JFinal使用ajaxfileupload实现图片上传及预览

JFinal使用ajaxfileupload实现图片上传及预览

本文实例为大家分享了JFinal使用ajaxfileupload实现图片上传预览的具体代码，供大家参考，具体内容如下

1.前端jsp页面核心代码

<%=request.getContextPath() %>/media/file/${banner.img}" style="width:300px;height:100px;" id="imgsrc"/>

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 = '

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('

if(data) {

for(var i in data) {

jQuery('').appendTo(form);

}

}

var oldElement = jQuery('#' + fileElementId);

var newElement = jQuery(oldElement).clone();

jQuery(oldElement).attr('id', fileId);

jQuery(oldElemeasSVyZFBGnt).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("

return data;

}

})

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