java+flex怎么上传文件

java和flex通讯使用的BlazeDs组件.怎么实现flex+java的上传功能,后台使用的是hibernate+spring,没有使用servlet. 最好能写出例子,谢谢!

关于flex上传功能的实现依赖于FileReference类。该类实例对象的创建有两种方法:使用var myFileReference = new FileReference(); FileReferenceList.browse()。使用browse()或者FileReference.browse()方法可以打开上传窗口。
下面部分资源来自互联网,一个简单的上传组件代码,包括了监听ProgressEvent,选择的selectEvent和完成的completeEvent。为了避免硬编码,将urlRequest路径配置在一个xml里面,使用了httpservice进行请求,将结果用于UrlRequest的参数。这个HttpService采用了resultFormat="e4x",那么要求返回来值为XML类型的

Flex上传需要两个包apache common fileupload.jar和apache common io.jar
下载地址
http://jakarta.apache.org/commons/fileupload/
http://commons.apache.org/io/download_io.cgi

upload.mxml
Xml代码

<?xml version="1.0" encoding="utf-8"?>

xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"
creationComplete="init()">

<fx:Declarations>  
    <!-- 将非可视元素(例如服务、值对象)放在此处 -->  
    <mx:HTTPService id="httpService" resultFormat="e4x"/>     
</fx:Declarations>  

<fx:Script>  
    <![CDATA[ 
        import mx.rpc.events.FaultEvent;    
        import mx.rpc.events.ResultEvent;    
        import flash.net.FileReference;    
        import mx.controls.Alert;    
        import mx.events.CloseEvent;    
        import flash.events.*;    

        private var file:FileReference;    

        private var filePath:String="";    
        private function init():void   
        {    
            Security.allowDomain("*");    
            file=new FileReference();    
            file.addEventListener(ProgressEvent.PROGRESS, onProgress);    
            file.addEventListener(Event.SELECT, onSelect);    
            file.addEventListener(Event.COMPLETE,fileUploadCompleteHandler);    

            httpService.url="config.xml";    
            httpService.showBusyCursor=true;    
            httpService.send();    
            httpService.addEventListener(ResultEvent.RESULT,hsResultHandler);    
            httpService.addEventListener(FaultEvent.FAULT,hsFaultHandler);    
        }    

        private function hsResultHandler(e:ResultEvent):void{    
            var xml:XML=e.result as XML;    
            filePath=xml.filepath.@path;    
        }    

        private function hsFaultHandler(e:FaultEvent):void{    
            Alert.show(e.fault.toString(),'http请求错误');    
        }    

        private function fileUploadCompleteHandler(e:Event):void{    
            Alert.show("上传完成");    
            vBox.removeChild(bar);    
        }    

        private function upload():void   
        {    
            var imageTypes:FileFilter=new FileFilter("Images (*.jpg, *.jpeg, *.png)", "*.jpg;*.jpeg;*.png");    
            var docFilter:FileFilter = new FileFilter("Documents", "*.pdf;*.doc;*.txt"); 
            //var viewFilter:FileFilter = new FileFilter("Views", "*.avi;*.flv;*.rmvb"); 
            var allTypes:Array=new Array(imageTypes,docFilter);    
            //              file.browse(allTypes);    
            file.browse();    
        }    

        private function onSelect(e:Event):void   
        {    
            Alert.show("上传 " + file.name + " (共 " + Math.round(file.size) + " 字节)?", "确认上传", Alert.YES | Alert.NO, null, proceedWithUpload);    
        }    

        private function onProgress(e:ProgressEvent):void   
        {    
            lbProgress.text=" 已上传 " + e.bytesLoaded + " 字节,共 " + e.bytesTotal + " 字节";    
            var proc:uint=e.bytesLoaded / e.bytesTotal * 100;    
            bar.setProgress(proc, 100);    
            bar.label="当前进度: " + " " + proc + "%";    
        }    

        private function proceedWithUpload(e:CloseEvent):void   
        {    
            if (e.detail == Alert.YES)    
            {    
                var request:URLRequest=new URLRequest(filePath);    
                try   
                {    
                    file.upload(request);    
                }    
                catch (error:Error)    
                {    
                    trace("上传失败");    
                }    

            }    
        }    


    ]]>  
</fx:Script>  


<mx:Canvas width="100%"    
           height="100%"    
           x="10"    
           y="170"    
           fontSize="15">     
    <mx:VBox width="100%"    
             horizontalAlign="center" id="vBox">     
        <mx:Label id="lbProgress"    
                  text="上传"/>     
        <mx:ProgressBar id="bar"    
                        labelPlacement="bottom"    
                        minimum="0"    
                        visible="true"    
                        maximum="100"    
                        label="当前进度: 0%"    
                        direction="right"    
                        mode="manual"    
                        width="200"/>     

        <mx:Button label="上传文件"    
                   click="upload();"/>     
    </mx:VBox>     
</mx:Canvas>     

/s:Application

config.xml

Xml代码

<?xml version="1.0" encoding="UTF-8"?>





UploadServlet

Java代码

package com.test.upload;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Iterator;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUploadServlet extends HttpServlet {

// 定义文件的上传路径

private String uploadPath = "c:\";

// 限制文件的上传大小

private int maxPostSize = 10000000 * 1024 * 1024;

protected void processRequest(HttpServletRequest request,  
        HttpServletResponse response) throws ServletException, IOException {  
    System.out.println("Access !");  
    System.out.println(uploadPath);  
    // 防止中文乱码  
    request.setCharacterEncoding("utf-8");  
    response.setContentType("text/html;charset=UTF-8");  
    PrintWriter out = response.getWriter();  
    // 保存文件到服务器中  
    DiskFileItemFactory factory = new DiskFileItemFactory();  
    factory.setSizeThreshold(4096);  
    ServletFileUpload upload = new ServletFileUpload(factory);  
    upload.setSizeMax(maxPostSize);  
    try {  
        List fileItems = upload.parseRequest(request);  
        Iterator iter = fileItems.iterator();  
        while (iter.hasNext()) {  
            FileItem item = (FileItem) iter.next();  
            if (!item.isFormField()) {  
                String name = item.getName();  
                System.out.println(name);  
                try {  
                    item.write(new File(uploadPath + name));  
                    // SaveFile s = new SaveFile();  

                    // s.saveFile(name);  

                } catch (Exception e) {  
                    e.printStackTrace();  
                }  
            }  
        }  
    } catch (FileUploadException e) {  
        e.printStackTrace();  
        System.out.println(e.getMessage() + "结束");  
    }  
}  

protected void doGet(HttpServletRequest request,  
        HttpServletResponse response) throws ServletException, IOException {  
    this.doPost(request, response);  
}  

protected void doPost(HttpServletRequest request,  
        HttpServletResponse response) throws ServletException, IOException {  
    processRequest(request, response);  
}  

}

最后,说一下Flex的FileFilter 的用法
FileFilter 类用于指示在调用 FileReference.browse() 方法、FileReferenceList.browse() 方法或调用 File、FileReference 或 FileReferenceList 对象的 browse 方法时显示的文件浏览对话框中显示用户系统上的哪些文件。FileFilter 实例作为可选 typeFilter 参数的值传递给该方法。如果使用 FileFilter 实例,则会滤除 FileFilter 实例中未指定的扩展名和文件类型,即用户无法选择这些类型。如果未向方法传递任何 FileFilter 对象,则对话框中将显示所有文件。
可以采用以下两种方式之一使用 FileFilter 实例:
仅包含 文件扩展名的描述
包含 文件扩展名和 Macintosh 文件类型的描述
这两种格式不能在一个 browse 方法调用中互换。必须使用其中一种格式。
可以向 browse 方法传递一个或多个 FileFilter 实例,如下所示:
var imagesFilter:FileFilter = new FileFilter("Images", "*.jpg;*.gif;*.png");
var docFilter:FileFilter = new FileFilter("Documents", "*.pdf;*.doc;*.txt");
var myFileReference:FileReference = new FileReference();
myFileReference.browse([imagesFilter, docFilter]);
或者在 AIR 应用程序中:
var imagesFilter:FileFilter = new FileFilter("Images", "*.jpg;*.gif;*.png");
var docFilter:FileFilter = new FileFilter("Documents", "*.pdf;*.doc;*.txt");
var myFile:File = new File();
myFile.browseForOpen("Open", [imagesFilter, docFilter]);
var imagesFilter = new air.FileFilter("Images", "*.jpg;*.gif;*.png");
var docFilter = new air.FileFilter("Documents", "*.pdf;*.doc;*.txt");
var myFile = new air.File();
myFile.browseForOpen("Open", [imagesFilter, docFilter]);
FileFilter.extension 属性中的扩展名列表用于筛选文件浏览对话框中显示的文件。该列表实际并不显示在对话框中;若要对用户显示文件类型,必须在描述字符串以及扩展名列表中列出文件类型。