使用ServletFileUpload实现上传

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commons-io下载地址：http://commons.apache.org/io/download_io.cgi

common-fileupload组件是apache的一个开源项目之一，可以从http://jakarta.apache.org/commons/fileupload/下载

<%@ 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></head><script type="text/javascript">function sc(){sub.submit();}</script><body><form action="/tests/servlet/inputTestServlet" id="sub" method="POST" enctype="multipart/form-data"><input type="file" name="file" id="file" /> <input type="button" name="inp" id="inp" value="上传" onclick="sc();"></form></body></html>

package com.input;import java.io.File;import java.io.IOException;import java.io.PrintWriter;import java.util.Iterator;import javax.servlet.ServletException;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.FileItemFactory;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;public class InputTestServlet extends HttpServlet{public InputTestServlet() {super();}public void destroy() {super.destroy();}public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //判断提交过来的表单是否为文件上传菜单         boolean isMultipart= ServletFileUpload.isMultipartContent(request);        if(isMultipart){            //构造一个文件上传处理对象            FileItemFactory factory = new DiskFileItemFactory();            ServletFileUpload upload = new ServletFileUpload(factory);            upload.setHeaderEncoding("UTF-8");//解决http报头乱码，即中文文件名乱码            Iterator items;            try{                //解析表单中提交的所有文件内容                items=upload.parseRequest(request).iterator();                while(items.hasNext()){                    FileItem item = (FileItem) items.next();                    if(!item.isFormField()){                        //取出上传文件的文件名称                        String name = item.getName();                        //取得上传文件以后的存储路径                        String fileName=name.substring(name.lastIndexOf('\\')+1,name.length());                        //上传文件以后的存储路径                        String path= request.getSession().getServletContext().getRealPath("/")+fileName;                                                //上传文件                        File uploaderFile = new File(path);                        item.getString("UTF-8"); //解决表单输入输乱码。                        item.write(uploaderFile);                        //打印上传成功信息                        response.setContentType("text/html");                        response.setCharacterEncoding("UTF-8");                        PrintWriter out = response.getWriter();                                                out.print("<font size='2'>上传文件为:"+name+"<br>保存的地址为"+path+ "</font>");                    }                }            }catch(Exception e){                e.printStackTrace();            }        }}public void init() throws ServletException {}}

最近项目中遇到要提交文件并且提交form中的诸如<input type=text id="height" name="height" value="">之类的参数，一开始一直遇到怎么也获取不到值的情况，比如用request.getAttribute("height")之类的，后来查了文档才知道不能这么用的。需要用循环fileList才可以取到form中提交的属性，以下是代码

public void doPost(HttpServletRequest request, HttpServletResponse response)              throws ServletException, IOException {          final long MAX_SIZE = 3 * 1024 * 1024;// 设置上传文件最大为 3M          // 允许上传的文件格式的列表          final String[] allowedExt = new String[] { "jpg", "jpeg", "gif","png" };                            response.setContentType("text/html");          // 设置字符编码为UTF-8, 这样支持汉字显示          // response.setCharacterEncoding("GBK");            // 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload          DiskFileItemFactory dfif = new DiskFileItemFactory();          dfif.setSizeThreshold(4096);// 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.setRepository(new File(request.getRealPath("/")                  + "ImagesUploadTemp"));// 设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录            // 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 = response.getWriter();          // 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              if (e instanceof SizeLimitExceededException) {                  out.print("<script>alert('文件尺寸超过规定大小:" + MAX_SIZE                          + "字节');history.back();</script>");                  return;              }              e.printStackTrace();          }          // 没有文件上传          if (fileList == null || fileList.size() == 0) {              out.print("<script>alert('请选择上传文件!');history.back();</script>");              return;          }          HashMap<String, String> paramMap = new HashMap<String, String>();          // 得到所有上传的文件          Iterator fileItr = fileList.iterator();          // 循环处理所有文件          FileItem fileUp= null;          String path = null;          while (fileItr.hasNext()) {              FileItem fileItem = 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()) {                  String formname=fileItem.getFieldName();//获取form中的名字                  String formcontent=fileItem.getString();                  formname=new String(formname.getBytes(),"GBK");                  formcontent=new String(formcontent.getBytes(),"GBK");                  paramMap.put(formname, formcontent);              }              else{              //得到放文件的item              fileUp= fileItem;              // 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.print("<script>alert('请选择上传文件!');history.back();</script>");                  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) {              StringBuffer sb = new StringBuffer();              for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++)                  sb.append("*." + allowedExt[allowFlag]);              out.println("<script>alert('请上传以下类型的文件" + sb.toString()                      + "');history.back();</script>");              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 = request.getRealPath("/") + "ImagesUploaded/"                  + prefix + "." + t_ext;          // 相对项目路径          String file_url = request.getContextPath() + "/"                  + "ImagesUploaded/" + prefix + "." + t_ext;          try {              // 保存文件              fileUp.write(new File(u_name));              out.println("<script  type='text/javascript'>parent.KE.plugin[\"image\"].insert('" +paramMap.get("id")                      + "', '" + file_url + "','" +paramMap.get("imgWidth")  + "','"                      +paramMap.get("imgHeight")  + "','" +paramMap.get("imgBorder")  + "','" +paramMap.get("imgTitle")                       + "')</script>");                        } catch (Exception e) {              e.printStackTrace();          }

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