/*
* 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 org.apache.openjpa.lib.util;
/**
* Various helper methods to deal with Classes
*/
public final class ClassUtil {
private static final Object[][] _codes = new Object[][]{
{byte.class, "byte", "B"},
{char.class, "char", "C"},
{double.class, "double", "D"},
{float.class, "float", "F"},
{int.class, "int", "I"},
{long.class, "long", "J"},
{short.class, "short", "S"},
{boolean.class, "boolean", "Z"},
{void.class, "void", "V"}
};
private ClassUtil() {
}
/**
* Return the class for the given string, correctly handling
* primitive types. If the given class loader is null, the context
* loader of the current thread will be used.
*
* @throws RuntimeException on load error
* @author Abe White, taken from the Serp project
*/
public static Class toClass(String str, ClassLoader loader) {
return toClass(str, false, loader);
}
/**
* Return the class for the given string, correctly handling
* primitive types. If the given class loader is null, the context
* loader of the current thread will be used.
*
* @throws RuntimeException on load error
* @author Abe White, taken from the Serp project
*/
public static Class toClass(String str, boolean resolve,
ClassLoader loader) {
if (str == null) {
throw new NullPointerException("str == null");
}
// array handling
int dims = 0;
while (str.endsWith("[]")) {
dims++;
str = str.substring(0, str.length() - 2);
}
// check against primitive types
boolean primitive = false;
if (str.indexOf('.') == -1) {
for (int i = 0; !primitive && (i < _codes.length); i++) {
if (_codes[i][1].equals(str)) {
if (dims == 0) {
return (Class) _codes[i][0];
}
str = (String) _codes[i][2];
primitive = true;
}
}
}
if (dims > 0) {
StringBuilder buf = new StringBuilder(str.length() + dims + 2);
for (int i = 0; i < dims; i++) {
buf.append('[');
}
if (!primitive) {
buf.append('L');
}
buf.append(str);
if (!primitive) {
buf.append(';');
}
str = buf.toString();
}
if (loader == null) {
loader = Thread.currentThread().getContextClassLoader();
}
try {
return Class.forName(str, resolve, loader);
}
catch (ClassNotFoundException | NoClassDefFoundError e) {
throw new IllegalArgumentException(e.getMessage());
}
}
/**
* Return only the class name, without package.
*/
public static String getClassName(Class cls) {
if (cls == null) {
return null;
}
return getClassName(cls.getName());
}
/**
* Return only the class name.
*/
public static String getClassName(String fullName) {
if (fullName == null) {
return null;
}
if (fullName.isEmpty()) {
return fullName;
}
int dims = getArrayDimensions(fullName);
if (dims > 0) {
if (fullName.length() == dims + 1) {
String classCode = fullName.substring(dims);
for (int i = 0; i < _codes.length; i++) {
if (_codes[i][2].equals(classCode)) {
fullName = (String)_codes[i][1];
break;
}
}
}
else {
if (fullName.charAt(fullName.length()-1) == ';') {
fullName = fullName.substring(dims + 1, fullName.length() - 1);
}
else {
fullName = fullName.substring(dims + 1);
}
}
}
int lastDot = fullName.lastIndexOf('.');
String simpleName = lastDot > -1 ? fullName.substring(lastDot + 1) : fullName;
if (dims > 0) {
StringBuilder sb = new StringBuilder(simpleName.length() + dims * 2);
sb.append(simpleName);
for (int i = 0; i < dims; i++) {
sb.append("[]");
}
simpleName = sb.toString();
}
return simpleName;
}
private static int getArrayDimensions(String fullClassName) {
int dims = 0;
while (fullClassName.charAt(dims) == '[') {
dims++;
}
return dims;
}
/**
* Return only the package, or empty string if none.
*/
public static String getPackageName(Class cls) {
return (cls == null) ? null : getPackageName(cls.getName());
}
/**
* Return only the package, or empty string if none.
*/
public static String getPackageName(String fullName) {
if (fullName == null) {
return null;
}
if (fullName.isEmpty()) {
return fullName;
}
int dims = getArrayDimensions(fullName);
if (dims > 0) {
if (fullName.length() == dims + 1) {
// don't care, it's a primitive
return "";
}
else {
fullName = fullName.substring(dims + 1);
}
}
int lastDot = fullName.lastIndexOf('.');
return lastDot > -1 ? fullName.substring(0, lastDot) : "";
}
}