jsp中使用jquery的ajaxfileupload插件怎么实现异步上传

Answer 1

ajaxfileupload实现异步上传的完整例子：
JSP页面中引入的script代码：
<script>
function ajaxFileUpload()
{
$("#loading").ajaxStart(function(){
$(this).show();
})//开始上传文件时显示一个图片
.ajaxComplete(function(){
$(this).hide();
});//文件上传完成将图片隐藏起来

$.ajaxFileUpload({
url:'AjaxImageUploadAction.action',//用于文件上传的服务器端请求地址
secureuri:false,//一般设置为false
fileElementId:'imgfile',//文件上传空间的id属性 <input type="file" id="imgfile" name="file" />
dataType: 'json',//返回值类型 一般设置为json
success: function (data, status) //服务器成功响应处理函数
{
alert(data.message);//从服务器返回的json中取出message中的数据,其中message为在struts2中定义的成员变量

if(typeof(data.error) != 'undefined')
{
if(data.error != '')
{
alert(data.error);
}else
{
alert(data.message);
}
}
},
error: function (data, status, e)//服务器响应失败处理函数
{
alert(e);
}
}
)

return false;
}
</script>
struts.xml配置文件中的配置方法：
<struts>
<package name="struts2" extends="json-default">
<action name="AjaxImageUploadAction" class="com.test.action.ImageUploadAction">
<result type="json" name="success">
<param name="contentType">text/html</param>
</result>
<result type="json" name="error">
<param name="contentType">text/html</param>
</result>
</action>
</package>
</struts>
上传处理的Action ImageUploadAction.action
package com.test.action;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Arrays;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
@SuppressWarnings("serial")
public class ImageUploadAction extends ActionSupport {

private File imgfile;
private String imgfileFileName;
private String imgfileFileContentType;
private String message = "你已成功上传文件";
public File getImgfile() {
return imgfile;
}
public void setImgfile(File imgfile) {
this.imgfile = imgfile;
}
public String getImgfileFileName() {
return imgfileFileName;
}
public void setImgfileFileName(String imgfileFileName) {
this.imgfileFileName = imgfileFileName;
}
public String getImgfileFileContentType() {
return imgfileFileContentType;
}
public void setImgfileFileContentType(String imgfileFileContentType) {
this.imgfileFileContentType = imgfileFileContentType;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}

@SuppressWarnings("deprecation")
public String execute() throws Exception {

String path = ServletActionContext.getRequest().getRealPath("/upload/mri_img_upload");
String[] imgTypes = new String[] { "gif", "jpg", "jpeg", "png","bmp" };
try {
File f = this.getImgfile();

String fileExt = this.getImgfileFileName().substring(this.getImgfileFileName().lastIndexOf(".") + 1).toLowerCase();
/*
if(this.getImgfileFileName().endsWith(".exe")){
message="上传的文件格式不允许!!!";
return ERROR;
}*/
/**
* 检测上传文件的扩展名是否合法
* */
if (!Arrays.<String> asList(imgTypes).contains(fileExt)) {
message="只能上传 gif,jpg,jpeg,png,bmp等格式的文件!";
return ERROR;
}

FileInputStream inputStream = new FileInputStream(f);
FileOutputStream outputStream = new FileOutputStream(path + "/"+ this.getImgfileFileName());
byte[] buf = new byte[1024];
int length = 0;
while ((length = inputStream.read(buf)) != -1) {
outputStream.write(buf, 0, length);
}
inputStream.close();
outputStream.flush();
} catch (Exception e) {
e.printStackTrace();
message = "文件上传失败了!!!!";
}
return SUCCESS;
}
}

Answer 2

<script type=text/javascript src=js/jquery.js</script
<script type=text/javascript src=js/ajaxfileupload.js</script
<!-- 执行上传文件操作的函数 --
<script type=text/javascript
function ajaxFileUpload(){
$.ajaxFileUpload({url:'update.do?method=uploader', //需要链接到服务器地址
secureuri:false,
fileElementId:'houseMaps', //文件选择框的id属性
dataType: 'xml', //服务器返回的格式，可以是json
success: function (data, status) //相当于java中try语句块的用法{$('#result').html('添加成功');},
error: function (data, status, e) //相当于java中catch语句块的用法{$('#result').html('添加失败');}});}</script</head<body<form method=post action=update.do?method=uploader enctype=multipart/form-data
<input type=file id=houseMaps name=houseMaps/
<input type=button value=提交 onclick=ajaxFileUpload()/</form<div id=result</div</body</html服务器代码：
public class UpdateAction extends DispatchAction {
public ActionForward uploader(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
UpFormForm upFormForm = (UpFormForm) form;
FormFile ff = upFormForm.getHouseMaps();try {InputStream is = ff.getInputStream();
File file = new File(D:/ + ff.getFileName()); //指定文件存储的路径和文件名
OutputStream os = new FileOutputStream(file);
byte[] b = new byte[1024];
int len = 0;
while((len = is.read(b)) != -1){
os.write(b, 0, len);}os.close();
is.close();
} catch (Exception e) {