常用到的类实例化

/**
 * <p>类的描述：</p>
 * @author gao.tang
 * @version 1.0
 * @date 2011-3-7 下午02:12:31
 */
public class LoadExtClassUtil {
	
	public static boolean isNull(String param){
		return (param == null || "".equals(param));
	}
	
	public static Object getInstance(String extClass,String defaultExtClass){
		Object object = null;
		try {
			object = Class.forName(extClass).newInstance();
		} catch (InstantiationException e) {
			e.printStackTrace();
			try {
				object =   Class.forName(defaultExtClass).newInstance();
			} catch (InstantiationException e1) {
				e1.printStackTrace();
			} catch (IllegalAccessException e1) {
				e1.printStackTrace();
			} catch (ClassNotFoundException e1) {
				e1.printStackTrace();
			}
		} catch (IllegalAccessException e) {
			e.printStackTrace();
			try {
				object = Class.forName(defaultExtClass).newInstance();
			} catch (InstantiationException e1) {
				e1.printStackTrace();
			} catch (IllegalAccessException e1) {
				e1.printStackTrace();
			} catch (ClassNotFoundException e1) {
				e1.printStackTrace();
			}
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
			try {
				object = Class.forName(defaultExtClass).newInstance();
			} catch (InstantiationException e1) {
				e1.printStackTrace();
			} catch (IllegalAccessException e1) {
				e1.printStackTrace();
			} catch (ClassNotFoundException e1) {
				e1.printStackTrace();
			}
		}
		return object;
	}

}