用smartUpload上传下载文件-优快云博客

本文链接：https://blog.youkuaiyun.com/u010002783/article/details/11264653

我的代码:

【Up.jsp】

<%@ page language="java"contentType="text/html"

pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTDHTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert titlehere</title>

</head>

<body>

</form>

<br/>

</body>

</html>

【upload.Java/Servlet】

package cn.up;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Date;

import java.util.UUID;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.jspsmart.upload.File;

import com.jspsmart.upload.Files;

import com.jspsmart.upload.SmartUpload;

import com.jspsmart.upload.SmartUploadException;

public class upload extends HttpServlet {

SmartUpload su ;

protected void doGet(HttpServletRequest request, HttpServletResponseresponse) throws ServletException, IOException {

request.setCharacterEncoding("UTF-8");

int method=Integer.parseInt(request.getParameter("method"));

su= new SmartUpload();

su.initialize(this.getServletConfig(), request, response);//初始化，此项必须

if(method==1){

upload(request, response);

}else if(method==2){

download(request, response);

}else{

//出错了

}

private void download(HttpServletRequest request,

HttpServletResponse response) {

//设定ContentDisposition为null以禁止浏览器自动打开文件

//response.setCharacterEncoding("UTF-8");

su.setContentDisposition(null);

String filepath="/manage/cover/";

try {

//获得请求参数

String down=request.getParameter("down");//与下面取值比较一下，与中文传值的区别

String fileName = new String(request.getParameter("fileName").getBytes("ISO-8859-1"),"utf-8");

System.out.println(fileName);

//得到文件在服务器中的路径

filepath=filepath+fileName;

//判断文件名是否有中文

if(down.equals("en")){//此处也可以进行正则表达式，判断提交的文件名是否由字母和数字组成。从而选择不同的下载处理方式

System.out.println("下载2：");

su.downloadFile(filepath);

}else{

byte[] b=fileName.getBytes();

char[]c=new char[b.length];

for(int x=0;x<b.length;x++)c[x]=(char)(b[x]&0x00FF);

fileName=new String(c);

su.downloadFile(filepath,"image/jpeg",fileName);

}

} catch (Exception e) {

e.printStackTrace();

}

private void upload(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {

Integer maxID = 432;

String result = "上传的照片格式和大小有问题,上传照片失败!";

String type = null;

String imageType[] = { "JPG", "jpg", "gif", "bmp", "BMP" };

String filedir = "/manage/cover/";

long maxsize = 2 * 1024 * 1024; // 设置每个上传文件的大小，为2MB

try {

su.setMaxFileSize(maxsize); // 限制上传文件的大小

su.upload(); // 上传文件

Files files = su.getFiles(); // 获取所有的上传文件

for (int i = 0; i < files.getCount(); i++) { // 逐个获取上传的文件

File singlefile = files.getFile(i);

type = singlefile.getFileExt();

System.out.println("提交成功2：");

for (int ii = 0; ii < imageType.length; ii++) {

if (imageType[ii].equals(type)) {

if (!singlefile.isMissing()) { // 如果选择了文件

Date time=new Date();

String timename=UUID.randomUUID().toString();

System.out.println(timename);

filedir = filedir + timename + "."

+ singlefile.getFileExt();

singlefile.saveAs(filedir, File.SAVEAS_VIRTUAL);

result = "上传照片成功!";

System.out.println(result);

}

} catch (Exception e) {

e.printStackTrace();

}

//request.getRequestDispatcher("").forward(request,response);

}

protected void doPost(HttpServletRequest request, HttpServletResponseresponse) throws ServletException, IOException {

doGet( request, response);

}

刚开始，jsp页面提交数据出现Files' name is invalid or does not exist (1205)错误，百度后解决了：

设置form中的属性enctype 为"multipart/form-data"

如：<formaction="/company/servlet/AddNewsManage" method="post" enctype="multipart/form-data"name="form1" onSubmit="return isNoNull()">

表单中enctype="multipart/form-data "的意思，是设置表单的MIME编码。默认情况，这个编码格式是application/x-www-form-urlencoded，不能用于文件上传；只有使用了multipart/form-data ，才能完整的传递文件数据，进行下面的操作.
enctype="multipart/form-data"是上传二进制数据; form里面的input的值以2进制的方式传过去。
form里面的input的值以2进制的方式传过去，所以request就得不到值了。也就是说加了这段代码,用request就会传递不成功,取表单值加入数据库时，用到下面的：

SmartUploadsu = new SmartUpload();//新建一个SmartUpload对象

su.getRequest().getParameterValues();取数组值

su.getRequest().getParameter( );取单个参数单个值