ajax上传文件（ajax+Struts1 & ajax+servlet+上传进度条）

一、Struts1 ajax上传文件
input框

ajax请求(注意需要使用支持FormData对象的jquery版本)

FormData 对象的在jquery中使用
1.创建：var formData = new formData();

2.添加键值对：formData.append('key','value');
  formData.append("formFile",$('#fileId')[0].files[0]);

3.发送数据：
	$.ajax({
		url:"<%=request.getContextPath()%>/impDataAction.do?type=uploadFile",
		type: "POST",
		data: formData,
		processData : false, // 告诉jQuery不要去处理发送的数据(必须设置)
		contentType : false, // 告诉jQuery不要去设置Content-Type请求头（必须设置）
		success: function(data) {
		    alert("ok");
		},
		error: function(request) {
			alert("Connection error");
		}
	});
}

Struts配置：

action配置，重点在于impDataForm与ImpDataAction

java代码：

if(StringUtils.equals(getParameter("type", request), "uploadFile")){
        	try {
        		FormFile formFile = impDataForm.getFormFile();
        		InputStream in = formFile.getInputStream();
        		FileOutputStream out = new FileOutputStream("D:/Users/uniz/Desktop/test/"+formFile.getFileName());
        		byte[] buf = new byte[1024];
        		int len;
        		while ((len = in.read(buf)) != -1) {
        		   out.write(buf, 0, len);
        		}
        		in.close();
        		out.close();
        	} catch (Exception e) {
        	}
        	return WebUtil.NULLActionForward;
        }

二、Ajax + Servlet + 上传进度条
需要jar包

	
	    commons-fileupload
	    commons-fileupload
	    1.3.3
	
	
	    commons-io
	    commons-io
	    2.6
	

jsp&ajax&上传进度条

<%@ page contentType="text/html;charset=UTF-8"%>
<%@ page language="java"%>





<%@ include file="/app/common/head.jsp"%>





    


	

	 选择一个文件:

    

    

    

    

    
	

servlet

package com.study.file;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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.collections.CollectionUtils;
import org.apache.commons.collections.MapUtils;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.servlet.ServletRequestContext;
import org.apache.commons.lang.StringUtils;

import com.study.json.JSONUtils;
import com.study.json.ReponseJSONBuilder;
import com.study.util.WebUtils;

/**
 * 特别注意，上传文件遇到异常时，浏览器端接收不到异常信息。
 * 原因是上传文件时浏览器请求持续时间长(文件未上传完)，发生异常后，服务器虽然立即捕获异常并响应给浏览器，
 * 但是浏览器仍然在发送上传请求，接收不到异常信息。
 * @author uniz
 */
@WebServlet("/UploadServlet")
public class UploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
     
    // 上传文件存储目录
    private static final String UPLOAD_DIRECTORY = "uploadDir";
 
    // 上传配置
    private static final int MEMORY_THRESHOLD   = 1024 * 1024 * 300*3;  // 300MB
    private static final int MAX_FILE_SIZE      = 1024 * 1024 * 400*3; // 400MB
    private static final int MAX_REQUEST_SIZE   = 1024 * 1024 * 500*3; // 500MB
 
    /**
     * 上传数据及保存文件
     */
    @SuppressWarnings("rawtypes")
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
    	if(isAjax(request)) {
    		try {
    			Map result = uploadHander(request);
				WebUtils.writeJson(response, ReponseJSONBuilder.buildSuccessMsg(JSONUtils.toJSONString(result)));
			} catch (Exception e) {
				e.printStackTrace();
				WebUtils.writeJson(response, ReponseJSONBuilder.buildErrorMsg(e));
			}
			return ;
    	}else {
    		Map result = uploadHander(request);
    		request.setAttribute("uploadFlag", MapUtils.getBooleanValue(result, "uploadFlag"));
    		request.setAttribute("message", MapUtils.getString(result, "uploadMsg")
    				+ " uploadFiles = " + MapUtils.getString(result, "uploadFiles") + "");
    		
    		request.getRequestDispatcher("/uploadfile/message.jsp").forward(request, response);
    	}
    }

	private void checkUploadFile(HttpServletRequest request) throws Exception {
		ServletRequestContext ctx = new ServletRequestContext(request);
        long requestSize = ctx.contentLength();
        if(requestSize > MAX_REQUEST_SIZE) {
        	throw new Exception("上传文件大小超过最大允许值！");
        }
        
 		if (!ServletFileUpload.isMultipartContent(request)) {
 			throw new Exception("只能 multipart/form-data 类型数据");
 		}
	}

	private boolean isAjax(HttpServletRequest req) {
		boolean isAjaxRequest = false;  
        if("XMLHttpRequest".equalsIgnoreCase(req.getHeader("x-requested-with"))){  
            isAjaxRequest = true;  
        }  
		return isAjaxRequest;
	}

	@SuppressWarnings({ "unchecked", "rawtypes" })
	private Map uploadHander(HttpServletRequest request) {
		List