apache commons fileupload 组件上传文件

package com.sf.novatar.plf.controller;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
* 上传
* @author sfit1512
*
*/
@Controller
@RequestMapping("/upload")
public class UploadController {


@RequestMapping(value = "/upload", method = RequestMethod.POST)
public void upload(HttpServletRequest request,HttpServletResponse response,HttpSession session){
//String transactionImportTemp = (String) request.getSession().getServletContext().getAttribute(Constants.TRANSACTION_IMPORT_TEMP); 
//String transactionImportTemp =request.getServletContext().getContextPath();
String transactionImportTemp = request.getSession().getServletContext().getRealPath("/pc-rs/novatar.frameimpl/scripts/static/upload");
       
//String transactionImportTemp ="E:\\upload";
// 设置上传文件最大为 3M 
        final long MAX_SIZE = 5 * 1024 * 1024; 
        // 允许上传的文件格式的列表 final 
        String[] allowedExt = new String[] { "xlsx" }; 
 
        response.setContentType("text/html"); // 设置字符编码为UTF-8, 这样支持汉字显示 
        response.setCharacterEncoding("UTF-8"); 
 
        // 实例化一个硬盘文件工厂,用来配置上传组件 
        DiskFileItemFactory dfif = new DiskFileItemFactory(); 
        // 设置上传文件时用于临时存放文件的内存大小,这里是4K.多于的部分将临时存在硬盘 
        dfif.setSizeThreshold(4096); // 设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录 
        File tmpFile = new File(transactionImportTemp); 
        if (!tmpFile.exists()) { 
            tmpFile.mkdirs(); 
        } 
        dfif.setRepository(tmpFile); 
 
        // 用以上工厂实例化上传组件 
        ServletFileUpload sfu = new ServletFileUpload(dfif); 
        // 设置最大上传尺寸 
        sfu.setSizeMax(MAX_SIZE); 
 
        PrintWriter out=null;
try {
out = response.getWriter();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} 
        // 从request得到 所有 上传域的列表 
        List fileList = null; 
        try { 
            fileList = sfu.parseRequest(request); 
        } catch (FileUploadException e) { 
            // 处理文件尺寸过大异常 
            e.printStackTrace(); 
            if (e instanceof SizeLimitExceededException) { 
                out.println("文件尺寸超过规定大小:" + MAX_SIZE + "字节<p />"); 
                out.println("<a href=\"upload.html\" target=\"_top\">返回</a>"); // 
                e.printStackTrace(); 
                return; 
            } 
        } 
 
        // 没有文件上传 
        if (fileList == null || fileList.size() == 0) { 
            out.println("请选择上传文件<p />"); 
            out.println("<a href=\"upload.html\" target=\"_top\">返回</a>"); //  
            return; 
        } 
 
        // 得到所有上传的文件 
        Iterator fileItr = fileList.iterator(); // 循环处理所有文件 
        while (fileItr.hasNext()) { 
            FileItem fileItem = null; 
            String path = null; 
            long size = 0; 
            // 得到当前文件 
            fileItem = (FileItem) fileItr.next(); 
            // 忽略简单form字段而不是上传域的文件域(<input type="text" />等) 
            if (fileItem == null || fileItem.isFormField()) { 
                continue; // 得到文件的完整路径 
            } 
            path = fileItem.getName(); 
            // 得到文件的大小 
            size = fileItem.getSize(); 
            if ("".equals(path) || size == 0) { 
                out.println("请选择上传文件<p />"); 
                out.println("<a href=\"upload.html\" target=\"_top\">返回</a>"); // return; 
            } 
 
            // 得到去除路径的文件名 
            String t_name = path.substring(path.lastIndexOf("\\") + 1); 
            // 得到文件的扩展名(无扩展名时将得到全名) 
            String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1); 
            // 拒绝接受规定文件格式之外的文件类型 
            int allowFlag = 0; 
            int allowedExtCount = allowedExt.length; 
            for (; allowFlag < allowedExtCount; allowFlag++) { 
                if (allowedExt[allowFlag].equals(t_ext)) { 
                    break; 
                } 
            } 
            if (allowFlag == allowedExtCount) { 
                out.println("请上传以下类型的文件<p />"); 
                for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++) { 
                    out.println("*." + allowedExt[allowFlag] 
                            + "&nbsp;&nbsp;&nbsp;"); 
                    out 
                            .println("<p /><a href=\"upload.html\" target=\"_top\">返回</a>"); // return; 
                } 
            } 
 
            // long now = System.currentTimeMillis(); 
            // 根据系统时间生成上传后保存的文件名 
            // String prefix = String.valueOf(now); 
            // 保存的最终文件完整路径,保存在web根目录下的ImagesUploaded目录下 
            // String u_name = transactionImportTemp + prefix + "." + t_ext; 
            try { // 保存文件 
                fileItem.write(new File(t_name)); 
                out.println("文件上传成功。已保存为：" + t_name + "。"); 
            } catch (Exception e) { 
                e.printStackTrace(); 
            } 
        } 
}
}