org.covito.kit.utility.ClassUtil.java Source code

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Here is the source code for org.covito.kit.utility.ClassUtil.java

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/*
 * Copyright 2010-2014  All rights reserved.
 *
 * 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.covito.kit.utility;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;

import org.apache.commons.lang.ClassUtils;

/**
 * Class
 * <p>
 * ??
 * </p>
 * 
 * @author covito
 * @version [v1.0, 2014626]
 */
public class ClassUtil extends ClassUtils {

    public static URL getClassLocation(final String clsName) {
        if (clsName == null) {
            return null;
        }
        Class cls = null;
        try {
            cls = Class.forName(clsName);
        } catch (Exception e) {
            return null;
        }
        URL result = null;
        final String clsAsResource = cls.getName().replace('.', '/').concat(".class");
        final ProtectionDomain pd = cls.getProtectionDomain();
        // java.lang.Class contract does not specify if 'pd' can ever be null;
        // it is not the case for Sun's implementations, but guard against null
        // just in case:
        if (pd != null) {
            final CodeSource cs = pd.getCodeSource();
            // 'cs' can be null depending on the classloader behavior:
            if (cs != null)
                result = cs.getLocation();
            if (result != null) {
                // Convert a code source location into a full class file
                // location
                // for some common cases:
                if ("file".equals(result.getProtocol())) {
                    try {
                        if (result.toExternalForm().endsWith(".jar") || result.toExternalForm().endsWith(".zip"))
                            result = new URL(
                                    "jar:".concat(result.toExternalForm()).concat("!/").concat(clsAsResource));
                        else if (new File(result.getFile()).isDirectory()) {
                            result = new URL(result, clsAsResource);
                        }
                    } catch (MalformedURLException ignore) {
                    }
                }
            }
        }
        if (result == null) {
            // Try to find 'cls' definition as a resource; this is not
            // documentd to be legal, but Sun's implementations seem to //allow
            // this:
            final ClassLoader clsLoader = cls.getClassLoader();
            result = clsLoader != null ? clsLoader.getResource(clsAsResource)
                    : ClassLoader.getSystemResource(clsAsResource);
        }
        return result;
    }

    public static void main(String[] args) {
        System.out.println(getClassLocation("org.apache.commons.io.EndianUtils"));
    }
}