code> is not a primitive. <code>null</code> if null input.
* @since 2.1
*/
public static Class primitiveToWrapper(Class cls) {
Class convertedClass = cls;
if (cls != null && cls.isPrimitive()) {
convertedClass = primitiveWrapperMap.get(cls);
}
return convertedClass;
}
/**
* <p>Converts the specified array of primitive Class objects to an array of
* its corresponding wrapper Class objects.</p>
*
* @param classes the class array to convert, may be null or empty
* @return an array which contains for each given class, the wrapper class or
* the original class if class is not a primitive. <code>null</code> if null input.
* Empty array if an empty array passed in.
* @since 2.1
*/
public static Class wrapperToPrimitive(Class cls) {
return wrapperPrimitiveMap.get(cls);
}
public static String simpleClassNameAndHashCodeString(Object object) {
String simpleClassName = simpleClassName(object);
if (object == null) {
return simpleClassName;
} else {
return simpleClassName + "@" + Integer.toHexString(object.hashCode());
}
}
public static String simpleClassName(Object object) {
if (object == null) {
return "null_object";
}
Class clazz = object.getClass();
Package pkg = clazz.getPackage();
if (pkg != null) {
return clazz.getName().substring(pkg.getName().length() + 1);
} else {
return clazz.getName();
}
}
}