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;}}