?? beans.java
字號:
/* java.beans.Beans Copyright (C) 1998, 1999 Free Software Foundation, Inc.This file is part of GNU Classpath.GNU Classpath is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2, or (at your option)any later version. GNU Classpath is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNUGeneral Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Classpath; see the file COPYING. If not, write to theFree Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307 USA.Linking this library statically or dynamically with other modules ismaking a combined work based on this library. Thus, the terms andconditions of the GNU General Public License cover the wholecombination.As a special exception, the copyright holders of this library give youpermission to link this library with independent modules to produce anexecutable, regardless of the license terms of these independentmodules, and to copy and distribute the resulting executable underterms of your choice, provided that you also meet, for each linkedindependent module, the terms and conditions of the license of thatmodule. An independent module is a module which is not derived fromor based on this library. If you modify this library, you may extendthis exception to your version of the library, but you are notobligated to do so. If you do not wish to do so, delete thisexception statement from your version. */package java.beans;import gnu.java.io.ClassLoaderObjectInputStream;import java.io.InputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.applet.Applet;/** * <code>Beans</code> provides some helper methods that allow the basic * operations of Bean-ness. * * @author John Keiser * @since 1.1 * @version 1.1.0, 29 Jul 1998 * */public class Beans{ static boolean designTime = false; static boolean guiAvailable = true; /** * Once again, we have a java.beans class with only * static methods that can be instantiated. When * will the madness end? :) */ public Beans() { // Do nothing here. } /** * Allows you to instantiate a Bean. This method takes * a ClassLoader from which to read the Bean and the * name of the Bean.<P> * * The Bean name should be a dotted name, like a class. * It can represent several things. Beans will search * for the Bean using the name like this:<P> * <OL> * <LI>Searches for a serialized instance of the Bean * using getResource(), mangling the Bean name by * replacing the dots with slashes and appending .ser * (for example, gnu.beans.BlahDeBlah would cause * Beans to search for gnu/beans/BlahDeBlah.ser using * getResource()).</LI> * <LI>Searches for the Bean class using the beanName, * and then instantiates it with the no-arg constructor. * At that point, if it is an Applet, it provides it * with AppletContext and AppletStub, and then calls * init().</LI> * </OL> * * @param cl the ClassLoader to use, or <CODE>null</CODE> * to use the default ClassLoader. * @param beanName the name of the Bean. * * @return the Bean. * * @XXX */ public static Object instantiate (ClassLoader cl, String beanName) throws IOException, ClassNotFoundException { Object bean; InputStream serStream; if (cl == null) { serStream = ClassLoader.getSystemResourceAsStream (beanName.replace ('.','/')+".ser"); } else { serStream = cl.getResourceAsStream (beanName.replace ('.', '/') + ".ser"); } if (serStream != null) { if(cl == null) { ObjectInputStream ois = new ObjectInputStream(serStream); bean = ois.readObject(); } else { ClassLoaderObjectInputStream ois = new ClassLoaderObjectInputStream (serStream, cl); bean = ois.readObject(); } } else if(cl == null) { Class beanClass = Class.forName(beanName); try { bean = beanClass.newInstance(); } catch(IllegalAccessException E) { bean = null; } catch(InstantiationException E) { bean = null; } } else { Class beanClass = cl.loadClass(beanName); try { bean = beanClass.newInstance(); } catch(IllegalAccessException E) { bean = null; } catch(InstantiationException E) { bean = null; } } if(bean instanceof Applet) { Applet a = (Applet)bean; //a.setAppletContext(???); //a.setStub(???); if(serStream == null) { a.init(); } } return bean; } /** * Get the Bean as a different class type. * This should be used instead of casting to get a new * type view of a Bean, because in the future there may * be new types of Bean, even Beans spanning multiple * Objects. * * @param bean the Bean to cast. * @param newClass the Class to cast it to. * * @return the Bean as a new view, or if the operation * could not be performed, the Bean itself. */ public static Object getInstanceOf(Object bean, Class newClass) { return bean; } /** * Determine whether the Bean can be cast to a different * class type. * This should be used instead of instanceof to determine * a Bean's castability, because in the future there may * be new types of Bean, even Beans spanning multiple * Objects. * * @param bean the Bean to cast. * @param newClass the Class to cast it to. * * @return whether the Bean can be cast to the class type * in question. */ public static boolean isInstanceOf(Object bean, Class newBeanClass) { return newBeanClass.isInstance(bean); } /** * Find out whether the GUI is available to use. * Defaults to true. * * @return whether the GUI is available to use. */ public static boolean isGuiAvailable() { return guiAvailable; } /** * Find out whether it is design time. Design time means * we are in a RAD tool. * Defaults to false. * * @return whether it is design time. */ public static boolean isDesignTime() { return designTime; } /** * Set whether the GUI is available to use. * @param guiAvailable whether the GUI is available to use. */ public static void setGuiAvailable(boolean guiAvailable) throws SecurityException { Beans.guiAvailable = guiAvailable; } /** * Set whether it is design time. Design time means we * are in a RAD tool. * * @param designTime whether it is design time. */ public static void setDesignTime(boolean designTime) throws SecurityException { Beans.designTime = designTime; }}
?? 快捷鍵說明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -