src/main/java/javax/activation/CommandInfo.java - java/activation - Git at Google

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved.
  *
  * The contents of this file are subject to the terms of either the GNU
  * General Public License Version 2 only ("GPL") or the Common Development
  * and Distribution License("CDDL") (collectively, the "License").  You
  * may not use this file except in compliance with the License.  You can
  * obtain a copy of the License at
  * https://oss.oracle.com/licenses/CDDL+GPL-1.1
  * or LICENSE.txt.  See the License for the specific
  * language governing permissions and limitations under the License.
  *
  * When distributing the software, include this License Header Notice in each
  * file and include the License file at LICENSE.txt.
  *
  * GPL Classpath Exception:
  * Oracle designates this particular file as subject to the "Classpath"
  * exception as provided by Oracle in the GPL Version 2 section of the License
  * file that accompanied this code.
  *
  * Modifications:
  * If applicable, add the following below the License Header, with the fields
  * enclosed by brackets [] replaced by your own identifying information:
  * "Portions Copyright [year] [name of copyright owner]"
  *
  * Contributor(s):
  * If you wish your version of this file to be governed by only the CDDL or
  * only the GPL Version 2, indicate your decision by adding "[Contributor]
  * elects to include this software in this distribution under the [CDDL or GPL
  * Version 2] license."  If you don't indicate a single choice of license, a
  * recipient has the option to distribute your version of this file under
  * either the CDDL, the GPL Version 2 or to extend the choice of license to
  * its licensees as provided above.  However, if you add GPL Version 2 code
  * and therefore, elected the GPL Version 2 license, then the option applies
  * only if the new code is made subject to such option by the copyright
  * holder.
  */

 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.
  */

 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 the current runtime environment supports
      * {@link java.beans.Beans#instantiate Beans.instantiate},
      * use it to instantiate the JavaBeans component.  Otherwise, use
      * {@link java.lang.Class#forName Class.forName}.
      * <p>
      * The component class needs to be public.
      * On Java SE 9 and newer, if the component class is in a named module,
      * it needs to be in an exported package.
      * <p>
      * If the bean implements the <code>javax.activation.CommandObject</code>
      * interface, call its <code>setCommandContext</code> 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, true, loader);
                 try {
                     return beanClass.newInstance();
                 } catch (Exception ex) {
                     throw new ClassNotFoundException(beanClass + ": " + ex, ex);
                 }

             }
             return null;
         }
     }
 }
	/*
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
	*
	* Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved.
	*
	* The contents of this file are subject to the terms of either the GNU
	* General Public License Version 2 only ("GPL") or the Common Development
	* and Distribution License("CDDL") (collectively, the "License"). You
	* may not use this file except in compliance with the License. You can
	* obtain a copy of the License at
	* https://oss.oracle.com/licenses/CDDL+GPL-1.1
	* or LICENSE.txt. See the License for the specific
	* language governing permissions and limitations under the License.
	*
	* When distributing the software, include this License Header Notice in each
	* file and include the License file at LICENSE.txt.
	*
	* GPL Classpath Exception:
	* Oracle designates this particular file as subject to the "Classpath"
	* exception as provided by Oracle in the GPL Version 2 section of the License
	* file that accompanied this code.
	*
	* Modifications:
	* If applicable, add the following below the License Header, with the fields
	* enclosed by brackets [] replaced by your own identifying information:
	* "Portions Copyright [year] [name of copyright owner]"
	*
	* Contributor(s):
	* If you wish your version of this file to be governed by only the CDDL or
	* only the GPL Version 2, indicate your decision by adding "[Contributor]
	* elects to include this software in this distribution under the [CDDL or GPL
	* Version 2] license." If you don't indicate a single choice of license, a
	* recipient has the option to distribute your version of this file under
	* either the CDDL, the GPL Version 2 or to extend the choice of license to
	* its licensees as provided above. However, if you add GPL Version 2 code
	* and therefore, elected the GPL Version 2 license, then the option applies
	* only if the new code is made subject to such option by the copyright
	* holder.
	*/

	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.
	*/

	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 the current runtime environment supports
	* {@link java.beans.Beans#instantiate Beans.instantiate},
	* use it to instantiate the JavaBeans component. Otherwise, use
	* {@link java.lang.Class#forName Class.forName}.
	* <p>
	* The component class needs to be public.
	* On Java SE 9 and newer, if the component class is in a named module,
	* it needs to be in an exported package.
	* <p>
	* If the bean implements the <code>javax.activation.CommandObject</code>
	* interface, call its <code>setCommandContext</code> 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, true, loader);
	try {
	return beanClass.newInstance();
	} catch (Exception ex) {
	throw new ClassNotFoundException(beanClass + ": " + ex, ex);
	}

	}
	return null;
	}
	}
	}