Ho usato questo strumento prima:
http://code.google.com/p/gwt-fileapi/
a differenza degli altri suggerimenti qui, non solo si dà l'API appropriata per mostrare avanzamento del caricamento, ma dà anche la possibilità di fare upload in batch selezionando m file multipli e fornisce anche il supporto per il trascinamento della selezione. Ha anche un meccanismo di fallback pre HTML5.
Ho avuto molta fortuna con esso gwt-fileap. Recentemente si è rotto in Firefox 7 e 8 e ho dovuto applicare questa patch ad esso - ma per il resto funziona davvero grande:
@@ -57,26 +57,33 @@
/**
* gets the filename
- *
+ *
* @return the filename
*/
public final native String getFileName() /*-{
- return this.fileName;
+ if(this.name)
+ return this.name;
+ else
+ return this.fileName;
+
}-*/;
/**
* gets the file size in bytes
- *
+ *
* @return the file size in bytes
*/
public final native int getFileSize() /*-{
- return this.fileSize;
+ if(this.size)
+ return this.size;
+ else
+ return this.fileSize;
}-*/;
/**
* gets the MIME type of the file, may be null if the browser cannot detect
* the type
ho dovuto anche aggiungere le seguenti linee al http://code.google.com/p/gwt-fileapi/source/browse/trunk/gwt-fileapi/src/com/gwtpro/html5/fileapi/Html5FileApi.gwt.xml - queste linee descrivono come il meccanismo di fallback lavori. Puoi fare qualcosa di simile se vuoi che il tuo codice ricada sull'implementazione di SWFUploader mostrata sotto nel caso in cui manchi HTML5.
<define-property name="fileapi.support" values="yes,no" />
<property-provider name="fileapi.support"><![CDATA[
var input=document.createElement('input');
input.setAttribute('type','file');
return input.files==null?'no':'yes';
]]></property-provider>
<replace-with
class="com.gwtpro.html5.fileapi.client.ui.FileInput.FileInputImplHtml5">
<when-type-is
class="com.gwtpro.html5.fileapi.client.ui.FileInput.FileInputImpl" />
<when-property-is name="fileapi.support" value="yes" />
<any>
<when-property-is name="user.agent" value="ie8" />
<when-property-is name="user.agent" value="safari" />
<when-property-is name="user.agent" value="gecko1_8" />
<when-property-is name="user.agent" value="opera" />
<when-property-is name="user.agent" value="chrome" />
</any>
</replace-with>
Questo è come io lo uso nella mia domanda:
Questa è l'interfaccia che descrive l'astrazione:
public interface FileUpload {
public void uploadFiles();
public Widget getWidget();
public void initialize(Grid updateTable, Uploader uploader, String url, boolean createDropHandler);
public void setDisabled(boolean b);
public void readyToPaint();
public void reset();
}
Quello che segue è l'attuazione GWT-FileAPI dell'interfaccia:
Questa è l'implementazione di SWFUpload http://code.google.com/p/swfupload-gwt/ dello stesso Interfaccia:
package com.hierarchycm.gxt.client.fileUpload;
import com.extjs.gxt.ui.client.widget.Html;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.Widget;
public class FileUploadSwfImpl extends Html implements FileUpload {
SwfUploadUtil swfUploadUtil = null;
private Uploader uploader;
private String url;
private boolean createDropHandler;
private Grid updateTable;
static int uploadId = 0;
static String divTagId;
public FileUploadSwfImpl() {
divTagId = "swfupload" + uploadId++;
String divTag = "<div id=\"" + divTagId + "\"></div";
this.setHtml(divTag);
}
@Override
public void uploadFiles() {
swfUploadUtil.startUpload();
}
@Override
public Widget getWidget() {
return this;
}
public void readyToPaint() {
swfUploadUtil = new SwfUploadUtil(uploader, updateTable, divTagId, url);
}
@Override
public void initialize(Grid updateTable, Uploader uploader, String url, boolean createDropHandler) {
this.uploader = uploader;
this.url = url;
this.createDropHandler = createDropHandler;
this.updateTable = updateTable;
}
@Override
public void setDisabled(boolean b) {
swfUploadUtil.setDisabled(b);
this.disabled = true;
}
@Override
public void reset() {
swfUploadUtil.reset();
}
}
E questo è l'utilità della FileUploadSwfImpl dipende da:
package com.hierarchycm.gxt.client.fileUpload;
import java.util.HashMap;
import org.swfupload.client.File;
import org.swfupload.client.SWFUpload;
import org.swfupload.client.UploadBuilder;
import org.swfupload.client.SWFUpload.ButtonAction;
import org.swfupload.client.SWFUpload.ButtonCursor;
import org.swfupload.client.event.DialogStartHandler;
import org.swfupload.client.event.FileDialogCompleteHandler;
import org.swfupload.client.event.FileQueuedHandler;
import org.swfupload.client.event.UploadCompleteHandler;
import org.swfupload.client.event.UploadErrorHandler;
import org.swfupload.client.event.UploadProgressHandler;
import org.swfupload.client.event.UploadSuccessHandler;
import org.swfupload.client.event.FileDialogCompleteHandler.FileDialogCompleteEvent;
import org.swfupload.client.event.FileQueuedHandler.FileQueuedEvent;
import org.swfupload.client.event.UploadCompleteHandler.UploadCompleteEvent;
import org.swfupload.client.event.UploadErrorHandler.UploadErrorEvent;
import org.swfupload.client.event.UploadProgressHandler.UploadProgressEvent;
import org.swfupload.client.event.UploadSuccessHandler.UploadSuccessEvent;
import com.extjs.gxt.ui.client.widget.form.TextArea;
import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Grid;
public class SwfUploadUtil {
HashMap<String, Integer> filenameRowHm = new HashMap<String, Integer>();
private boolean resetIssued;
SWFUpload swfUpload = null;
private HashMap <String, File> files = new HashMap<String, File>();
int tableRow = 5;
Uploader uploader = null;
private Grid updateTable;
private String divName;
private String url;
synchronized private void removeFile(String id) {
files.remove(id);
}
public SwfUploadUtil(Uploader uploader, Grid updateTable, String divName, String url){
reset();
this.uploader = uploader;
this.updateTable = updateTable;
this.divName = divName;
this.url = url;
this.swfUpload = loadSWFUpload();
updateTable.resize(5, 5);
updateTable.setText(2, 0, "Upload URL:");
updateTable.setText(2, 1, url);
updateTable.setText(4, 0, "File Name");
updateTable.setText(4, 1, "Bytes In");
updateTable.setText(4, 2, "Status");
updateTable.setText(4, 3, "File Size");
updateTable.setText(4, 4, "Server response");
}
public SWFUpload loadSWFUpload() {
this.updateTable = updateTable;
if (swfUpload == null) {
final UploadBuilder builder1 = new UploadBuilder();
builder1.setHTTPSuccessCodes(200, 201);
builder1.setFileTypes("*.webm;*.asf;*.wma;*.wmv;*.avi;*.flv;*.swf;*.mpg;*.mpeg;*.mp4;*.mov;*.m4v;*.aac;*.mp3;*.wav;*.png;*.jpg;*.jpeg;*.gif");
builder1.setFileTypesDescription("Images, Video & Sound");
builder1.setButtonPlaceholderID(divName);
builder1.setButtonImageURL("./images/XPButtonUploadText_61x22.png");
builder1.setButtonCursor(ButtonCursor.HAND);
builder1.setButtonWidth(61);
builder1.setButtonHeight(22);
builder1.setButtonAction(ButtonAction.SELECT_FILES);
builder1.setUploadProgressHandler(new UploadProgressHandler() {
public void onUploadProgress(UploadProgressEvent e) {
File f = e.getFile();
updateTable.setText(getFilenameRow(f), 2, String.valueOf(e.getBytesComplete()));
}
});
builder1.setUploadSuccessHandler(new UploadSuccessHandler() {
public void onUploadSuccess(UploadSuccessEvent e) {
File f = e.getFile();
updateTable.setText(getFilenameRow(f), 4, e.getServerData());
}
});
builder1.setUploadErrorHandler(new UploadErrorHandler() {
public void onUploadError(UploadErrorEvent e) {
File ff = e.getFile();
String message = e.getMessage();
if (message == null || message.trim().length() == 0) {
message = "upload failed";
}
updateTable.setText(getFilenameRow(ff), 2, String.valueOf(message));
removeFile(ff.getId());
if (files.values().size() > 0) {
ff = files.values().iterator().next();
updateTable.setText(getFilenameRow(ff), 2, "Started");
swfUpload.startUpload(ff.getId());
}
}
});
builder1.setUploadURL(url);
builder1.setDialogStartHandler(new DialogStartHandler() {
@Override
public void onDialogStart() {
if(resetIssued == true) {
filenameRowHm.clear();
resetIssued = false;
}
}
}
);
builder1.setUploadCompleteHandler(new UploadCompleteHandler() {
public void onUploadComplete(UploadCompleteEvent e) {
File f = e.getFile();
updateTable.setText(getFilenameRow(f), 2, "Done");
removeFile(f.getId());
if (files.values().size() > 0) {
File ff = files.values().iterator().next();
updateTable.setText(getFilenameRow(ff), 2, "Started");
swfUpload.startUpload(ff.getId());
} else {
uploader.uploadDoneEventHandler();
}
}
});
builder1.setFileQueuedHandler(new FileQueuedHandler() {
public void onFileQueued(FileQueuedEvent event) {
File f = event.getFile();
updateTable.setText(getFilenameRow(f), 2, "Queued");
files.put(f.getId(), f);
}
});
builder1.setFileDialogCompleteHandler(new FileDialogCompleteHandler() {
public void onFileDialogComplete(FileDialogCompleteEvent e) {
updateTable.setText(2, 0, "Number of files");
updateTable.setText(2, 1, String.valueOf(files.values().size()));
for(File f : files.values()) {
getFilenameRow(f);
}
if (files.values().size() > 0) {
for (String paramName : uploader.getPostParams().keySet()) {
swfUpload.addPostParam(paramName,uploader.getPostParams().get(paramName));
}
}
}
});
swfUpload = builder1.build();
}
return swfUpload;
}
public int getFilenameRow (File f) {
Integer filenamerow = filenameRowHm.get(f.getId());
if (filenamerow == null) {
updateTable.resize(tableRow+1, 5);
filenamerow = new Integer(tableRow++);
updateTable.setText(filenamerow.intValue(), 0, f.getName());
updateTable.setText(filenamerow.intValue(), 3, String.valueOf(f.getSize()));
//updateTable.setText(filenamerow.intValue(), 3, String.valueOf(f));
filenameRowHm.put(f.getId(), filenamerow);
}
return filenamerow.intValue();
}
public void startUpload() {
uploader.uploadStartedEventHandler();
swfUpload.startUpload();
}
public void setDisabled(boolean disabled) {
swfUpload.setButtonDisabled(disabled);
}
public void reset() {
// TODO Auto-generated method stub
resetIssued = true;
}
}
sì, questo è quello che ho finito per usare alla fine. È molto facile da installare e integrare. – codingbear
La barra di avanzamento non funziona con GAE (vedi http://code.google.com/p/gwtupload/issues/detail?id=111) –
gwtupload è stato corretto per GAE http://code.google.com/p/gwtupload/source/dettaglio? r = 926 – Ena