1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/jaf_classes/javax/activation/DataHandler.java Wed Apr 27 01:27:09 2016 +0800
1.3 @@ -0,0 +1,899 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package javax.activation;
1.30 +
1.31 +import java.io.InputStream;
1.32 +import java.io.IOException;
1.33 +import java.io.OutputStream;
1.34 +import java.io.PipedInputStream;
1.35 +import java.io.PipedOutputStream;
1.36 +import java.io.OutputStreamWriter;
1.37 +import java.net.URL;
1.38 +import java.awt.datatransfer.Transferable;
1.39 +import java.awt.datatransfer.DataFlavor;
1.40 +import java.awt.datatransfer.UnsupportedFlavorException;
1.41 +
1.42 +/**
1.43 + * The DataHandler class provides a consistent interface to data
1.44 + * available in many different sources and formats.
1.45 + * It manages simple stream to string conversions and related operations
1.46 + * using DataContentHandlers.
1.47 + * It provides access to commands that can operate on the data.
1.48 + * The commands are found using a CommandMap. <p>
1.49 + *
1.50 + * <b>DataHandler and the Transferable Interface</b><p>
1.51 + * DataHandler implements the Transferable interface so that data can
1.52 + * be used in AWT data transfer operations, such as cut and paste and
1.53 + * drag and drop. The implementation of the Transferable interface
1.54 + * relies on the availability of an installed DataContentHandler
1.55 + * object corresponding to the MIME type of the data represented in
1.56 + * the specific instance of the DataHandler.<p>
1.57 + *
1.58 + * <b>DataHandler and CommandMaps</b><p>
1.59 + * The DataHandler keeps track of the current CommandMap that it uses to
1.60 + * service requests for commands (<code>getCommand</code>,
1.61 + * <code>getAllCommands</code>, <code>getPreferredCommands</code>).
1.62 + * Each instance of a DataHandler may have a CommandMap associated with
1.63 + * it using the <code>setCommandMap</code> method. If a CommandMap was
1.64 + * not set, DataHandler calls the <code>getDefaultCommandMap</code>
1.65 + * method in CommandMap and uses the value it returns. See
1.66 + * <i>CommandMap</i> for more information. <p>
1.67 + *
1.68 + * <b>DataHandler and URLs</b><p>
1.69 + * The current DataHandler implementation creates a private
1.70 + * instance of URLDataSource when it is constructed with a URL.
1.71 + *
1.72 + * @see javax.activation.CommandMap
1.73 + * @see javax.activation.DataContentHandler
1.74 + * @see javax.activation.DataSource
1.75 + * @see javax.activation.URLDataSource
1.76 + *
1.77 + * @since 1.6
1.78 + */
1.79 +
1.80 +public class DataHandler implements Transferable {
1.81 +
1.82 + // Use the datasource to indicate whether we were started via the
1.83 + // DataSource constructor or the object constructor.
1.84 + private DataSource dataSource = null;
1.85 + private DataSource objDataSource = null;
1.86 +
1.87 + // The Object and mimetype from the constructor (if passed in).
1.88 + // object remains null if it was instantiated with a
1.89 + // DataSource.
1.90 + private Object object = null;
1.91 + private String objectMimeType = null;
1.92 +
1.93 + // Keep track of the CommandMap
1.94 + private CommandMap currentCommandMap = null;
1.95 +
1.96 + // our transfer flavors
1.97 + private static final DataFlavor emptyFlavors[] = new DataFlavor[0];
1.98 + private DataFlavor transferFlavors[] = emptyFlavors;
1.99 +
1.100 + // our DataContentHandler
1.101 + private DataContentHandler dataContentHandler = null;
1.102 + private DataContentHandler factoryDCH = null;
1.103 +
1.104 + // our DataContentHandlerFactory
1.105 + private static DataContentHandlerFactory factory = null;
1.106 + private DataContentHandlerFactory oldFactory = null;
1.107 + // the short representation of the ContentType (sans params)
1.108 + private String shortType = null;
1.109 +
1.110 + /**
1.111 + * Create a <code>DataHandler</code> instance referencing the
1.112 + * specified DataSource. The data exists in a byte stream form.
1.113 + * The DataSource will provide an InputStream to access the data.
1.114 + *
1.115 + * @param ds the DataSource
1.116 + */
1.117 + public DataHandler(DataSource ds) {
1.118 + // save a reference to the incoming DS
1.119 + dataSource = ds;
1.120 + oldFactory = factory; // keep track of the factory
1.121 + }
1.122 +
1.123 + /**
1.124 + * Create a <code>DataHandler</code> instance representing an object
1.125 + * of this MIME type. This constructor is
1.126 + * used when the application already has an in-memory representation
1.127 + * of the data in the form of a Java Object.
1.128 + *
1.129 + * @param obj the Java Object
1.130 + * @param mimeType the MIME type of the object
1.131 + */
1.132 + public DataHandler(Object obj, String mimeType) {
1.133 + object = obj;
1.134 + objectMimeType = mimeType;
1.135 + oldFactory = factory; // keep track of the factory
1.136 + }
1.137 +
1.138 + /**
1.139 + * Create a <code>DataHandler</code> instance referencing a URL.
1.140 + * The DataHandler internally creates a <code>URLDataSource</code>
1.141 + * instance to represent the URL.
1.142 + *
1.143 + * @param url a URL object
1.144 + */
1.145 + public DataHandler(URL url) {
1.146 + dataSource = new URLDataSource(url);
1.147 + oldFactory = factory; // keep track of the factory
1.148 + }
1.149 +
1.150 + /**
1.151 + * Return the CommandMap for this instance of DataHandler.
1.152 + */
1.153 + private synchronized CommandMap getCommandMap() {
1.154 + if (currentCommandMap != null)
1.155 + return currentCommandMap;
1.156 + else
1.157 + return CommandMap.getDefaultCommandMap();
1.158 + }
1.159 +
1.160 + /**
1.161 + * Return the DataSource associated with this instance
1.162 + * of DataHandler.
1.163 + * <p>
1.164 + * For DataHandlers that have been instantiated with a DataSource,
1.165 + * this method returns the DataSource that was used to create the
1.166 + * DataHandler object. In other cases the DataHandler
1.167 + * constructs a DataSource from the data used to construct
1.168 + * the DataHandler. DataSources created for DataHandlers <b>not</b>
1.169 + * instantiated with a DataSource are cached for performance
1.170 + * reasons.
1.171 + *
1.172 + * @return a valid DataSource object for this DataHandler
1.173 + */
1.174 + public DataSource getDataSource() {
1.175 + if (dataSource == null) {
1.176 + // create one on the fly
1.177 + if (objDataSource == null)
1.178 + objDataSource = new DataHandlerDataSource(this);
1.179 + return objDataSource;
1.180 + }
1.181 + return dataSource;
1.182 + }
1.183 +
1.184 + /**
1.185 + * Return the name of the data object. If this DataHandler
1.186 + * was created with a DataSource, this method calls through
1.187 + * to the <code>DataSource.getName</code> method, otherwise it
1.188 + * returns <i>null</i>.
1.189 + *
1.190 + * @return the name of the object
1.191 + */
1.192 + public String getName() {
1.193 + if (dataSource != null)
1.194 + return dataSource.getName();
1.195 + else
1.196 + return null;
1.197 + }
1.198 +
1.199 + /**
1.200 + * Return the MIME type of this object as retrieved from
1.201 + * the source object. Note that this is the <i>full</i>
1.202 + * type with parameters.
1.203 + *
1.204 + * @return the MIME type
1.205 + */
1.206 + public String getContentType() {
1.207 + if (dataSource != null) // data source case
1.208 + return dataSource.getContentType();
1.209 + else
1.210 + return objectMimeType; // obj/type case
1.211 + }
1.212 +
1.213 + /**
1.214 + * Get the InputStream for this object. <p>
1.215 + *
1.216 + * For DataHandlers instantiated with a DataSource, the DataHandler
1.217 + * calls the <code>DataSource.getInputStream</code> method and
1.218 + * returns the result to the caller.
1.219 + * <p>
1.220 + * For DataHandlers instantiated with an Object, the DataHandler
1.221 + * first attempts to find a DataContentHandler for the Object. If
1.222 + * the DataHandler can not find a DataContentHandler for this MIME
1.223 + * type, it throws an UnsupportedDataTypeException. If it is
1.224 + * successful, it creates a pipe and a thread. The thread uses the
1.225 + * DataContentHandler's <code>writeTo</code> method to write the
1.226 + * stream data into one end of the pipe. The other end of the pipe
1.227 + * is returned to the caller. Because a thread is created to copy
1.228 + * the data, IOExceptions that may occur during the copy can not be
1.229 + * propagated back to the caller. The result is an empty stream.<p>
1.230 + *
1.231 + * @return the InputStream representing this data
1.232 + * @exception IOException if an I/O error occurs
1.233 + *
1.234 + * @see javax.activation.DataContentHandler#writeTo
1.235 + * @see javax.activation.UnsupportedDataTypeException
1.236 + */
1.237 + public InputStream getInputStream() throws IOException {
1.238 + InputStream ins = null;
1.239 +
1.240 + if (dataSource != null) {
1.241 + ins = dataSource.getInputStream();
1.242 + } else {
1.243 + DataContentHandler dch = getDataContentHandler();
1.244 + // we won't even try if we can't get a dch
1.245 + if (dch == null)
1.246 + throw new UnsupportedDataTypeException(
1.247 + "no DCH for MIME type " + getBaseType());
1.248 +
1.249 + if (dch instanceof ObjectDataContentHandler) {
1.250 + if (((ObjectDataContentHandler)dch).getDCH() == null)
1.251 + throw new UnsupportedDataTypeException(
1.252 + "no object DCH for MIME type " + getBaseType());
1.253 + }
1.254 + // there is none but the default^^^^^^^^^^^^^^^^
1.255 + final DataContentHandler fdch = dch;
1.256 +
1.257 + // from bill s.
1.258 + // ce n'est pas une pipe!
1.259 + //
1.260 + // NOTE: This block of code needs to throw exceptions, but
1.261 + // can't because it is in another thread!!! ARG!
1.262 + //
1.263 + final PipedOutputStream pos = new PipedOutputStream();
1.264 + PipedInputStream pin = new PipedInputStream(pos);
1.265 + new Thread(
1.266 + new Runnable() {
1.267 + public void run() {
1.268 + try {
1.269 + fdch.writeTo(object, objectMimeType, pos);
1.270 + } catch (IOException e) {
1.271 +
1.272 + } finally {
1.273 + try {
1.274 + pos.close();
1.275 + } catch (IOException ie) { }
1.276 + }
1.277 + }
1.278 + },
1.279 + "DataHandler.getInputStream").start();
1.280 + ins = pin;
1.281 + }
1.282 +
1.283 + return ins;
1.284 + }
1.285 +
1.286 + /**
1.287 + * Write the data to an <code>OutputStream</code>.<p>
1.288 + *
1.289 + * If the DataHandler was created with a DataSource, writeTo
1.290 + * retrieves the InputStream and copies the bytes from the
1.291 + * InputStream to the OutputStream passed in.
1.292 + * <p>
1.293 + * If the DataHandler was created with an object, writeTo
1.294 + * retrieves the DataContentHandler for the object's type.
1.295 + * If the DataContentHandler was found, it calls the
1.296 + * <code>writeTo</code> method on the <code>DataContentHandler</code>.
1.297 + *
1.298 + * @param os the OutputStream to write to
1.299 + * @exception IOException if an I/O error occurs
1.300 + */
1.301 + public void writeTo(OutputStream os) throws IOException {
1.302 + // for the DataSource case
1.303 + if (dataSource != null) {
1.304 + InputStream is = null;
1.305 + byte data[] = new byte[8*1024];
1.306 + int bytes_read;
1.307 +
1.308 + is = dataSource.getInputStream();
1.309 +
1.310 + try {
1.311 + while ((bytes_read = is.read(data)) > 0) {
1.312 + os.write(data, 0, bytes_read);
1.313 + }
1.314 + } finally {
1.315 + is.close();
1.316 + is = null;
1.317 + }
1.318 + } else { // for the Object case
1.319 + DataContentHandler dch = getDataContentHandler();
1.320 + dch.writeTo(object, objectMimeType, os);
1.321 + }
1.322 + }
1.323 +
1.324 + /**
1.325 + * Get an OutputStream for this DataHandler to allow overwriting
1.326 + * the underlying data.
1.327 + * If the DataHandler was created with a DataSource, the
1.328 + * DataSource's <code>getOutputStream</code> method is called.
1.329 + * Otherwise, <code>null</code> is returned.
1.330 + *
1.331 + * @return the OutputStream
1.332 + *
1.333 + * @see javax.activation.DataSource#getOutputStream
1.334 + * @see javax.activation.URLDataSource
1.335 + */
1.336 + public OutputStream getOutputStream() throws IOException {
1.337 + if (dataSource != null)
1.338 + return dataSource.getOutputStream();
1.339 + else
1.340 + return null;
1.341 + }
1.342 +
1.343 + /**
1.344 + * Return the DataFlavors in which this data is available. <p>
1.345 + *
1.346 + * Returns an array of DataFlavor objects indicating the flavors
1.347 + * the data can be provided in. The array is usually ordered
1.348 + * according to preference for providing the data, from most
1.349 + * richly descriptive to least richly descriptive.<p>
1.350 + *
1.351 + * The DataHandler attempts to find a DataContentHandler that
1.352 + * corresponds to the MIME type of the data. If one is located,
1.353 + * the DataHandler calls the DataContentHandler's
1.354 + * <code>getTransferDataFlavors</code> method. <p>
1.355 + *
1.356 + * If a DataContentHandler can <i>not</i> be located, and if the
1.357 + * DataHandler was created with a DataSource (or URL), one
1.358 + * DataFlavor is returned that represents this object's MIME type
1.359 + * and the <code>java.io.InputStream</code> class. If the
1.360 + * DataHandler was created with an object and a MIME type,
1.361 + * getTransferDataFlavors returns one DataFlavor that represents
1.362 + * this object's MIME type and the object's class.
1.363 + *
1.364 + * @return an array of data flavors in which this data can be transferred
1.365 + * @see javax.activation.DataContentHandler#getTransferDataFlavors
1.366 + */
1.367 + public synchronized DataFlavor[] getTransferDataFlavors() {
1.368 + if (factory != oldFactory) // if the factory has changed, clear cache
1.369 + transferFlavors = emptyFlavors;
1.370 +
1.371 + // if it's not set, set it...
1.372 + if (transferFlavors == emptyFlavors)
1.373 + transferFlavors = getDataContentHandler().getTransferDataFlavors();
1.374 +
1.375 + if (transferFlavors == emptyFlavors)
1.376 + return transferFlavors;
1.377 + else
1.378 + return transferFlavors.clone();
1.379 +
1.380 + }
1.381 +
1.382 + /**
1.383 + * Returns whether the specified data flavor is supported
1.384 + * for this object.<p>
1.385 + *
1.386 + * This method iterates through the DataFlavors returned from
1.387 + * <code>getTransferDataFlavors</code>, comparing each with
1.388 + * the specified flavor.
1.389 + *
1.390 + * @param flavor the requested flavor for the data
1.391 + * @return true if the data flavor is supported
1.392 + * @see javax.activation.DataHandler#getTransferDataFlavors
1.393 + */
1.394 + public boolean isDataFlavorSupported(DataFlavor flavor) {
1.395 + DataFlavor[] lFlavors = getTransferDataFlavors();
1.396 +
1.397 + for (int i = 0; i < lFlavors.length; i++) {
1.398 + if (lFlavors[i].equals(flavor))
1.399 + return true;
1.400 + }
1.401 + return false;
1.402 + }
1.403 +
1.404 + /**
1.405 + * Returns an object that represents the data to be
1.406 + * transferred. The class of the object returned is defined by the
1.407 + * representation class of the data flavor.<p>
1.408 + *
1.409 + * <b>For DataHandler's created with DataSources or URLs:</b><p>
1.410 + *
1.411 + * The DataHandler attempts to locate a DataContentHandler
1.412 + * for this MIME type. If one is found, the passed in DataFlavor
1.413 + * and the type of the data are passed to its <code>getTransferData</code>
1.414 + * method. If the DataHandler fails to locate a DataContentHandler
1.415 + * and the flavor specifies this object's MIME type and the
1.416 + * <code>java.io.InputStream</code> class, this object's InputStream
1.417 + * is returned.
1.418 + * Otherwise it throws an UnsupportedFlavorException. <p>
1.419 + *
1.420 + * <b>For DataHandler's created with Objects:</b><p>
1.421 + *
1.422 + * The DataHandler attempts to locate a DataContentHandler
1.423 + * for this MIME type. If one is found, the passed in DataFlavor
1.424 + * and the type of the data are passed to its getTransferData
1.425 + * method. If the DataHandler fails to locate a DataContentHandler
1.426 + * and the flavor specifies this object's MIME type and its class,
1.427 + * this DataHandler's referenced object is returned.
1.428 + * Otherwise it throws an UnsupportedFlavorException.
1.429 + *
1.430 + * @param flavor the requested flavor for the data
1.431 + * @return the object
1.432 + * @exception UnsupportedFlavorException if the data could not be
1.433 + * converted to the requested flavor
1.434 + * @exception IOException if an I/O error occurs
1.435 + * @see javax.activation.ActivationDataFlavor
1.436 + */
1.437 + public Object getTransferData(DataFlavor flavor)
1.438 + throws UnsupportedFlavorException, IOException {
1.439 + return getDataContentHandler().getTransferData(flavor, dataSource);
1.440 + }
1.441 +
1.442 + /**
1.443 + * Set the CommandMap for use by this DataHandler.
1.444 + * Setting it to <code>null</code> causes the CommandMap to revert
1.445 + * to the CommandMap returned by the
1.446 + * <code>CommandMap.getDefaultCommandMap</code> method.
1.447 + * Changing the CommandMap, or setting it to <code>null</code>,
1.448 + * clears out any data cached from the previous CommandMap.
1.449 + *
1.450 + * @param commandMap the CommandMap to use in this DataHandler
1.451 + *
1.452 + * @see javax.activation.CommandMap#setDefaultCommandMap
1.453 + */
1.454 + public synchronized void setCommandMap(CommandMap commandMap) {
1.455 + if (commandMap != currentCommandMap || commandMap == null) {
1.456 + // clear cached values...
1.457 + transferFlavors = emptyFlavors;
1.458 + dataContentHandler = null;
1.459 +
1.460 + currentCommandMap = commandMap;
1.461 + }
1.462 + }
1.463 +
1.464 + /**
1.465 + * Return the <i>preferred</i> commands for this type of data.
1.466 + * This method calls the <code>getPreferredCommands</code> method
1.467 + * in the CommandMap associated with this instance of DataHandler.
1.468 + * This method returns an array that represents a subset of
1.469 + * available commands. In cases where multiple commands for the
1.470 + * MIME type represented by this DataHandler are present, the
1.471 + * installed CommandMap chooses the appropriate commands.
1.472 + *
1.473 + * @return the CommandInfo objects representing the preferred commands
1.474 + *
1.475 + * @see javax.activation.CommandMap#getPreferredCommands
1.476 + */
1.477 + public CommandInfo[] getPreferredCommands() {
1.478 + if (dataSource != null)
1.479 + return getCommandMap().getPreferredCommands(getBaseType(),
1.480 + dataSource);
1.481 + else
1.482 + return getCommandMap().getPreferredCommands(getBaseType());
1.483 + }
1.484 +
1.485 + /**
1.486 + * Return all the commands for this type of data.
1.487 + * This method returns an array containing all commands
1.488 + * for the type of data represented by this DataHandler. The
1.489 + * MIME type for the underlying data represented by this DataHandler
1.490 + * is used to call through to the <code>getAllCommands</code> method
1.491 + * of the CommandMap associated with this DataHandler.
1.492 + *
1.493 + * @return the CommandInfo objects representing all the commands
1.494 + *
1.495 + * @see javax.activation.CommandMap#getAllCommands
1.496 + */
1.497 + public CommandInfo[] getAllCommands() {
1.498 + if (dataSource != null)
1.499 + return getCommandMap().getAllCommands(getBaseType(), dataSource);
1.500 + else
1.501 + return getCommandMap().getAllCommands(getBaseType());
1.502 + }
1.503 +
1.504 + /**
1.505 + * Get the command <i>cmdName</i>. Use the search semantics as
1.506 + * defined by the CommandMap installed in this DataHandler. The
1.507 + * MIME type for the underlying data represented by this DataHandler
1.508 + * is used to call through to the <code>getCommand</code> method
1.509 + * of the CommandMap associated with this DataHandler.
1.510 + *
1.511 + * @param cmdName the command name
1.512 + * @return the CommandInfo corresponding to the command
1.513 + *
1.514 + * @see javax.activation.CommandMap#getCommand
1.515 + */
1.516 + public CommandInfo getCommand(String cmdName) {
1.517 + if (dataSource != null)
1.518 + return getCommandMap().getCommand(getBaseType(), cmdName,
1.519 + dataSource);
1.520 + else
1.521 + return getCommandMap().getCommand(getBaseType(), cmdName);
1.522 + }
1.523 +
1.524 + /**
1.525 + * Return the data in its preferred Object form. <p>
1.526 + *
1.527 + * If the DataHandler was instantiated with an object, return
1.528 + * the object. <p>
1.529 + *
1.530 + * If the DataHandler was instantiated with a DataSource,
1.531 + * this method uses a DataContentHandler to return the content
1.532 + * object for the data represented by this DataHandler. If no
1.533 + * <code>DataContentHandler</code> can be found for the
1.534 + * the type of this data, the DataHandler returns an
1.535 + * InputStream for the data.
1.536 + *
1.537 + * @return the content.
1.538 + * @exception IOException if an IOException occurs during
1.539 + * this operation.
1.540 + */
1.541 + public Object getContent() throws IOException {
1.542 + if (object != null)
1.543 + return object;
1.544 + else
1.545 + return getDataContentHandler().getContent(getDataSource());
1.546 + }
1.547 +
1.548 + /**
1.549 + * A convenience method that takes a CommandInfo object
1.550 + * and instantiates the corresponding command, usually
1.551 + * a JavaBean component.
1.552 + * <p>
1.553 + * This method calls the CommandInfo's <code>getCommandObject</code>
1.554 + * method with the <code>ClassLoader</code> used to load
1.555 + * the <code>javax.activation.DataHandler</code> class itself.
1.556 + *
1.557 + * @param cmdinfo the CommandInfo corresponding to a command
1.558 + * @return the instantiated command object
1.559 + */
1.560 + public Object getBean(CommandInfo cmdinfo) {
1.561 + Object bean = null;
1.562 +
1.563 + try {
1.564 + // make the bean
1.565 + ClassLoader cld = null;
1.566 + // First try the "application's" class loader.
1.567 + cld = SecuritySupport.getContextClassLoader();
1.568 + if (cld == null)
1.569 + cld = this.getClass().getClassLoader();
1.570 + bean = cmdinfo.getCommandObject(this, cld);
1.571 + } catch (IOException e) {
1.572 + } catch (ClassNotFoundException e) { }
1.573 +
1.574 + return bean;
1.575 + }
1.576 +
1.577 + /**
1.578 + * Get the DataContentHandler for this DataHandler: <p>
1.579 + *
1.580 + * If a DataContentHandlerFactory is set, use it.
1.581 + * Otherwise look for an object to serve DCH in the
1.582 + * following order: <p>
1.583 + *
1.584 + * 1) if a factory is set, use it <p>
1.585 + * 2) if a CommandMap is set, use it <p>
1.586 + * 3) use the default CommandMap <p>
1.587 + *
1.588 + * In any case, wrap the real DataContentHandler with one of our own
1.589 + * to handle any missing cases, fill in defaults, and to ensure that
1.590 + * we always have a non-null DataContentHandler.
1.591 + *
1.592 + * @return the requested DataContentHandler
1.593 + */
1.594 + private synchronized DataContentHandler getDataContentHandler() {
1.595 +
1.596 + // make sure the factory didn't change
1.597 + if (factory != oldFactory) {
1.598 + oldFactory = factory;
1.599 + factoryDCH = null;
1.600 + dataContentHandler = null;
1.601 + transferFlavors = emptyFlavors;
1.602 + }
1.603 +
1.604 + if (dataContentHandler != null)
1.605 + return dataContentHandler;
1.606 +
1.607 + String simpleMT = getBaseType();
1.608 +
1.609 + if (factoryDCH == null && factory != null)
1.610 + factoryDCH = factory.createDataContentHandler(simpleMT);
1.611 +
1.612 + if (factoryDCH != null)
1.613 + dataContentHandler = factoryDCH;
1.614 +
1.615 + if (dataContentHandler == null) {
1.616 + if (dataSource != null)
1.617 + dataContentHandler = getCommandMap().
1.618 + createDataContentHandler(simpleMT, dataSource);
1.619 + else
1.620 + dataContentHandler = getCommandMap().
1.621 + createDataContentHandler(simpleMT);
1.622 + }
1.623 +
1.624 + // getDataContentHandler always uses these 'wrapper' handlers
1.625 + // to make sure it returns SOMETHING meaningful...
1.626 + if (dataSource != null)
1.627 + dataContentHandler = new DataSourceDataContentHandler(
1.628 + dataContentHandler,
1.629 + dataSource);
1.630 + else
1.631 + dataContentHandler = new ObjectDataContentHandler(
1.632 + dataContentHandler,
1.633 + object,
1.634 + objectMimeType);
1.635 + return dataContentHandler;
1.636 + }
1.637 +
1.638 + /**
1.639 + * Use the MimeType class to extract the MIME type/subtype,
1.640 + * ignoring the parameters. The type is cached.
1.641 + */
1.642 + private synchronized String getBaseType() {
1.643 + if (shortType == null) {
1.644 + String ct = getContentType();
1.645 + try {
1.646 + MimeType mt = new MimeType(ct);
1.647 + shortType = mt.getBaseType();
1.648 + } catch (MimeTypeParseException e) {
1.649 + shortType = ct;
1.650 + }
1.651 + }
1.652 + return shortType;
1.653 + }
1.654 +
1.655 + /**
1.656 + * Sets the DataContentHandlerFactory. The DataContentHandlerFactory
1.657 + * is called first to find DataContentHandlers.
1.658 + * The DataContentHandlerFactory can only be set once.
1.659 + * <p>
1.660 + * If the DataContentHandlerFactory has already been set,
1.661 + * this method throws an Error.
1.662 + *
1.663 + * @param newFactory the DataContentHandlerFactory
1.664 + * @exception Error if the factory has already been defined.
1.665 + *
1.666 + * @see javax.activation.DataContentHandlerFactory
1.667 + */
1.668 + public static synchronized void setDataContentHandlerFactory(
1.669 + DataContentHandlerFactory newFactory) {
1.670 + if (factory != null)
1.671 + throw new Error("DataContentHandlerFactory already defined");
1.672 +
1.673 + SecurityManager security = System.getSecurityManager();
1.674 + if (security != null) {
1.675 + try {
1.676 + // if it's ok with the SecurityManager, it's ok with me...
1.677 + security.checkSetFactory();
1.678 + } catch (SecurityException ex) {
1.679 + // otherwise, we also allow it if this code and the
1.680 + // factory come from the same class loader (e.g.,
1.681 + // the JAF classes were loaded with the applet classes).
1.682 + if (DataHandler.class.getClassLoader() !=
1.683 + newFactory.getClass().getClassLoader())
1.684 + throw ex;
1.685 + }
1.686 + }
1.687 + factory = newFactory;
1.688 + }
1.689 +}
1.690 +
1.691 +/**
1.692 + * The DataHanderDataSource class implements the
1.693 + * DataSource interface when the DataHandler is constructed
1.694 + * with an Object and a mimeType string.
1.695 + */
1.696 +class DataHandlerDataSource implements DataSource {
1.697 + DataHandler dataHandler = null;
1.698 +
1.699 + /**
1.700 + * The constructor.
1.701 + */
1.702 + public DataHandlerDataSource(DataHandler dh) {
1.703 + this.dataHandler = dh;
1.704 + }
1.705 +
1.706 + /**
1.707 + * Returns an <code>InputStream</code> representing this object.
1.708 + * @return the <code>InputStream</code>
1.709 + */
1.710 + public InputStream getInputStream() throws IOException {
1.711 + return dataHandler.getInputStream();
1.712 + }
1.713 +
1.714 + /**
1.715 + * Returns the <code>OutputStream</code> for this object.
1.716 + * @return the <code>OutputStream</code>
1.717 + */
1.718 + public OutputStream getOutputStream() throws IOException {
1.719 + return dataHandler.getOutputStream();
1.720 + }
1.721 +
1.722 + /**
1.723 + * Returns the MIME type of the data represented by this object.
1.724 + * @return the MIME type
1.725 + */
1.726 + public String getContentType() {
1.727 + return dataHandler.getContentType();
1.728 + }
1.729 +
1.730 + /**
1.731 + * Returns the name of this object.
1.732 + * @return the name of this object
1.733 + */
1.734 + public String getName() {
1.735 + return dataHandler.getName(); // what else would it be?
1.736 + }
1.737 +}
1.738 +
1.739 +/*
1.740 + * DataSourceDataContentHandler
1.741 + *
1.742 + * This is a <i>private</i> DataContentHandler that wraps the real
1.743 + * DataContentHandler in the case where the DataHandler was instantiated
1.744 + * with a DataSource.
1.745 + */
1.746 +class DataSourceDataContentHandler implements DataContentHandler {
1.747 + private DataSource ds = null;
1.748 + private DataFlavor transferFlavors[] = null;
1.749 + private DataContentHandler dch = null;
1.750 +
1.751 + /**
1.752 + * The constructor.
1.753 + */
1.754 + public DataSourceDataContentHandler(DataContentHandler dch, DataSource ds) {
1.755 + this.ds = ds;
1.756 + this.dch = dch;
1.757 + }
1.758 +
1.759 + /**
1.760 + * Return the DataFlavors for this <code>DataContentHandler</code>.
1.761 + * @return the DataFlavors
1.762 + */
1.763 + public DataFlavor[] getTransferDataFlavors() {
1.764 +
1.765 + if (transferFlavors == null) {
1.766 + if (dch != null) { // is there a dch?
1.767 + transferFlavors = dch.getTransferDataFlavors();
1.768 + } else {
1.769 + transferFlavors = new DataFlavor[1];
1.770 + transferFlavors[0] =
1.771 + new ActivationDataFlavor(ds.getContentType(),
1.772 + ds.getContentType());
1.773 + }
1.774 + }
1.775 + return transferFlavors;
1.776 + }
1.777 +
1.778 + /**
1.779 + * Return the Transfer Data of type DataFlavor from InputStream.
1.780 + * @param df the DataFlavor
1.781 + * @param ds the DataSource
1.782 + * @return the constructed Object
1.783 + */
1.784 + public Object getTransferData(DataFlavor df, DataSource ds) throws
1.785 + UnsupportedFlavorException, IOException {
1.786 +
1.787 + if (dch != null)
1.788 + return dch.getTransferData(df, ds);
1.789 + else if (df.equals(getTransferDataFlavors()[0])) // only have one now
1.790 + return ds.getInputStream();
1.791 + else
1.792 + throw new UnsupportedFlavorException(df);
1.793 + }
1.794 +
1.795 + public Object getContent(DataSource ds) throws IOException {
1.796 +
1.797 + if (dch != null)
1.798 + return dch.getContent(ds);
1.799 + else
1.800 + return ds.getInputStream();
1.801 + }
1.802 +
1.803 + /**
1.804 + * Write the object to the output stream.
1.805 + */
1.806 + public void writeTo(Object obj, String mimeType, OutputStream os)
1.807 + throws IOException {
1.808 + if (dch != null)
1.809 + dch.writeTo(obj, mimeType, os);
1.810 + else
1.811 + throw new UnsupportedDataTypeException(
1.812 + "no DCH for content type " + ds.getContentType());
1.813 + }
1.814 +}
1.815 +
1.816 +/*
1.817 + * ObjectDataContentHandler
1.818 + *
1.819 + * This is a <i>private</i> DataContentHandler that wraps the real
1.820 + * DataContentHandler in the case where the DataHandler was instantiated
1.821 + * with an object.
1.822 + */
1.823 +class ObjectDataContentHandler implements DataContentHandler {
1.824 + private DataFlavor transferFlavors[] = null;
1.825 + private Object obj;
1.826 + private String mimeType;
1.827 + private DataContentHandler dch = null;
1.828 +
1.829 + /**
1.830 + * The constructor.
1.831 + */
1.832 + public ObjectDataContentHandler(DataContentHandler dch,
1.833 + Object obj, String mimeType) {
1.834 + this.obj = obj;
1.835 + this.mimeType = mimeType;
1.836 + this.dch = dch;
1.837 + }
1.838 +
1.839 + /**
1.840 + * Return the DataContentHandler for this object.
1.841 + * Used only by the DataHandler class.
1.842 + */
1.843 + public DataContentHandler getDCH() {
1.844 + return dch;
1.845 + }
1.846 +
1.847 + /**
1.848 + * Return the DataFlavors for this <code>DataContentHandler</code>.
1.849 + * @return the DataFlavors
1.850 + */
1.851 + public synchronized DataFlavor[] getTransferDataFlavors() {
1.852 + if (transferFlavors == null) {
1.853 + if (dch != null) {
1.854 + transferFlavors = dch.getTransferDataFlavors();
1.855 + } else {
1.856 + transferFlavors = new DataFlavor[1];
1.857 + transferFlavors[0] = new ActivationDataFlavor(obj.getClass(),
1.858 + mimeType, mimeType);
1.859 + }
1.860 + }
1.861 + return transferFlavors;
1.862 + }
1.863 +
1.864 + /**
1.865 + * Return the Transfer Data of type DataFlavor from InputStream.
1.866 + * @param df the DataFlavor
1.867 + * @param ds the DataSource
1.868 + * @return the constructed Object
1.869 + */
1.870 + public Object getTransferData(DataFlavor df, DataSource ds)
1.871 + throws UnsupportedFlavorException, IOException {
1.872 +
1.873 + if (dch != null)
1.874 + return dch.getTransferData(df, ds);
1.875 + else if (df.equals(getTransferDataFlavors()[0])) // only have one now
1.876 + return obj;
1.877 + else
1.878 + throw new UnsupportedFlavorException(df);
1.879 +
1.880 + }
1.881 +
1.882 + public Object getContent(DataSource ds) {
1.883 + return obj;
1.884 + }
1.885 +
1.886 + /**
1.887 + * Write the object to the output stream.
1.888 + */
1.889 + public void writeTo(Object obj, String mimeType, OutputStream os)
1.890 + throws IOException {
1.891 + if (dch != null)
1.892 + dch.writeTo(obj, mimeType, os);
1.893 + else if (obj instanceof byte[])
1.894 + os.write((byte[])obj);
1.895 + else if (obj instanceof String) {
1.896 + OutputStreamWriter osw = new OutputStreamWriter(os);
1.897 + osw.write((String)obj);
1.898 + osw.flush();
1.899 + } else throw new UnsupportedDataTypeException(
1.900 + "no object DCH for MIME type " + this.mimeType);
1.901 + }
1.902 +}
