| /* |
| * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.activation; |
| |
| import java.io.*; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** |
| * The CommandInfo class is used by CommandMap implementations to |
| * describe the results of command requests. It provides the requestor |
| * with both the verb requested, as well as an instance of the |
| * bean. There is also a method that will return the name of the |
| * class that implements the command but <i>it is not guaranteed to |
| * return a valid value</i>. The reason for this is to allow CommandMap |
| * implmentations that subclass CommandInfo to provide special |
| * behavior. For example a CommandMap could dynamically generate |
| * JavaBeans. In this case, it might not be possible to create an |
| * object with all the correct state information solely from the class |
| * name. |
| * |
| * @since 1.6 |
| */ |
| |
| public class CommandInfo { |
| private String verb; |
| private String className; |
| |
| /** |
| * The Constructor for CommandInfo. |
| * @param verb The command verb this CommandInfo decribes. |
| * @param className The command's fully qualified class name. |
| */ |
| public CommandInfo(String verb, String className) { |
| this.verb = verb; |
| this.className = className; |
| } |
| |
| /** |
| * Return the command verb. |
| * |
| * @return the command verb. |
| */ |
| public String getCommandName() { |
| return verb; |
| } |
| |
| /** |
| * Return the command's class name. <i>This method MAY return null in |
| * cases where a CommandMap subclassed CommandInfo for its |
| * own purposes.</i> In other words, it might not be possible to |
| * create the correct state in the command by merely knowing |
| * its class name. <b>DO NOT DEPEND ON THIS METHOD RETURNING |
| * A VALID VALUE!</b> |
| * |
| * @return The class name of the command, or <i>null</i> |
| */ |
| public String getCommandClass() { |
| return className; |
| } |
| |
| /** |
| * Return the instantiated JavaBean component. |
| * <p> |
| * If {@code java.beans.Beans} is visible then it's |
| * {@code java.beans.Beans#instantiate} method is invoked to instantiate |
| * the component as a JavaBeans component. |
| * When {@code java.beans.Beans} is not visible (when {@code java.desktop} |
| * module is not readable or when the runtime image does not contain the |
| * {@code java.desktop} module) then the command's class is loaded and |
| * instantiated with its public no-args constructor. |
| * <p> |
| * The component class needs to be public. |
| * <p> |
| * If the bean implements the {@code javax.activation.CommandObject} |
| * interface, call its {@code setCommandContext} method. |
| * <p> |
| * If the DataHandler parameter is null, then the bean is |
| * instantiated with no data. NOTE: this may be useful |
| * if for some reason the DataHandler that is passed in |
| * throws IOExceptions when this method attempts to |
| * access its InputStream. It will allow the caller to |
| * retrieve a reference to the bean if it can be |
| * instantiated. |
| * <p> |
| * If the bean does NOT implement the CommandObject interface, |
| * this method will check if it implements the |
| * java.io.Externalizable interface. If it does, the bean's |
| * readExternal method will be called if an InputStream |
| * can be acquired from the DataHandler.<p> |
| * |
| * @param dh The DataHandler that describes the data to be |
| * passed to the command. |
| * @param loader The ClassLoader to be used to instantiate the bean. |
| * @return The bean |
| * @exception IOException for failures reading data |
| * @exception ClassNotFoundException if command object class can't |
| * be found |
| * @see java.beans.Beans#instantiate |
| * @see javax.activation.CommandObject |
| */ |
| public Object getCommandObject(DataHandler dh, ClassLoader loader) |
| throws IOException, ClassNotFoundException { |
| Object new_bean = null; |
| |
| // try to instantiate the bean |
| new_bean = Beans.instantiate(loader, className); |
| |
| // if we got one and it is a CommandObject |
| if (new_bean != null) { |
| if (new_bean instanceof CommandObject) { |
| ((CommandObject)new_bean).setCommandContext(verb, dh); |
| } else if (new_bean instanceof Externalizable) { |
| if (dh != null) { |
| InputStream is = dh.getInputStream(); |
| if (is != null) { |
| ((Externalizable)new_bean).readExternal( |
| new ObjectInputStream(is)); |
| } |
| } |
| } |
| } |
| |
| return new_bean; |
| } |
| |
| /** |
| * Helper class to invoke Beans.instantiate reflectively or the equivalent |
| * with core reflection when module java.desktop is not readable. |
| */ |
| private static final class Beans { |
| static final Method instantiateMethod; |
| |
| static { |
| Method m; |
| try { |
| Class<?> c = Class.forName("java.beans.Beans"); |
| m = c.getDeclaredMethod("instantiate", ClassLoader.class, String.class); |
| } catch (ClassNotFoundException e) { |
| m = null; |
| } catch (NoSuchMethodException e) { |
| m = null; |
| } |
| instantiateMethod = m; |
| } |
| |
| /** |
| * Equivalent to invoking java.beans.Beans.instantiate(loader, cn) |
| */ |
| static Object instantiate(ClassLoader loader, String cn) |
| throws IOException, ClassNotFoundException { |
| |
| Exception exception; |
| |
| if (instantiateMethod != null) { |
| |
| // invoke Beans.instantiate |
| try { |
| return instantiateMethod.invoke(null, loader, cn); |
| } catch (InvocationTargetException e) { |
| exception = e; |
| } catch (IllegalAccessException e) { |
| exception = e; |
| } |
| |
| } else { |
| |
| SecurityManager security = System.getSecurityManager(); |
| if (security != null) { |
| // if it's ok with the SecurityManager, it's ok with me. |
| String cname = cn.replace('/', '.'); |
| if (cname.startsWith("[")) { |
| int b = cname.lastIndexOf('[') + 2; |
| if (b > 1 && b < cname.length()) { |
| cname = cname.substring(b); |
| } |
| } |
| int i = cname.lastIndexOf('.'); |
| if (i != -1) { |
| security.checkPackageAccess(cname.substring(0, i)); |
| } |
| } |
| |
| // Beans.instantiate specified to use SCL when loader is null |
| if (loader == null) { |
| loader = (ClassLoader) |
| AccessController.doPrivileged(new PrivilegedAction() { |
| public Object run() { |
| ClassLoader cl = null; |
| try { |
| cl = ClassLoader.getSystemClassLoader(); |
| } catch (SecurityException ex) { } |
| return cl; |
| } |
| }); |
| } |
| Class<?> beanClass = Class.forName(cn, false, loader); |
| try { |
| return beanClass.getDeclaredConstructor().newInstance(); |
| } catch (Exception ex) { |
| throw new ClassNotFoundException(beanClass + ": " + ex, ex); |
| } |
| |
| } |
| return null; |
| } |
| } |
| } |
