com.glaf.core.util.ClassUtils.java Source code

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Here is the source code for com.glaf.core.util.ClassUtils.java

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/*
 * 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.glaf.core.util;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.apache.commons.lang3.StringUtils;

public class ClassUtils {

    private static ConcurrentMap<String, Class<?>> cache = new ConcurrentHashMap<String, Class<?>>();

    public static void addClassInCache(String className, Class<?> cls) {
        if (StringUtils.isNotEmpty(className) && cls != null) {
            ClassUtils.cache.put(className, cls);
        }
    }

    public static Class<?> classForName(String className) {
        return loadClass(className, null);
    }

    public static void clear() {
        ClassUtils.cache.clear();
    }

    @SuppressWarnings("unchecked")
    public static <T> Class<T> getClass(T o) {
        return (Class<T>) o.getClass();
    }

    public static Object instantiateClass(String className) {
        try {
            Class<?> clazz = Class.forName(className);
            return org.springframework.beans.BeanUtils.instantiateClass(clazz);
        } catch (Throwable e) {
            throw new RuntimeException("Unable to instantiate object for class '" + className + "'", e);
        }
    }

    public static Object instantiateObject(String className) {
        return instantiateObject(className, null);
    }

    public static Object instantiateObject(String className, ClassLoader classLoader) {
        Class<?> cls = ClassUtils.cache.get(className);
        if (cls == null) {
            cls = loadClass(className, classLoader);
        }
        Object object = null;
        if (cls != null) {
            try {
                object = cls.newInstance();
            } catch (Throwable e) {
                throw new RuntimeException("Unable to instantiate object for class '" + className + "'", e);
            }
        }
        return object;
    }

    public static Class<?> loadClass(String className) {
        return loadClass(className, null);
    }

    public static Class<?> loadClass(String className, ClassLoader classLoader) {
        Class<?> cls = ClassUtils.cache.get(className);
        if (cls == null) {
            try {
                cls = Class.forName(className);
            } catch (Exception e) {
            }

            if (cls == null && classLoader != null) {
                try {
                    cls = classLoader.loadClass(className);
                } catch (Exception e) {
                }
            }

            if (cls == null) {
                try {
                    cls = ClassUtils.class.getClassLoader().loadClass(className);
                } catch (Exception e) {
                }
            }

            if (cls == null) {
                try {
                    cls = Thread.currentThread().getContextClassLoader().loadClass(className);
                } catch (Exception e) {
                }
            }

            if (cls == null) {
                try {
                    cls = ClassLoader.getSystemClassLoader().loadClass(className);
                } catch (Exception e) {
                }
            }

            if (cls == null) {

            }

            if (cls != null) {
                ClassUtils.cache.put(className, cls);
            } else {
                throw new RuntimeException("Unable to load class '" + className + "'");
            }
        }

        return cls;
    }

    public static Object newObject(Class<?> clazz) {
        try {
            return org.springframework.beans.BeanUtils.instantiateClass(clazz);
        } catch (Throwable e) {
            throw new RuntimeException("Unable to instantiate object for class '" + clazz.getName() + "'", e);
        }
    }

    public static void removeClassFromCache(String className) {
        ClassUtils.cache.remove(className);
    }

    private ClassUtils() {

    }

}