flex实现pdf，word以及图片格式的预览（包括bmp格式的）

之前用flash.display.Loader，不支持bmp文件的预览。现在修改服务器java的代码，flex通过请求html来预览pdf以及所有图片格式

注意：因为是预览不是在线，所有Content-Disposition要设置成inline，不要设置成附件attachment

客户端flex的设置

var parm:Object = _showFileItem.getPostParam(false);
     var showPicURL:URLRequest = new URLRequest();
     var postData:URLVariables = new URLVariables();  
     postData.serverFileName = _showFileItem.serverFileName;
     postData.serverFilePath = _showFileItem.serverFilePath;
     showPicURL.data = postData;
     showPicURL.url = parm["showPicUrl"];  //请求后天的服务 路径比如是http://192.168.1.100:8080/ZFS/showPicture.do

     var filetype:String = _showFileItem.serverFileName.toString();
     var fileFilt:String =filetype.substring(filetype.lastIndexOf(".")+1,filetype.length);
     if(fileFilt=="pdf"||fileFilt=="gif" || fileFilt=="jpg" || fileFilt=="bmp" || fileFilt=="png"){
      showPicURL.method=URLRequestMethod.POST;
      navigateToURL(showPicURL,"_blank");
     }else{
      Alert.show("只支持图片格式！","提示");
     }

服务器java代码如下：

package com.zhan.fileupload;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ShowFile extends HttpServlet{
 /**
  *
  */
 private static final long serialVersionUID = 3089316329737765177L;

 public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
  doPost(request,response);
 }
 
 public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
  try {
   downLoad(request,response);
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 
 private void downLoad(HttpServletRequest request,HttpServletResponse response) throws Exception {

//  BufferedOutputStream bos = null;
//  BufferedInputStream  bis = null;
  
  String serverFilePath = request.getParameter("serverFilePath");
  if(serverFilePath!=null)
   serverFilePath = new String(serverFilePath.getBytes("ISO8859-1"),"utf-8");
  
  String serverFileName = request.getParameter("serverFileName");
  if(serverFileName!=null)
   serverFileName = new String(serverFileName.getBytes("ISO8859-1"),"utf-8");
  
  System.out.print(serverFilePath+serverFileName);
   
  String fileName = serverFilePath + serverFileName;
  
  BufferedInputStream br = null;
  OutputStream out = null;
  
  //查看文档
  try{
   File f = new File(fileName);
   System.out.println(f.getName());
   if(!f.exists()){
    response.sendError(404,"File not found!");
    return;
   }
   br = new BufferedInputStream(new FileInputStream(f));
   byte[] buf = new byte[1024];
   int len = 0;

   response.reset(); //非常重要
   
   //文 件类型
   if(serverFileName.toUpperCase().lastIndexOf(".pdf".toUpperCase())!=-1){
    
    response.setContentType("application/pdf");
   }
   else if(serverFileName.toUpperCase().lastIndexOf(".doc".toUpperCase())!=-1
     ||
     serverFileName.toUpperCase().lastIndexOf(".docx".toUpperCase())!=-1){
    response.setContentType("application/msword");
   }
   else if(serverFileName.toUpperCase().lastIndexOf(".xls".toUpperCase())!=-1){
    response.setContentType("application/vnd.ms-excel");
    
   }else if(serverFileName.toUpperCase().lastIndexOf(".ppt".toUpperCase())!=-1){
    response.setContentType("application/vnd.ms-powerpoint");
    
   }else if(serverFileName.toUpperCase().lastIndexOf(".jpg".toUpperCase())!=-1
     ){
    
    response.setContentType("image/jpg;");
   }
   else if(
     serverFileName.toUpperCase().lastIndexOf(".png".toUpperCase())!=-1
     ){
    
    response.setContentType("image/png;");
   }
   else if(
     serverFileName.toUpperCase().lastIndexOf(".gif".toUpperCase())!=-1
     ){
    
    response.setContentType("image/gif;");
   }
   else if(
     
     serverFileName.toUpperCase().lastIndexOf(".bmp".toUpperCase())!=-1){
    
    response.setContentType("image/bmp;");
   }
   
   response.setHeader("Content-Disposition", "inline;  filename=" + new String(f.getName().getBytes("GBK"),"ISO8859-1"));
   response.setHeader("Pragma", "No-cache");
   response.setHeader("Cache-Control", "No-cache");
   response.setDateHeader("Expires", 0);
   out = response.getOutputStream();
   while((len = br.read(buf)) >0){
    out.write(buf,0,len);
   }
   out.flush();
   
  }catch(Exception e){
   e.printStackTrace();
  }finally{
   if(br!=null){  
    br.close();
   }
   if(out!=null){
    out.close();
   }  
  } }

}

补充以前的实现方案：

之前的通过服务器返回字节流，flex的调用Image显示，下面是部分代码

 

private var stream:URLStream = new URLStream();
   private var bytes:ByteArray = new ByteArray();

var showPicURL:URLRequest = new URLRequest();
     var postData:URLVariables = new URLVariables();  
     postData.serverFileName = fileItem.serverFileName;
     postData.serverFilePath = fileItem.serverFilePath;
     showPicURL.data = postData;
     showPicURL.url = parm["showPicUrl"];   //请求后天的服务 路径比如是http://192.168.1.100:8080/ZFS/showPicture.do

stream.addEventListener(Event.COMPLETE, onLoadComplete);
      stream.load(showPicURL);

private function onLoadComplete(event:Event):void
   {
    if (stream.connected)
    {
     var b:int;
     try {
      do {
       b = stream.readByte();
       bytes.writeByte(b);
      } while (true);
     } catch (e:EOFError) {
      //Alert.show(bytes.length.toString());
     }
    }
    var loaderPic:Loader = new Loader();//Loader 类可用于加载 SWF 文件或图像（JPG、PNG 或 GIF）文件

    loaderPic.loadBytes(bytes);
    showImage.addChild(loaderPic);   //showImage是flex的Image组件id
   }

 

后台java文件是：

package com.zhan.fileupload;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ShowPic extends HttpServlet {

 /**
  *
  */
 private static final long serialVersionUID = 3089316329737765177L;

 public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{
  doPost(request,response);
 }
 
 public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
  try {
   downLoad(request,response);
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 
 private void downLoad(HttpServletRequest request,HttpServletResponse response) throws Exception {

  BufferedOutputStream bos = null;
  BufferedInputStream  bis = null;
  
  String serverFilePath = request.getParameter("serverFilePath");
  if(serverFilePath!=null)
   serverFilePath = new String(serverFilePath.getBytes("ISO8859-1"),"utf-8");
  
  String serverFileName = request.getParameter("serverFileName");
  if(serverFileName!=null)
   serverFileName = new String(serverFileName.getBytes("ISO8859-1"),"utf-8");
  
  System.out.print(serverFilePath+serverFileName);
  
  String PicObject = serverFilePath + serverFileName;
  try {
            bis = new BufferedInputStream(new FileInputStream(PicObject));         
            bos = new BufferedOutputStream(response.getOutputStream());
           
            byte[] buff = new byte[2048];
            int bytesRead;

            while(-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff,0,bytesRead);
            }
        } catch(final IOException e) {
         e.printStackTrace();
        } catch(Exception e) {
         e.printStackTrace();
        }finally {
            if (bis != null)
                bis.close();
            if (bos != null)
            {
                bos.flush();
                bos.close();
                bos=null;
            }
        }
        response.flushBuffer();
 }
}