Objects.java

/**
 ** Copyright (c) 2010 Ushahidi Inc
 ** All rights reserved
 ** Contact: team@ushahidi.com
 ** Website: http://www.ushahidi.com
 **
 ** GNU Lesser General Public License Usage
 ** This file may be used under the terms of the GNU Lesser
 ** General Public License version 3 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file. Please review the following information to
 ** ensure the GNU Lesser General Public License version 3 requirements
 ** will be met: http://www.gnu.org/licenses/lgpl.html.
 **
 **
 ** If you have questions regarding the use of this file, please contact
 ** Ushahidi developers at team@ushahidi.com.
 **
 **/
package com.ushahidi.android.app.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import android.util.Log;
import android.view.InflateException;

public class Objects {

	/**
	 * Helps to avoid using {@code @SuppressWarnings( "unchecked"})} when
	 * casting to a generic type.
	 */
	@SuppressWarnings("unchecked")
	public static <T, X extends T> X cast(T o) {
		return (X) o;
	}

	public static Type[] getGenericTypes(Object obj) {
		ParameterizedType superclass = (ParameterizedType) obj.getClass()
				.getGenericSuperclass();
		return superclass.getActualTypeArguments();
	}

	public static Type getGenericType(Object obj, int index) {
		ParameterizedType superclass = (ParameterizedType) obj.getClass()
				.getGenericSuperclass();
		return superclass.getActualTypeArguments()[index];
	}

	@SuppressWarnings("unchecked")
	public static <T> T createInstance(Class<?> targetClass) {
		try {
			return (T) targetClass.newInstance();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		}
		return null;
	}

	@SuppressWarnings("unchecked")
	public static <T> T createInstance(Class type, Class constructor,
			Object... params) {
		try {
			return (T) type.getConstructor(constructor).newInstance(params);
		} catch (InstantiationException e) {
			Log.e(Objects.class.getName(), "InstantiationException", e);
		} catch (IllegalAccessException e) {
			Log.e(Objects.class.getName(), "IllegalAccessException", e);
		} catch (InvocationTargetException e) {
			Log.e(Objects.class.getName(), "InvocationTargetException", e);
		} catch (NoSuchMethodException e) {
			Log.e(Objects.class.getName(), "NoSuchMethodException", e);
		}
		return null;
	}

	@SuppressWarnings("unchecked")
	public static <T> T createInstance(Class type, Class[] constructors,
			Object... params) {
		try {
			return (T) type.getConstructor(constructors).newInstance(params);
		} catch (InstantiationException e) {
			Log.e(Objects.class.getName(), "InstantiationException", e);
		} catch (IllegalAccessException e) {
			Log.e(Objects.class.getName(), "IllegalAccessException", e);
		} catch (IllegalStateException e) {
			Log.e(Objects.class.getName(), "IllegalStateException", e);
		} catch (InvocationTargetException e) {
			Log.e(Objects.class.getName(), "InvocationTargetException", e);
			for (StackTraceElement exception : e.getStackTrace()) {
				Log.e(Objects.class.getName(),
						String.format("%s", exception.toString()));
			}
		} catch (NoSuchMethodException e) {
			Log.e(Objects.class.getName(), "NoSuchMethodException", e);
		} catch (InflateException e) {
			Log.e(Objects.class.getName(), "InflateException", e);
		}
		return null;
	}

	@SuppressWarnings("unchecked")
	public static <T> T createInstance(Type type, Class[] constructorClasses,
			Object[] constructorParams) {
		try {
			Log.i("Type", type.toString());
			if (type.getClass().getConstructors().length > 0) {
				for (Constructor construct : type.getClass().getConstructors()) {
					Log.i("Constructor", construct.toString());
				}
				Constructor<? extends Type> constructor = type.getClass()
						.getConstructor(constructorClasses);
				return (T) constructor.newInstance(constructorParams);
			} else {
				// HACK to resolve generic types losing their class information
				// at runtime
				String typeName = type.toString().replaceFirst("class ", "");
				for (Constructor construct : Class.forName(typeName)
						.getConstructors()) {
					Log.i("Constructor", construct.toString());
				}
				Constructor<? extends Type> constructor = (Constructor<? extends Type>) Class
						.forName(typeName).getConstructor(constructorClasses);
				return (T) constructor.newInstance(constructorParams);
			}
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return null;
	}

}