com.vaadin.ui.Upload Maven / Gradle / Ivy
/*
* Vaadin Framework 7
*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.ui;
import java.io.OutputStream;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import com.vaadin.server.NoInputStreamException;
import com.vaadin.server.NoOutputStreamException;
import com.vaadin.server.PaintException;
import com.vaadin.server.PaintTarget;
import com.vaadin.server.StreamVariable.StreamingProgressEvent;
import com.vaadin.shared.EventId;
import com.vaadin.shared.ui.upload.UploadClientRpc;
import com.vaadin.shared.ui.upload.UploadServerRpc;
import com.vaadin.shared.ui.upload.UploadState;
import com.vaadin.util.ReflectTools;
/**
* Component for uploading files from client to server.
*
*
* The visible component consists of a file name input box and a browse button
* and an upload submit button to start uploading.
*
*
* The Upload component needs a java.io.OutputStream to write the uploaded data.
* You need to implement the Upload.Receiver interface and return the output
* stream in the receiveUpload() method.
*
*
* You can get an event regarding starting (StartedEvent), progress
* (ProgressEvent), and finishing (FinishedEvent) of upload by implementing
* StartedListener, ProgressListener, and FinishedListener, respectively. The
* FinishedListener is called for both failed and succeeded uploads. If you wish
* to separate between these two cases, you can use SucceededListener
* (SucceededEvenet) and FailedListener (FailedEvent).
*
*
* The upload component does not itself show upload progress, but you can use
* the ProgressIndicator for providing progress feedback by implementing
* ProgressListener and updating the indicator in updateProgress().
*
*
* Setting upload component immediate initiates the upload as soon as a file is
* selected, instead of the common pattern of file selection field and upload
* button.
*
*
* Note! Because of browser dependent implementations of
* element, setting size for Upload component is not supported. For some
* browsers setting size may work to some extend.
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class Upload extends AbstractComponent
implements Component.Focusable, LegacyComponent {
/**
* Should the field be focused on next repaint?
*/
private final boolean focus = false;
/**
* The tab order number of this field.
*/
private int tabIndex = 0;
/**
* The output of the upload is redirected to this receiver.
*/
private Receiver receiver;
private boolean isUploading;
private long contentLength = -1;
private int totalBytes;
private String buttonCaption = "Upload";
/**
* ProgressListeners to which information about progress is sent during
* upload
*/
private LinkedHashSet progressListeners;
private boolean interrupted = false;
private boolean notStarted;
private int nextid;
/**
* Creates a new instance of Upload.
*
* The receiver must be set before performing an upload.
*/
public Upload() {
registerRpc(new UploadServerRpc() {
@Override
public void change(String filename) {
fireEvent(new ChangeEvent(Upload.this, filename));
}
@Override
public void poll() {
// Nothing to do, called only to visit the server
}
});
}
public Upload(String caption, Receiver uploadReceiver) {
this();
setCaption(caption);
receiver = uploadReceiver;
}
/**
* Invoked when the value of a variable has changed.
*
* @see com.vaadin.ui.AbstractComponent#changeVariables(java.lang.Object,
* java.util.Map)
*/
@Override
public void changeVariables(Object source, Map variables) {
if (variables.containsKey("pollForStart")) {
int id = (Integer) variables.get("pollForStart");
if (!isUploading && id == nextid) {
notStarted = true;
markAsDirty();
} else {
}
}
}
/**
* Paints the content of this component.
*
* @param target
* Target to paint the content on.
* @throws PaintException
* if the paint operation failed.
*/
@Override
public void paintContent(PaintTarget target) throws PaintException {
if (notStarted) {
target.addAttribute("notStarted", true);
notStarted = false;
return;
}
// The field should be focused
if (focus) {
target.addAttribute("focus", true);
}
// The tab ordering number
if (tabIndex >= 0) {
target.addAttribute("tabindex", tabIndex);
}
target.addAttribute("state", isUploading);
if (buttonCaption != null) {
target.addAttribute("buttoncaption", buttonCaption);
}
target.addAttribute("nextid", nextid);
// Post file to this strean variable
target.addVariable(this, "action", getStreamVariable());
}
/**
* Interface that must be implemented by the upload receivers to provide the
* Upload component an output stream to write the uploaded data.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public interface Receiver extends Serializable {
/**
* Invoked when a new upload arrives.
*
* @param filename
* the desired filename of the upload, usually as specified
* by the client.
* @param mimeType
* the MIME type of the uploaded file.
* @return Stream to which the uploaded file should be written.
*/
public OutputStream receiveUpload(String filename, String mimeType);
}
/* Upload events */
private static final Method UPLOAD_FINISHED_METHOD;
private static final Method UPLOAD_FAILED_METHOD;
private static final Method UPLOAD_SUCCEEDED_METHOD;
private static final Method UPLOAD_STARTED_METHOD;
static {
try {
UPLOAD_FINISHED_METHOD = FinishedListener.class.getDeclaredMethod(
"uploadFinished", new Class[] { FinishedEvent.class });
UPLOAD_FAILED_METHOD = FailedListener.class.getDeclaredMethod(
"uploadFailed", new Class[] { FailedEvent.class });
UPLOAD_STARTED_METHOD = StartedListener.class.getDeclaredMethod(
"uploadStarted", new Class[] { StartedEvent.class });
UPLOAD_SUCCEEDED_METHOD = SucceededListener.class.getDeclaredMethod(
"uploadSucceeded", new Class[] { SucceededEvent.class });
} catch (final java.lang.NoSuchMethodException e) {
// This should never happen
throw new java.lang.RuntimeException(
"Internal error finding methods in Upload");
}
}
/**
* Upload.FinishedEvent is sent when the upload receives a file, regardless
* of whether the reception was successful or failed. If you wish to
* distinguish between the two cases, use either SucceededEvent or
* FailedEvent, which are both subclasses of the FinishedEvent.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public static class FinishedEvent extends Component.Event {
/**
* Length of the received file.
*/
private final long length;
/**
* MIME type of the received file.
*/
private final String type;
/**
* Received file name.
*/
private final String filename;
/**
*
* @param source
* the source of the file.
* @param filename
* the received file name.
* @param MIMEType
* the MIME type of the received file.
* @param length
* the length of the received file.
*/
public FinishedEvent(Upload source, String filename, String MIMEType,
long length) {
super(source);
type = MIMEType;
this.filename = filename;
this.length = length;
}
/**
* Uploads where the event occurred.
*
* @return the Source of the event.
*/
public Upload getUpload() {
return (Upload) getSource();
}
/**
* Gets the file name.
*
* @return the filename.
*/
public String getFilename() {
return filename;
}
/**
* Gets the MIME Type of the file.
*
* @return the MIME type.
*/
public String getMIMEType() {
return type;
}
/**
* Gets the length of the file.
*
* @return the length.
*/
public long getLength() {
return length;
}
}
/**
* Upload.FailedEvent event is sent when the upload is received, but the
* reception is interrupted for some reason.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public static class FailedEvent extends FinishedEvent {
private Exception reason = null;
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
* @param exception
*/
public FailedEvent(Upload source, String filename, String MIMEType,
long length, Exception reason) {
this(source, filename, MIMEType, length);
this.reason = reason;
}
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
* @param exception
*/
public FailedEvent(Upload source, String filename, String MIMEType,
long length) {
super(source, filename, MIMEType, length);
}
/**
* Gets the exception that caused the failure.
*
* @return the exception that caused the failure, null if n/a
*/
public Exception getReason() {
return reason;
}
}
/**
* FailedEvent that indicates that an output stream could not be obtained.
*/
public static class NoOutputStreamEvent extends FailedEvent {
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
*/
public NoOutputStreamEvent(Upload source, String filename,
String MIMEType, long length) {
super(source, filename, MIMEType, length);
}
}
/**
* FailedEvent that indicates that an input stream could not be obtained.
*/
public static class NoInputStreamEvent extends FailedEvent {
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
*/
public NoInputStreamEvent(Upload source, String filename,
String MIMEType, long length) {
super(source, filename, MIMEType, length);
}
}
/**
* Upload.SucceededEvent event is sent when the upload is received
* successfully.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public static class SucceededEvent extends FinishedEvent {
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
*/
public SucceededEvent(Upload source, String filename, String MIMEType,
long length) {
super(source, filename, MIMEType, length);
}
}
/**
* Upload.StartedEvent event is sent when the upload is started to received.
*
* @author Vaadin Ltd.
* @since 5.0
*/
public static class StartedEvent extends Component.Event {
private final String filename;
private final String type;
/**
* Length of the received file.
*/
private final long length;
/**
*
* @param source
* @param filename
* @param MIMEType
* @param length
*/
public StartedEvent(Upload source, String filename, String MIMEType,
long contentLength) {
super(source);
this.filename = filename;
type = MIMEType;
length = contentLength;
}
/**
* Uploads where the event occurred.
*
* @return the Source of the event.
*/
public Upload getUpload() {
return (Upload) getSource();
}
/**
* Gets the file name.
*
* @return the filename.
*/
public String getFilename() {
return filename;
}
/**
* Gets the MIME Type of the file.
*
* @return the MIME type.
*/
public String getMIMEType() {
return type;
}
/**
* @return the length of the file that is being uploaded
*/
public long getContentLength() {
return length;
}
}
/**
* Upload.ChangeEvent event is sent when the value (filename) of the upload
* changes.
*
* @since 7.2
*/
public static class ChangeEvent extends Component.Event {
private final String filename;
public ChangeEvent(Upload source, String filename) {
super(source);
this.filename = filename;
}
/**
* Uploads where the event occurred.
*
* @return the Source of the event.
*/
@Override
public Upload getSource() {
return (Upload) super.getSource();
}
/**
* Gets the file name.
*
* @return the filename.
*/
public String getFilename() {
return filename;
}
}
/**
* Receives the events when the upload starts.
*
* @author Vaadin Ltd.
* @since 5.0
*/
public interface StartedListener extends Serializable {
/**
* Upload has started.
*
* @param event
* the Upload started event.
*/
public void uploadStarted(StartedEvent event);
}
/**
* Receives the events when the uploads are ready.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public interface FinishedListener extends Serializable {
/**
* Upload has finished.
*
* @param event
* the Upload finished event.
*/
public void uploadFinished(FinishedEvent event);
}
/**
* Receives events when the uploads are finished, but unsuccessful.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public interface FailedListener extends Serializable {
/**
* Upload has finished unsuccessfully.
*
* @param event
* the Upload failed event.
*/
public void uploadFailed(FailedEvent event);
}
/**
* Receives events when the uploads are successfully finished.
*
* @author Vaadin Ltd.
* @since 3.0
*/
public interface SucceededListener extends Serializable {
/**
* Upload successfull..
*
* @param event
* the Upload successfull event.
*/
public void uploadSucceeded(SucceededEvent event);
}
/**
* Listener for {@link ChangeEvent}
*
* @since 7.2
*/
public interface ChangeListener extends Serializable {
Method FILENAME_CHANGED = ReflectTools.findMethod(ChangeListener.class,
"filenameChanged", ChangeEvent.class);
/**
* A file has been selected but upload has not yet started.
*
* @param event
* the change event
*/
public void filenameChanged(ChangeEvent event);
}
/**
* Adds the upload started event listener.
*
* @param listener
* the Listener to be added, not null
*/
public void addStartedListener(StartedListener listener) {
addListener(StartedEvent.class, listener, UPLOAD_STARTED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addStartedListener(StartedListener)}
**/
@Deprecated
public void addListener(StartedListener listener) {
addStartedListener(listener);
}
/**
* Removes the upload started event listener.
*
* @param listener
* the Listener to be removed.
*/
public void removeStartedListener(StartedListener listener) {
removeListener(StartedEvent.class, listener, UPLOAD_STARTED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeStartedListener(StartedListener)}
**/
@Deprecated
public void removeListener(StartedListener listener) {
removeStartedListener(listener);
}
/**
* Adds the upload received event listener.
*
* @param listener
* the Listener to be added, not null
*/
public void addFinishedListener(FinishedListener listener) {
addListener(FinishedEvent.class, listener, UPLOAD_FINISHED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addFinishedListener(FinishedListener)}
**/
@Deprecated
public void addListener(FinishedListener listener) {
addFinishedListener(listener);
}
/**
* Removes the upload received event listener.
*
* @param listener
* the Listener to be removed.
*/
public void removeFinishedListener(FinishedListener listener) {
removeListener(FinishedEvent.class, listener, UPLOAD_FINISHED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeFinishedListener(FinishedListener)}
**/
@Deprecated
public void removeListener(FinishedListener listener) {
removeFinishedListener(listener);
}
/**
* Adds the upload interrupted event listener.
*
* @param listener
* the Listener to be added, not null
*/
public void addFailedListener(FailedListener listener) {
addListener(FailedEvent.class, listener, UPLOAD_FAILED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addFailedListener(FailedListener)}
**/
@Deprecated
public void addListener(FailedListener listener) {
addFailedListener(listener);
}
/**
* Removes the upload interrupted event listener.
*
* @param listener
* the Listener to be removed.
*/
public void removeFailedListener(FailedListener listener) {
removeListener(FailedEvent.class, listener, UPLOAD_FAILED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeFailedListener(FailedListener)}
**/
@Deprecated
public void removeListener(FailedListener listener) {
removeFailedListener(listener);
}
/**
* Adds the upload success event listener.
*
* @param listener
* the Listener to be added, not null
*/
public void addSucceededListener(SucceededListener listener) {
addListener(SucceededEvent.class, listener, UPLOAD_SUCCEEDED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addSucceededListener(SucceededListener)}
**/
@Deprecated
public void addListener(SucceededListener listener) {
addSucceededListener(listener);
}
/**
* Removes the upload success event listener.
*
* @param listener
* the Listener to be removed.
*/
public void removeSucceededListener(SucceededListener listener) {
removeListener(SucceededEvent.class, listener, UPLOAD_SUCCEEDED_METHOD);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeSucceededListener(SucceededListener)}
**/
@Deprecated
public void removeListener(SucceededListener listener) {
removeSucceededListener(listener);
}
/**
* Adds the upload progress event listener.
*
* @param listener
* the progress listener to be added
*/
public void addProgressListener(ProgressListener listener) {
if (progressListeners == null) {
progressListeners = new LinkedHashSet();
}
progressListeners.add(listener);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addProgressListener(ProgressListener)}
**/
@Deprecated
public void addListener(ProgressListener listener) {
addProgressListener(listener);
}
/**
* Removes the upload progress event listener.
*
* @param listener
* the progress listener to be removed
*/
public void removeProgressListener(ProgressListener listener) {
if (progressListeners != null) {
progressListeners.remove(listener);
}
}
/**
* Adds a filename change event listener
*
* @param listener
* the Listener to add, not null
*/
public void addChangeListener(ChangeListener listener) {
super.addListener(EventId.CHANGE, ChangeEvent.class, listener,
ChangeListener.FILENAME_CHANGED);
}
/**
* Removes a filename change event listener
*
* @param listener
* the listener to be removed
*/
public void removeChangeListener(ChangeListener listener) {
super.removeListener(EventId.CHANGE, ChangeEvent.class, listener);
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeProgressListener(ProgressListener)}
**/
@Deprecated
public void removeListener(ProgressListener listener) {
removeProgressListener(listener);
}
/**
* Emit upload received event.
*
* @param filename
* @param MIMEType
* @param length
*/
protected void fireStarted(String filename, String MIMEType) {
fireEvent(new Upload.StartedEvent(this, filename, MIMEType,
contentLength));
}
/**
* Emits the upload failed event.
*
* @param filename
* @param MIMEType
* @param length
*/
protected void fireUploadInterrupted(String filename, String MIMEType,
long length) {
fireEvent(new Upload.FailedEvent(this, filename, MIMEType, length));
}
protected void fireNoInputStream(String filename, String MIMEType,
long length) {
fireEvent(new Upload.NoInputStreamEvent(this, filename, MIMEType,
length));
}
protected void fireNoOutputStream(String filename, String MIMEType,
long length) {
fireEvent(new Upload.NoOutputStreamEvent(this, filename, MIMEType,
length));
}
protected void fireUploadInterrupted(String filename, String MIMEType,
long length, Exception e) {
fireEvent(new Upload.FailedEvent(this, filename, MIMEType, length, e));
}
/**
* Emits the upload success event.
*
* @param filename
* @param MIMEType
* @param length
*
*/
protected void fireUploadSuccess(String filename, String MIMEType,
long length) {
fireEvent(new Upload.SucceededEvent(this, filename, MIMEType, length));
}
/**
* Emits the progress event.
*
* @param totalBytes
* bytes received so far
* @param contentLength
* actual size of the file being uploaded, if known
*
*/
protected void fireUpdateProgress(long totalBytes, long contentLength) {
// this is implemented differently than other listeners to maintain
// backwards compatibility
if (progressListeners != null) {
for (Iterator it = progressListeners
.iterator(); it.hasNext();) {
ProgressListener l = it.next();
l.updateProgress(totalBytes, contentLength);
}
}
}
/**
* Returns the current receiver.
*
* @return the StreamVariable.
*/
public Receiver getReceiver() {
return receiver;
}
/**
* Sets the receiver.
*
* @param receiver
* the receiver to set.
*/
public void setReceiver(Receiver receiver) {
this.receiver = receiver;
}
/**
* {@inheritDoc}
*/
@Override
public void focus() {
super.focus();
}
/**
* Gets the Tabulator index of this Focusable component.
*
* @see com.vaadin.ui.Component.Focusable#getTabIndex()
*/
@Override
public int getTabIndex() {
return tabIndex;
}
/**
* Sets the Tabulator index of this Focusable component.
*
* @see com.vaadin.ui.Component.Focusable#setTabIndex(int)
*/
@Override
public void setTabIndex(int tabIndex) {
this.tabIndex = tabIndex;
}
/**
* Go into upload state. This is to prevent double uploading on same
* component.
*
* Warning: this is an internal method used by the framework and should not
* be used by user of the Upload component. Using it results in the Upload
* component going in wrong state and not working. It is currently public
* because it is used by another class.
*/
public void startUpload() {
if (isUploading) {
throw new IllegalStateException("uploading already started");
}
isUploading = true;
nextid++;
}
/**
* Interrupts the upload currently being received. The interruption will be
* done by the receiving thread so this method will return immediately and
* the actual interrupt will happen a bit later.
*/
public void interruptUpload() {
if (isUploading) {
interrupted = true;
}
}
/**
* Go into state where new uploading can begin.
*
* Warning: this is an internal method used by the framework and should not
* be used by user of the Upload component.
*/
private void endUpload() {
isUploading = false;
contentLength = -1;
interrupted = false;
markAsDirty();
}
public boolean isUploading() {
return isUploading;
}
/**
* Gets read bytes of the file currently being uploaded.
*
* @return bytes
*/
public long getBytesRead() {
return totalBytes;
}
/**
* Returns size of file currently being uploaded. Value sane only during
* upload.
*
* @return size in bytes
*/
public long getUploadSize() {
return contentLength;
}
/**
* ProgressListener receives events to track progress of upload.
*/
public interface ProgressListener extends Serializable {
/**
* Updates progress to listener
*
* @param readBytes
* bytes transferred
* @param contentLength
* total size of file currently being uploaded, -1 if unknown
*/
public void updateProgress(long readBytes, long contentLength);
}
/**
* @return String to be rendered into button that fires uploading
*/
public String getButtonCaption() {
return buttonCaption;
}
/**
* In addition to the actual file chooser, upload components have button
* that starts actual upload progress. This method is used to set text in
* that button.
*
* In case the button text is set to null, the button is hidden. In this
* case developer must explicitly initiate the upload process with
* {@link #submitUpload()}.
*
* In case the Upload is used in immediate mode using
* {@link #setImmediate(boolean)}, the file choose (html input with type
* "file") is hidden and only the button with this text is shown.
*
*
*
* Note the string given is set as is to the button. HTML
* formatting is not stripped. Be sure to properly validate your value
* according to your needs.
*
* @param buttonCaption
* text for upload components button.
*/
public void setButtonCaption(String buttonCaption) {
this.buttonCaption = buttonCaption;
markAsDirty();
}
/**
* Instructs the upload component to send selected file to the server.
*
* In case developer wants to use this feature, he/she will most probably
* want to hide the upload component's internal submit button by setting its
* caption to null with {@link #setButtonCaption(String)} method.
*
* Note that the upload runs asynchronously. Developer should use normal
* upload listeners to track the process of upload. If the file name field
* is empty, no upload will be triggered.
*
* Also note that the developer should not remove or modify the upload
* component in the same user transaction where the upload submit is
* requested. The upload component can be safely hidden or removed once the
* upload started event has been fired.
*/
public void submitUpload() {
markAsDirty();
getRpcProxy(UploadClientRpc.class).submitUpload();
}
@Override
public void markAsDirty() {
super.markAsDirty();
}
/*
* Handle to terminal via Upload monitors and controls the upload during it
* is being streamed.
*/
private com.vaadin.server.StreamVariable streamVariable;
protected com.vaadin.server.StreamVariable getStreamVariable() {
if (streamVariable == null) {
streamVariable = new com.vaadin.server.StreamVariable() {
private StreamingStartEvent lastStartedEvent;
@Override
public boolean listenProgress() {
return progressListeners != null
&& !progressListeners.isEmpty();
}
@Override
public void onProgress(StreamingProgressEvent event) {
fireUpdateProgress(event.getBytesReceived(),
event.getContentLength());
}
@Override
public boolean isInterrupted() {
return interrupted;
}
@Override
public OutputStream getOutputStream() {
if (getReceiver() == null) {
throw new IllegalStateException(
"Upload cannot be performed without a receiver set");
}
OutputStream receiveUpload = getReceiver().receiveUpload(
lastStartedEvent.getFileName(),
lastStartedEvent.getMimeType());
lastStartedEvent = null;
return receiveUpload;
}
@Override
public void streamingStarted(StreamingStartEvent event) {
startUpload();
contentLength = event.getContentLength();
fireStarted(event.getFileName(), event.getMimeType());
lastStartedEvent = event;
}
@Override
public void streamingFinished(StreamingEndEvent event) {
fireUploadSuccess(event.getFileName(), event.getMimeType(),
event.getContentLength());
endUpload();
if (lastStartedEvent != null) {
lastStartedEvent.disposeStreamVariable();
}
}
@Override
public void streamingFailed(StreamingErrorEvent event) {
try {
Exception exception = event.getException();
if (exception instanceof NoInputStreamException) {
fireNoInputStream(event.getFileName(),
event.getMimeType(), 0);
} else if (exception instanceof NoOutputStreamException) {
fireNoOutputStream(event.getFileName(),
event.getMimeType(), 0);
} else {
fireUploadInterrupted(event.getFileName(),
event.getMimeType(), 0, exception);
}
} finally {
endUpload();
if (lastStartedEvent != null) {
lastStartedEvent.disposeStreamVariable();
}
}
}
};
}
return streamVariable;
}
@Override
public java.util.Collection getListeners(java.lang.Class eventType) {
if (StreamingProgressEvent.class.isAssignableFrom(eventType)) {
if (progressListeners == null) {
return Collections.EMPTY_LIST;
} else {
return Collections.unmodifiableCollection(progressListeners);
}
}
return super.getListeners(eventType);
}
@Override
protected UploadState getState() {
return (UploadState) super.getState();
}
}