net.sourceforge.atunes.utils.ReflectionUtils.java Source code

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Here is the source code for net.sourceforge.atunes.utils.ReflectionUtils.java

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/*
 * aTunes
 * Copyright (C) Alex Aranda, Sylvain Gaudard and contributors
 *
 * See http://www.atunes.org/wiki/index.php?title=Contributing for information about contributors
 *
 * http://www.atunes.org
 * http://sourceforge.net/projects/atunes
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

package net.sourceforge.atunes.utils;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Map;

import org.apache.commons.beanutils.PropertyUtils;

/**
 * Utilities for reflection
 * 
 * @author alex
 * 
 */
public final class ReflectionUtils {

    private ReflectionUtils() {
    }

    /**
     * Returns class or null if any exception happens
     * 
     * @param className
     * @return
     */
    public static Class<?> getClass(final String className) {
        try {
            return Class.forName(className);
        } catch (ClassNotFoundException e) {
            Logger.error(e);
        }
        return null;
    }

    /**
     * Creates a new instance of a class with a default constructor or returns
     * null if any exception happens
     * 
     * @param className
     * @return
     */
    public static Object newInstance(final String className) {
        Class<?> clazz;
        try {
            clazz = Class.forName(className);
            return clazz.getConstructor((Class[]) null).newInstance((Object[]) null);
        } catch (ClassNotFoundException e) {
            Logger.error(e);
        } catch (IllegalArgumentException e) {
            Logger.error(e);
        } catch (SecurityException e) {
            Logger.error(e);
        } catch (InstantiationException e) {
            Logger.error(e);
        } catch (IllegalAccessException e) {
            Logger.error(e);
        } catch (InvocationTargetException e) {
            Logger.error(e);
        } catch (NoSuchMethodException e) {
            Logger.error(e);
        }
        return null;
    }

    /**
     * Returns method object or null if any error happens
     * 
     * @param clazz
     * @param methodName
     * @param arguments
     * @return
     */
    public static Method getMethod(final Class<?> clazz, final String methodName, final Class<?>... arguments) {
        try {
            return clazz.getDeclaredMethod(methodName, arguments);
        } catch (IllegalArgumentException e) {
            Logger.error(e);
        } catch (SecurityException e) {
            Logger.error(e);
        } catch (NoSuchMethodException e) {
            Logger.error(e);
        }
        return null;
    }

    /**
     * Invokes a method of an object with given arguments
     * 
     * @param instance
     * @param method
     * @param arguments
     * @return result of invoke
     */
    public static Object invoke(final Object instance, final Method method, final Object... arguments) {
        if (method != null) {
            try {
                return method.invoke(instance, arguments);
            } catch (IllegalArgumentException e) {
                Logger.error(e);
            } catch (IllegalAccessException e) {
                Logger.error(e);
            } catch (InvocationTargetException e) {
                Logger.error(e);
            }
        }
        return null;
    }

    /**
     * Returns type arguments of a clazz
     * 
     * @param clazz
     * @return
     */
    public static Type[] getTypeArgumentsOfParameterizedType(final Class<?> clazz) {
        return ((ParameterizedType) clazz.getGenericSuperclass()).getActualTypeArguments();
    }

    /**
     * Returns map with properties and values of given object
     * 
     * @param bean
     * @return
     */
    @SuppressWarnings("unchecked")
    public static Map<String, String> describe(final Object bean) {
        try {
            Map<String, String> description = PropertyUtils.describe(bean);
            description.remove("class");
            return description;
        } catch (IllegalAccessException e) {
            Logger.error(e);
        } catch (InvocationTargetException e) {
            Logger.error(e);
        } catch (NoSuchMethodException e) {
            Logger.error(e);
        }
        return null;
    }
}