multifileupload.as

多文件上传,前面flex界面.后台php处理的,可自己修改成java

                _file = FileReference(_files.getItemAt(0));    
                _file.addEventListener(Event.OPEN, openHandler);
                _file.addEventListener(ProgressEvent.PROGRESS, progressHandler);
                _file.addEventListener(Event.COMPLETE, completeHandler);
                _file.addEventListener(SecurityErrorEvent.SECURITY_ERROR,securityErrorHandler);
                _file.addEventListener(HTTPStatusEvent.HTTP_STATUS,httpStatusHandler);
                _file.addEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);
                _file.upload(_uploadURL);
                 setupCancelButton(true);
            }
        }
        
        //Remove Selected File From Cue
        private function removeSelectedFileFromCue(event:Event):void{
           
            if (_datagrid.selectedIndex >= 0){
            _files.removeItemAt( _datagrid.selectedIndex);
            }
        }


		 //Remove all files from the upload cue;
        private function clearFileCue(event:Event):void{
       
            _files.removeAll();
        }
		
		// Cancel Current File Upload
        private function cancelFileIO(event:Event):void{
        	
            _file.cancel();
            setupCancelButton(false);
            checkCue();
            
        }    
    
       


		//label function for the datagird File Size Column
        private function bytesToKilobytes(data:Object,blank:Object):String {
            var kilobytes:String;
            kilobytes = String(Math.round(data.size/ 1024)) + ' kb';
            return kilobytes
        }
        
        
        // Feed the progress bar a meaningful label
        private function getByteCount():void{
	        var i:int;
	        _totalbytes = 0;
	            for(i=0;i < _files.length;i++){
	            _totalbytes +=  _files[i].size;
	            }
	        _progressbar.label = "Total Files: "+  _files.length+ " Total Size: " + Math.round(_totalbytes/1024) + " kb"
        }        
        
        // Checks the files do not exceed maxFileSize | if _maxFileSize == 0 No File Limit Set
        private function checkFileSize(filesize:Number):Boolean{
      
        	var r:Boolean = false;
        		//if  filesize greater then _maxFileSize
		        if (filesize > _maxFileSize){
		        	r = false;
		        	trace("false");
		       	 }else if (filesize <= _maxFileSize){
		        	r = true;
		        	trace("true");
	        	}
	        	
	        	if (_maxFileSize == 0){
	        	r = true;
	        	}
	   	
        	return r;
        }
        
        // restores progress bar back to normal
        private function resetProgressBar():void{
        
                  _progressbar.label = "";
                 _progressbar.maximum = 0;
                 _progressbar.minimum = 0;
        }
        
        // reset form item elements
        private function resetForm():void{
            _uploadbutton.enabled = false;
            _uploadbutton.addEventListener(MouseEvent.CLICK,uploadFiles);
            _uploadbutton.label = "Upload";
            _progressbar.maximum = 0;
            _totalbytes = 0;
            _progressbar.label = "";
            _remselbutton.enabled = false;
            _remallbutton.enabled = false;
            _browsebutton.enabled = true;
        }
        
        // whenever the _files arraycollection changes this function is called to make sure the datagrid data jives
        private function popDataGrid(event:CollectionEvent):void{                
            getByteCount();
            checkCue();
        }
        
       // enable or disable upload and remove controls based on files in the cue;        
        private function checkCue():void{
             if (_files.length > 0){
                _uploadbutton.enabled = true;
                _remselbutton.enabled = true;
                _remallbutton.enabled = true;            
             }else{
                resetProgressBar();
                _uploadbutton.enabled = false;     
             }    
        }

    	// toggle upload button label and function to trigger file uploading or upload cancelling
        private function setupCancelButton(x:Boolean):void{
            if (x == true){
                _uploadbutton.label = "Cancel";
                _browsebutton.enabled = false;
                _remselbutton.enabled = false;
                _remallbutton.enabled = false;
                _uploadbutton.addEventListener(MouseEvent.CLICK,cancelFileIO);        
            }else if (x == false){
                _uploadbutton.removeEventListener(MouseEvent.CLICK,cancelFileIO);
                 resetForm();
            }
        }
        

       /*********************************************************
       *  File IO Event Handlers                                *
       *********************************************************/
      
        //  called after user selected files form the browse dialouge box.
        private function selectHandler(event:Event):void {
            var i:int;
            var msg:String ="";
            var dl:Array = [];                          
	            for (i=0;i < event.currentTarget.fileList.length; i ++){
	            	if (checkFileSize(event.currentTarget.fileList[i].size)){
	                _files.addItem(event.currentTarget.fileList[i]);
	                trace("under size " + event.currentTarget.fileList[i].size);
	            	}  else {
	            	dl.push(event.currentTarget.fileList[i]);
	            	trace(event.currentTarget.fileList[i].name + " too large");
	            	}
	            }	            
	            if (dl.length > 0){
	            	for (i=0;i<dl.length;i++){
	            	msg += String(dl[i].name + " is too large. \n");
	            	}
	            	mx.controls.Alert.show(msg + "Max File Size is: " + Math.round(_maxFileSize / 1024) + " kb","File Too Large",4,null).clipContent;
	            }        
        }        
        
        // called after the file is opened before upload    
        private function openHandler(event:Event):void{
            trace('openHandler triggered');
            _files;
        }
        
        // called during the file upload of each file being uploaded | we use this to feed the progress bar its data
        private function progressHandler(event:ProgressEvent):void {        
            _progressbar.setProgress(event.bytesLoaded,event.bytesTotal);
            _progressbar.label = "Uploading " + Math.round(event.bytesLoaded / 1024) + " kb of " + Math.round(event.bytesTotal / 1024) + " kb " + (_files.length - 1) + " files remaining";
        }

        // called after a file has been successully uploaded | we use this as well to check if there are any files left to upload and how to handle it
        private function completeHandler(event:Event):void{
            //trace('completeHanderl triggered');
            _files.removeItemAt(0);
            if (_files.length > 0){
            	_totalbytes = 0;
                uploadFiles(null);
            }else{
                setupCancelButton(false);
                 _progressbar.label = "Uploads Complete";
                 var uploadCompleted:Event = new Event(Event.COMPLETE);
                dispatchEvent(uploadCompleted);
            }
        }    
          
        // only called if there is an  error detected by flash player browsing or uploading a file   
        private function ioErrorHandler(event:IOErrorEvent):void{
            //trace('And IO Error has occured:' +  event);
            mx.controls.Alert.show(String(event),"ioError",0);
        }    
        // only called if a security error detected by flash player such as a sandbox violation
        private function securityErrorHandler(event:SecurityErrorEvent):void{
            //trace("securityErrorHandler: " + event);
            mx.controls.Alert.show(String(event),"Security Error",0);
        }
        
        //  This function its not required
        private function cancelHandler(event:Event):void{
            // cancel button has been clicked;
            trace('cancelled');
        }
        
        //  after a file upload is complete or attemted the server will return an http status code, code 200 means all is good anything else is bad.
        private function httpStatusHandler(event:HTTPStatusEvent):void {
        //        trace("httpStatusHandler: " + event);
            if (event.status != 200){
                mx.controls.Alert.show(String(event),"Error",0);
            }
        }

        
    }
}