Java 夹杂文本字段的文件上传 后台实现（包括前端jquery实现的备忘）
简述：
使用了FileItem,对网页端 带有字段的Input文本 ，所以会有nameValuePair这个map的存在
以及文件上传做处理，
知识点：
1. 后台文件夹杂表单字段上传的解析，以及文件的本地保存
2. 前端JS一些常用函数，包括url解析，获取contextPath, 简单的正则解析带一层标签的文本（用于解析<pre..>JSON Str</pre>格式）
3. jquery选择器的简单试用
后台实现主要代码：
/**
* 文件上传表单处理，保存文件的路径, 同时记录表单内的值对
* @param request
* @param childPath 项目部署到服务器，存储的子路径
* @param nameValuePair 存放名字值对
* @return
*/
protected String saveUploadFile(HttpServletRequest request, final String childPath,
Map<String, String> nameValuePair){
//文件在服务器保存的路径
String path = null;
//外部访问路径
String fileSuffix = null;
String fileName = null;
//判断提交过来的表单是否为文件上传菜单
boolean isMultipart= ServletFileUpload.isMultipartContent(request);
if(isMultipart){
//构造一个文件上传处理对象
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
Iterator items;
try{
//解析表单中提交的所有文件内容
items = upload.parseRequest(request).iterator();
while(items.hasNext()){
FileItem item = (FileItem) items.next();
if(!item.isFormField()){
//取出上传文件的文件名称
String name = item.getName();
//取得上传文件以后的存储路径
fileSuffix = name.substring(name.lastIndexOf('.'), name.length());
//时间到微秒取 文件名
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmssSSS");
fileName = sdf.format(new Date());
//上传文件以后的存储路径
String saveDir = this.getServletContext().getRealPath(childPath);
if (!(new File(saveDir).isDirectory())){
new File(saveDir).mkdir();
}
path = saveDir + File.separatorChar + fileName + fileSuffix;
//上传文件
File uploaderFile = new File(path);
item.write(uploaderFile);
}else{
String name = item.getFieldName();
String value = item.getString( "UTF-8");
nameValuePair.put(name, value);
logger.info("name: " + name +"\nvalue: " + value );
}
}
}catch(Exception e){
e.printStackTrace();
return null;
}
}
//返回客户端访问的地址
String requestUrl = nameValuePair.get("contextPath") + childPath + fileName + fileSuffix;
return requestUrl;
}
前端Javascript代码部分，现只在chrome上调试，firefox上传的回调函数success还是有问题：
在编程过程中发现试用ajaxFileUpload.js文件上传库在返回的时候自带<pre。。> 标签，所以filetype: text， 对返回的文本在转JSON后显示
<script type="text/javascript">
function GetContextPath(){
var localObj = window.location;
var contextPath = localObj.pathname.split("/")[1];
var basePath = localObj.protocol+"//"+localObj.host+"/"+contextPath;
return basePath;
}
//获取URL中参数
function GetRequest() {
var url = location.search; //获取url中"?"符后的字串
var theRequest = new Object();
if (url.indexOf("?") != -1) {
var str = url.substr(1);
strs = str.split("&");
for(var i = 0; i < strs.length; i ++) {
theRequest[strs[i].split("=")[0]]=unescape(strs[i].split("=")[1]);
}
}
return theRequest;
}
function ParseTextToJsonObject(data){
var reg = /<pre.+?>(.*)<\/pre>/g;
data.match(reg);
var jsonStr = RegExp.$1;
if(jsonStr != "")
obj = jQuery.parseJSON(jsonStr);
else
obj =jQuery.pareseJSON(data);
return obj;
}
function ajaxFileUploadUnitImage() {
$.ajaxFileUpload({
url : "./building?action=UploadUnitImage" , //submit to UploadFileServlet
data: {
contextPath: GetContextPath(),
unitId: $("#unitId").val(),
imageType: $("#imageTypeSelector").val(),
label: $("#labelInput").val(),
userDescribe: $("#userDescribeInput").val()
},
secureuri : false,
fileElementId : 'fileToUpload',
dataType : 'text',
success : function(data, status) {
//转换为JSON对象
var obj = ParseTextToJsonObject(data);
UpdateColumn(obj);
},
error : function(data, status, e) {
console.info("Error");
alert("上传文件为空");
}
});
return false;
}
function DeleteUnitImage(unitImageId){
jQuery.ajax({
type:"GET",
url: "./building?action=DeleteUnitImage"
+ "&unitId=" + $('input[name="unitId"]').attr('value')
+ "&unitImageId=" + unitImageId,
dataType:"json",
global:false,
success: function(data){
UpdateColumn(data);
},
error: function(data){
alert("删除失败");
}
});
}
</script>
</head>
<body>
<h3 class="left">图片上传</h3>
</div>
<!-- upload file -->
<form name="form" method="POST" enctype="multipart/form-data">
<table class="tableForm">
<tbody>
<tr>
<td>
<input type="text" name="unitId" value=""><br/>
</td>
</tr>
<tr>
<select id="imageTypeSelector" name="imageType" >
<option value="0" selected="selected">户型图</option>
<option value="1">图2</option>
<option value="2">图3</option>
</select>
</tr>
<tr>
<td>
<label class="">二级标签: </label>
</td>
<td>
<input id="labelInput" type="text" name="label" >
</td>
</tr>
<tr>
<td>
<label class="">用户描述: </label>
</td>
<td>
<input id="userDescribeInput" type="text" name="userDescribe" >
</td>
</tr>
<tr>
<td><input id="fileToUpload" type="file" size="45"
name="fileToUpload" class="input"></td>
</tr>
</tbody>
<tfoot>
<tr>
<td><button class="button" id="buttonUpload"
onclick="return ajaxFileUploadUnitImage();">Upload</button></td>
</tr>
</tfoot>
</table>
</form>
</body>
</html>
后面是试用的AjaxFileUpload.js库，jquery用的是1.8.3
ajaxfileupload.js 需要添加handleError函数，这个函数存在于早起jquery版本，但是ajaxfileupload库还是沿用了，所以要人为地加入
jQuery.extend({
handleError: function( s, xhr, status, e ) {
// If a local callback was specified, fire it
if ( s.error ) {
s.error.call( s.context || s, xhr, status, e );
}
// Fire the global callback
if ( s.global ) {
(s.context ? jQuery(s.context) : jQuery.event).trigger( "ajaxError", [xhr, s, e] );
}
},
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;
}
})
界面简图：
