ajax上传图片(struts1.2)

一.sample.html(提交页面)

<form name="upfile_form" action="singertonUploadAction" method="POST" enctype="multipart/form-data">
      <input type="file" name="upload_file" id="upload_file" onchange="checkFileSize(this);" />
 
  <p>
   <input type="submit" value="submit" />
  </p>
  <iframe name="check_file_frame" style="display:none;"></iframe>
</form>

 

二.

public class SingertonUploadForm extends ActionForm {

 private FormFile upload_file;

 public FormFile getUpload_file() {
  return upload_file;
 }

 public void setUpload_file(FormFile upload_file) {
  this.upload_file = upload_file;
 }
 
}

三.

public class SingertonUploadAction extends Action {

  private static String UPLOAD_FILE_PATH = "c:/";

     @Override
     public ActionForward execute(ActionMapping mapping, ActionForm form,
             HttpServletRequest request, HttpServletResponse response) throws Exception {
      SingertonUploadForm  uploadForm = (SingertonUploadForm)form;
         //得到上传的文件
         FormFile uploadFile = uploadForm.getUpload_file();
         //得到文件名
         String fileName = uploadFile.getFileName();
         //得到文件大小
         int fileSize = uploadFile.getFileSize();
         System.out.println("FileName = " + fileName);
         System.out.println("FileSize=" + fileSize);
         boolean result = true;
         try{
             //得到文件的输入流
             InputStream is = uploadFile.getInputStream();
             //上传文件
             uploadFile(fileName,is);
         }catch(IOException ex){
             ex.printStackTrace();
             //假如上传文件失败，设置一个失败的标记位
             result = false;
         }
         if(result){
             return mapping.findForward("success");
         } else {
             return mapping.findForward("fail");
         }       
     }
    
     /**
      * 上传文件
      * @param fileName
      * @param is
      * @throws IOException
      */
     private void uploadFile(String fileName,InputStream is) throws IOException{
         OutputStream os = new FileOutputStream(UPLOAD_FILE_PATH + fileName);
         //8k缓存数据
         byte[] buffer = new byte[1024 * 8];
         //设置读进缓存的字节数
         int len;
         while((len=is.read(buffer))!=-1){
             //将缓存数据写入磁盘
             os.write(buffer,0,len);
         }
         //关闭输出流
         os.close();
         //关闭输入流
         is.close();
     }

 }

四.类似ajax提交需要check_file.js

 

var fileForm = new Object();
function checkFileSize(fileObj) {
  if(fileObj.value != "") {
    var form = document.forms['upfile_form'];

    //把form的原始数据缓存起来
    fileForm.f = form;
    fileForm.a = form.getAttribute("action");  //form.action 为一个静态的对象，所以这里要使用getAttribute方法取值
    fileForm.t = form.target;

    //请求服务器端
    form.target = "check_file_frame";
    //form.action = "./ajax.php?act=upload";
    form.action = "singertonUploadAction.do";
    //form.submit(); 其实上面的action已经会执行submit操作，这步可有可无
  }
  return false;
}

function ajax_callback(result) {
  //还原form属性
  fileForm.f.target = fileForm.t;
  fileForm.f.setAttribute("action", fileForm.a);

  //处理结果
  switch(result) {
    case 0:
      alert("文件超过了200K或者没有选择文件，请重新上传！");
      //todo somthing
    default :
      alert("合法");
      //do somthing，如果你想使用这种方法实现真正的上传的话，那么在成功后把返回的文件路经存储在一个 input[hidden]里是个不错的办法
  }
  return ;
}