前端处理
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<Meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<!-- 引用jquery -->
<script src="//code.jquery.com/jquery-1.11.0.min.js"></script>
<script src="//code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
<!-- 引用ajaxfileupload.js -->
<script src="../js/ajaxfileupload.js"></script>
<script type="text/javascript">
$(function(){
//点击打开文件选择器
$("#upload").on('click',function() {
$('#fileToUpload').click();
});
//选择文件之后执行上传
$('#fileToUpload').on('change',function() {
$.ajaxFileUpload({
url:'../FileUploadServlet',secureuri:false,fileElementId:'fileToUpload',//file标签的id
dataType: 'json',//返回数据的类型
data:{name:'logan'},//一同上传的数据
success: function (data,status) {
//把图片替换
var obj = jQuery.parseJSON(data);
$("#upload").attr("src","../image/"+obj.fileName);
if(typeof(data.error) != 'undefined') {
if(data.error != '') {
alert(data.error);
} else {
alert(data.msg);
}
}
},error: function (data,status,e) {
alert(e);
}
});
});
});
</script>
</head>
<body>
<!-- 点击图片，打开文件选择器，确定，上传。(这是网络上的一个图片) -->
<img id="upload" alt="" style="width: 200px; height: 200px"
src="http://d.pcs.baidu.com/thumbnail/e8119cd92364a9b2714ea0a92af15aec?fid=2399642819-250528-305026848845811&time=1405674000&sign=FDTAER-DCb740ccc5511e5e8fedcff06b081203-abo3xnZkLb7yMEPLDWiuaQI8kXM%3D&rt=sh&expires=2h&r=900585425&sharesign=unknown&size=c710_u500&quality=100">
<!-- 隐藏file标签 -->
<input id="fileToUpload" style="display: none" type="file" name="upfile"><br/>
</body>
</html>
后台处理
package com.yangshidesign.weixinface.servlet;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.alibaba.fastjson.JSONObject;
/**
* Servlet implementation class FileUploadServlet
*/
@WebServlet("/FileUploadServlet")
public class FileUploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {
response.getWriter().println("ppppppppppppppppppp");
}
protected void doPost(HttpServletRequest request,IOException {
//需要返回的fileName
String fileName = null;
//参考资料 http://commons.apache.org/proper/commons-fileupload/using.html
// Check that we have a file upload request
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
// Configure a repository (to ensure a secure temp location is used)
ServletContext servletContext = this.getServletConfig().getServletContext();
File repository = (File) servletContext.getAttribute("javax.servlet.context.tempdir");
factory.setRepository(repository);
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// Parse the request
try {
List<FileItem> items = upload.parseRequest(request);
for(FileItem item : items) {
//其他参数
String type = item.getContentType();
if(type == null) {
// System.out.println(item.getString(item.getFieldName()));
continue;
}
//文件参数
fileName = item.getName();
//设置保存文件路径
String realPath = request.getServletContext().getRealPath("/image");
File dir = new File(realPath);
File f = new File(dir,fileName);
if(f.exists()) {
f.delete();
}
f.createNewFile();
//保存
item.write(f);
}
} catch (FileUploadException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
//返回结果
JSONObject obj = new JSONObject();
obj.put("fileName",fileName);
response.getWriter().print(obj.toJSONString());
}
}
需要用到的一个js文件：（点击下载）
两个jar包：
解决方法：（参考链接：http://www.myexception.cn/ajax/727453.html）
打开ajaxfileupload.js拉到底下找到
改成：
@H_502_76@copy
