JFinal使用ajaxfileupload实现图片上传及预览

<script type="text/javascript" src="<%=request.getContextPath() %>/js/jquery.min.js"></script><script type="text/javascript" src="<%=request.getContextPath() %>/media/ajaxupload/ajaxfileupload.js"></script>

<input type="file" class="upload" name="file" id="upfile" onchange="ajaxFileUpload('upfile')"/><!--用于预览图片--> <img src="<c:if test="${banner.img!=null}"><%=request.getContextPath() %>/media/file/${banner.img}</c:if>" style="width:300px;height:100px;" id="imgsrc"/><!--存放图片路径,提交页面时传给后台的值--><input id='imgurl' type='hidden' name="imgurl" style="height:30px;width:100%" value='${banner.img}'/>

function ajaxFileUpload(fileEid, paramdata){ if(typeof(paramdata)=='undefined') paramdata = {}; var $file=$('#'+fileEid).val(); if($file=='') {alert("请先选择对应的上传文件，谢谢"); return;} $.ajaxFileUpload({ url:'<%=request.getContextPath()%>/banner/uploadpic', secureuri:false, fileElementId:fileEid, dataType: 'text', data:paramdata, success: function (result){  var result = result.substring(result.indexOf("{"),result.indexOf("}")+1);  result = eval("("+result+")");  if(result.t==1){  $("#imgsrc").attr("src","<%=request.getContextPath() %>/media/file/"+result.msg);  $("#imgurl").val(result.msg);  }else{  alert("上传失败");  } } });}

public void uploadpic(){ UploadFile upfile = getFile();//JFinal规定getFile()必须最先执行 File file = upfile.getFile(); String filename = file.getName(); String delfilename = filename; if(filename!=null && !filename.equals("")){ filename = new SimpleDateFormat("yyyyMMddkkmmss").format(new Date())+filename; /**  * 新保存的位置  */ String path = getRequest().getSession().getServletContext()  .getRealPath("/"); String newPath = "/media/file/";//自定义目录 用于存放图片 /**  * 没有则新建目录  */ File floder = new File(path + newPath); if (!floder.exists()) {  floder.mkdirs(); } /**  * 保存新文件  */ FileInputStream fis = null; FileOutputStream fos = null; try{  File savePath = new File(path + newPath + filename);  if(!savePath.isDirectory()) savePath.createNewFile();  fis = new FileInputStream(file);  fos = new FileOutputStream(savePath);  byte[] bt = new byte[300];  while (fis.read(bt, 0, 300) != -1) {  fos.write(bt, 0, 300);  } }catch(Exception e){  e.printStackTrace(); }finally{  try{  if(null!=fis) fis.close();  if(null!=fos) fos.close();  }catch(Exception e){  e.printStackTrace();  } } /**  * 删除原图片，JFinal默认上传文件路径为 /upload（自动创建）  */ File delFile = new File(path+"/upload/"+delfilename); if(delFile.exists()){  delFile.delete(); } setAttr("msg",filename); setAttr("t",1); }else{ setAttr("t",0); } renderJson();}

jQuery.extend({ createUploadIframe: function(id, uri) { //create frame var frameId = 'jUploadFrame' + id; var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"'; if(window.ActiveXObject) {  if(typeof uri== 'boolean'){  iframeHtml += ' src="' + 'javascript:false' + '"';  } else if(typeof uri== 'string'){  iframeHtml += ' src="' + uri + '"';  }  } iframeHtml += ' />'; jQuery(iframeHtml).appendTo(document.body); return jQuery('#' + frameId).get(0); }, createUploadForm: function(id, fileElementId, data) { //create form  var formId = 'jUploadForm' + id; var fileId = 'jUploadFile' + id; var form = jQuery('<form action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');  if(data) {  for(var i in data) {  jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);  } } var oldElement = jQuery('#' + fileElementId); var newElement = jQuery(oldElement).clone(); jQuery(oldElement).attr('id', fileId); jQuery(oldElement).before(newElement); jQuery(oldElement).appendTo(form); //set attributes jQuery(form).css('position', 'absolute'); jQuery(form).css('top', '-1200px'); jQuery(form).css('left', '-1200px'); jQuery(form).appendTo('body');  return form; }, ajaxFileUpload: function(s) { // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout  s = jQuery.extend({}, jQuery.ajaxSettings, s); var id = new Date().getTime()  var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data)); var io = jQuery.createUploadIframe(id, s.secureuri); var frameId = 'jUploadFrame' + id; var formId = 'jUploadForm' + id; // Watch for a new set of requests if ( s.global && ! jQuery.active++ ) {  jQuery.event.trigger( "ajaxStart" ); }   var requestDone = false; // Create the request object var xml = {}  if ( s.global )  jQuery.event.trigger("ajaxSend", [xml, s]); // Wait for a response to come back var uploadCallback = function(isTimeout) {    var io = document.getElementById(frameId);  try {  if(io.contentWindow) {   xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;   xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;  } else if(io.contentDocument) {   xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;   xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;  }  } catch(e) {  jQuery.handleError(s, xml, null, e);  }  if ( xml || isTimeout == "timeout") {  requestDone = true;  var status;  try {   status = isTimeout != "timeout" ? "success" : "error";   // Make sure that the request was successful or notmodified   if ( status != "error" ) {   // process the data (runs the xml through httpData regardless of callback)   var data = jQuery.uploadHttpData( xml, s.dataType );    // If a local callback was specified, fire it and pass it the data   if ( s.success )    s.success( data, status );   // Fire the global callback   if( s.global )    jQuery.event.trigger( "ajaxSuccess", [xml, s] );   } else   jQuery.handleError(s, xml, status);  } catch(e) {   status = "error";   jQuery.handleError(s, xml, status, e);  }  // The request was completed  if( s.global )   jQuery.event.trigger( "ajaxComplete", [xml, s] );  // Handle the global AJAX counter  if ( s.global && ! --jQuery.active )   jQuery.event.trigger( "ajaxStop" );  // Process result  if ( s.complete )   s.complete(xml, status);  jQuery(io).unbind()  setTimeout(function() {     try {      jQuery(io).remove();      jQuery(form).remove();     } catch(e) {      jQuery.handleError(s, xml, null, e);     }     }, 100)  xml = null  } } // Timeout checker if ( s.timeout > 0 )  {  setTimeout(function(){  // Check to see if the request is still happening  if( !requestDone ) uploadCallback( "timeout" );  }, s.timeout); } try  {  var form = jQuery('#' + formId);  jQuery(form).attr('action', s.url);  jQuery(form).attr('method', 'POST');  jQuery(form).attr('target', frameId);  if(form.encoding) {  jQuery(form).attr('encoding', 'multipart/form-data');  } else {  jQuery(form).attr('enctype', 'multipart/form-data');  }    jQuery(form).submit(); } catch(e) {  jQuery.handleError(s, xml, null, e); } jQuery('#' + frameId).load(uploadCallback); return {abort: function () {}};  }, uploadHttpData: function( r, type ) { var data = !type; data = type == "xml" || data ? r.responseXML : r.responseText; // If the type is "script", eval it in global context if ( type == "script" )  jQuery.globalEval( data ); // Get the JavaScript object, if JSON is used. if ( type == "json" )  eval( "data = " + data ); // evaluate scripts within html if ( type == "html" )  jQuery("<div>").html(data).evalScripts(); return data; }})