JFinal中怎么使用ajaxfileupload实现图片上传功能

今天就跟大家聊聊有关JFinal中怎么使用ajaxfileupload实现图片上传功能，可能很多人都不太了解，为了让大家更加了解，小编给大家总结了以下内容，希望大家根据这篇文章可以有所收获。

1.前端jsp页面核心代码

<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>"  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"  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");   }  } });}

2.后台核心代码

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();}

附：ajaxfileupload.js代码

jQuery.extend({ createUploadIframe: function(id, uri) {  //create frame  var frameId = 'jUploadFrame' + id;  var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" ';  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("<p>").html(data).evalScripts();  return data; }})

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