IE9 jQuery ajax文件上传兼容问题解决。主要通过jQuery的jquery.form插件解决的IE9不支持formData的文件上传问题。<h2>1.准备</h2>
下载jQuery1.x版本（测试用v1.12.4）<br />
下载jQuery的form插件（<a href="http://plugins.jquery.com/form/" rel="external nofollow" target="_blank">下载地址</a>）<br />
本例子是通过Java后端进行测试的，后端为spring boot框架
<h2>2.后端代码</h2>
1测试的controller代码
<pre>
<code class="language-java">package com.example;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class TestController {
@GetMapping(value = { "/", "/index.html" })
public Object index() {
return new ModelAndView("index");
}
@PostMapping(value = { "/fileupload.do" }, produces = { "text/html;charset=UTF-8" })
@ResponseBody
public Object fileUpload(String name, MultipartFile file) {
try {
if (file.getBytes().length > 0) {
return "{\"message\":\"success\",\"name\":\"" + name + "\"}";
} else {
return "{\"message\":\"fail\"}";
}
} catch (Exception e) {
throw new RuntimeException("文件上传异常");
}
}
@PostMapping(value = { "/fileupload2.do" }/*, produces = { "text/html;charset=UTF-8" }*/)
public void fileUpload2(String name, MultipartFile file,HttpServletResponse response) {
try {
if (file.getBytes().length > 0) {
response.setContentType("");
response.setHeader("Content-Type", "text/html;charset=UTF-8");
response.getWriter().write("{\"message\":\"success\",\"name\":\"" + name + "\"}");
} else {
response.setHeader("Content-Type", "text/html;charset=UTF-8");
response.getWriter().write("{\"message\":\"fail\"}");
}
} catch (Exception e) {
throw new RuntimeException("文件上传异常");
}
}
}
</code></pre>
<span style="color:#e74c3c">注意:上面的第一种写法<strong>produces = { "text/html;charset=UTF-8" }</strong>必须这样写,其他写法则会出现各种问题</span>
<p> </p>
<h2>3.后端代码</h2>
1HTML页面代码
<pre>
<code class="language-html"><!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8"/>
<title>测试</title>
</head>
<body>
<form method="post" enctype="multipart/form-data" id="upload-form">
<input type="text" name="name" />
<input type="file" name="file"/>
</form>
<button type="button" id="btn-upload">上传测试</button>
<script type="text/javascript" src="/libs/jquery.min.js"></script>
<script type="text/javascript" src="/libs/jquery.form.js"></script>
<script type="text/javascript" src="/libs/index.js"></script>
</body>
</html></code></pre>
<br />
2.index.js文件代码
<pre>
<code class="language-javascript">/**
*
*/
$(function() {
$('#btn-upload').click(function(){
var options = {
url : "/fileupload.do",
success : function(data) {
var returnData = JSON.parse(data);
alert(data);
},
resetForm : true,
};
$("#upload-form").ajaxSubmit(options);
})
})</code></pre>
<h2>4jQuery form控件API</h2>
<h2>Options</h2>
<p><strong>Note:</strong> All standard <a href="http://api.jquery.com/jQuery.ajax" rel="external nofollow" target="_blank">$.ajax</a> options can be used.</p>
<h3>beforeSerialize</h3>
<p>Callback function invoked prior to form serialization. Provides an opportunity to manipulate the form before its values are retrieved. Returning <code>false</code> from the callback will prevent the form from being submitted. The callback is invoked with two arguments: the jQuery wrapped form object and the options object.</p>
<pre>
<code class="language-javascript">beforeSerialize: function($form, options) {
// return false to cancel submit
}</code></pre>
<h3>beforeSubmit</h3>
<p>Callback function invoked prior to form submission. Returning <code>false</code> from the callback will prevent the form from being submitted. The callback is invoked with three arguments: the form data in array format, the jQuery wrapped form object, and the options object.</p>
<pre>
<code class="language-javascript">beforeSubmit: function(arr, $form, options) {
// form data array is an array of objects with name and value properties
// [ { name: 'username', value: 'jresig' }, { name: 'password', value: 'secret' } ]
// return false to cancel submit
}</code></pre>
<h3>filtering</h3>
<p>Callback function invoked before processing fields. This provides a way to filter elements.</p>
<pre>
<code class="language-javascript">filtering: function(el, index) {
if ( !$(el).hasClass('ignore') ) {
return el;
}
}</code></pre>
<h3>clearForm</h3>
<p>Boolean flag indicating whether the form should be cleared if the submit is successful</p>
<h3>data</h3>
<p>An object containing extra data that should be submitted along with the form.</p>
<pre>
<code>data: { key1: 'value1', key2: 'value2' }
</code></pre>
<h3>dataType</h3>
<p>Expected data type of the response. One of: null, 'xml', 'script', or 'json'. The dataType option provides a means for specifying how the server response should be handled. This maps directly to jQuery's dataType method. The following values are supported:</p>
<ul>
<li>'xml': server response is treated as XML and the 'success' callback method, if specified, will be passed the responseXML value</li>
<li>'json': server response will be evaluted and passed to the 'success' callback, if specified</li>
<li>'script': server response is evaluated in the global context</li>
</ul>
<h3>delegation</h3>
<p>true to enable support for event delegation <em>requires jQuery v1.7+</em></p>
<pre>
<code class="language-javascript">// prepare all existing and future forms for ajax submission
$('form').ajaxForm({
delegation: true
});</code></pre>
<h3>error</h3>
<p>Callback function to be invoked upon error.</p>
<h3>forceSync</h3>
<p>Only applicable when explicity using the iframe option or when uploading files on browses that don't support XHR2. Set to <code>true</code> to remove the short delay before posting form when uploading files. The delay is used to allow the browser to render DOM updates prior to performing a native form submit. This improves usability when displaying notifications to the user, such as "Please Wait..."</p>
<h3>iframe</h3>
<p>Boolean flag indicating whether the form should <em>always</em> target the server response to an iframe instead of leveraging XHR when possible.</p>
<h3>iframeSrc</h3>
<p>String value that should be used for the iframe's src attribute when an iframe is used.</p>
<h3>iframeTarget</h3>
<p>Identifies the iframe element to be used as the response target for file uploads. By default, the plugin will create a temporary iframe element to capture the response when uploading files. This options allows you to use an existing iframe if you wish. When using this option the plugin will make no attempt at handling the response from the server.</p>
<h3>method</h3>
<p>The HTTP method to use for the request (e.g. 'POST', 'GET', 'PUT').</p>
<h3>replaceTarget</h3>
<p>Optionally used along with the the target option. Set to true if the target should be replaced or false if only the target contents should be replaced.</p>
<h3>resetForm</h3>
<p>Boolean flag indicating whether the form should be reset if the submit is successful</p>
<h3>semantic</h3>
<p>Boolean flag indicating whether data must be submitted in strict semantic order (slower). Note that the normal form serialization is done in semantic order with the exception of input elements of <code>type="image"</code>. You should only set the semantic option to true if your server has strict semantic requirements and your form contains an input element of <code>type="image"</code>.</p>
<h3>success</h3>
<p>Callback function to be invoked after the form has been submitted. If a 'success' callback function is provided it is invoked after the response has been returned from the server. It is passed the following standard jQuery arguments:</p>
<ol>
<li><code>data</code>, formatted according to the dataType parameter or the dataFilter callback function, if specified</li>
<li><code>textStatus</code>, string</li>
<li><code>jqXHR</code>, object</li>
<li><code>$form</code> jQuery object containing form element</li>
</ol>
<h3>target</h3>
<p>Identifies the element(s) in the page to be updated with the server response. This value may be specified as a jQuery selection string, a jQuery object, or a DOM element.</p>
<h3>type</h3>
<p>The HTTP method to use for the request (e.g. 'POST', 'GET', 'PUT').<br />
An alias for <code>method</code> option. Overridden by the <code>method</code> value if both are present.</p>
<h3>uploadProgress</h3>
<p>Callback function to be invoked with upload progress information (if supported by the browser). The callback is passed the following arguments:</p>
<ol>
<li>event; the browser event</li>
<li>position (integer)</li>
<li>total (integer)</li>
<li>percentComplete (integer)</li>
</ol>
<h3>url</h3>
<p>URL to which the form data will be submitted.</p>
<hr />
<h2>Utility Methods</h2>
<h3>formSerialize</h3>
<p>Serializes the form into a query string. This method will return a string in the format: <code>name1=value1&name2=value2</code></p>
<pre>
<code>var queryString = $('#myFormId').formSerialize();</code></pre>
<h3>fieldSerialize</h3>
<p>Serializes field elements into a query string. This is handy when you need to serialize only part of a form. This method will return a string in the format: <code>name1=value1&name2=value2</code></p>
<pre>
<code>var queryString = $('#myFormId .specialFields').fieldSerialize();</code></pre>
<h3>fieldValue</h3>
<p>Returns the value(s) of the element(s) in the matched set in an array. This method always returns an array. If no valid value can be determined the array will be empty, otherwise it will contain one or more values.</p>
<h3>resetForm</h3>
<p>Resets the form to its original state by invoking the form element's native DOM method.</p>
<h3>clearForm</h3>
<p>Clears the form elements. This method emptys all of the text inputs, password inputs and textarea elements, clears the selection in any select elements, and unchecks all radio and checkbox inputs. It does <em>not</em> clear hidden field values.</p>
<h3>clearFields</h3>
<p>Clears selected field elements. This is handy when you need to clear only a part of the form.</p>
<hr />
<h2>File Uploads</h2>
<p>The Form Plugin supports use of XMLHttpRequest Level 2 and <a href="https://developer.mozilla.org/en/XMLHttpRequest/FormData" rel="external nofollow" target="_blank">FormData</a> objects on browsers that support these features. As of today (March 2012) that includes Chrome, Safari, and Firefox. On these browsers (and future Opera and IE10) files uploads will occur seamlessly through the XHR object and progress updates are available as the upload proceeds. For older browsers, a fallback technology is used which involves iframes. <a href="http://malsup.com/jquery/form/#file-upload" rel="external nofollow" target="_blank">More Info</a></p>