FileUpload的简单使用

最新推荐文章于 2022-08-11 21:25:26 发布

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#import #servlet #input #jfreechart #file #table

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1.首先要在Apache网站上下载如下两个包：

将文件夹下的这两个jar引入到项目中

2.前台使用界面的编写：

<html>

<head>

<title>index.html</title>

</head>

<body>

</form>

<table border="1" width="450" cellpadding="4" cellspacing="2"

bordercolor="#9BD7FF">

<tr>

文件1：

</td>

</tr>

<tr>

文件2：

</td>

</tr>

<tr>

文件3：

</td>

</tr>

</table>

<br />

<table>

<tr>

</td>

</tr>

</table>

</form>

</body>

</html>

效果如下图所示：

3.编写sevlet : FIleUpload.java(我让其在web.xml中接收一个初始化参数，此参数是上传文件存放的位置)

package com.ycringfinger.shopping.servlet;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletConfig;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.*;

import java.util.*;

import java.util.regex.*;

import java.io.*;

import org.apache.commons.fileupload.servlet.*;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

public class FileUpload extends HttpServlet {

public void init(ServletConfig config) throws ServletException {

uploadPath = config.getInitParameter("uploadpath");

}

String uploadPath = "";

public void destroy() {

super.destroy(); // Just puts "destroy" string in log

// Put your code here

}

public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

res.setContentType("text/html; charset=GB2312");

int id = -1;

PrintWriter out = res.getWriter();

//System.out.println(req.getContentLength());

//System.out.println(req.getContentType());

DiskFileItemFactory factory = new DiskFileItemFactory();

// maximum size that will be stored in memory

factory.setSizeThreshold(4096);

// the location for saving data that is larger than getSizeThreshold()

factory.setRepository(new File("d:/"));

ServletFileUpload upload = new ServletFileUpload(factory);

// maximum size before a FileUploadException will be thrown

upload.setSizeMax(1000000);

try {

List fileItems = upload.parseRequest(req);

// assume we know there are two files. The first file is a small text file, the second is unknown and is written to a file on the server

Iterator iter = fileItems.iterator();

// 正则匹配，过滤路径取文件名

String regExp = ".+//(.+)$";

// 过滤掉的文件类型

String[] errorType = { ".exe", ".com", ".cgi", ".asp" };

Pattern p = Pattern.compile(regExp);

while (iter.hasNext()) {

FileItem item = (FileItem) iter.next();

if(item.isFormField()) {

if(item.getFieldName().equals("id")) {

id = Integer.parseInt(item.getString());

//System.out.println(id);

}

// 忽略其他不是文件域的所有表单信息

if (!item.isFormField()) {

String name = item.getName();

long size = item.getSize();

if ((name == null || name.equals("")) && size == 0) {

continue;

}

Matcher m = p.matcher(name);

boolean result = m.find();

if (result) {

for (int temp = 0; temp < errorType.length; temp++) {

if (m.group(1).endsWith(errorType[temp])) {

throw new IOException(name + ": wrong type");

}

try {

// 保存上传的文件到指定的目录

// 在下文中上传文件至数据库时，将对这里改写

item.write(new File(uploadPath + id + ".jpg"));

out.print(name + "  " + size + "<br>");

} catch (Exception e) {

out.println(e);

}

} else {

throw new IOException("fail to upload");

}

} catch (IOException e) {

out.println(e);

} catch (FileUploadException e) {

out.println(e);

}

// 保存上传的文件到指定的目录

// 在下文中上传文件至数据库时，将对这里改写

}

public void init() throws ServletException {

}

4.我的web.xml的配置（其中也包含了JFreeChart）

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.4"

xmlns="http://java.sun.com/xml/ns/j2ee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee

http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

<description>FileUpload</description>

<display-name>FileUpload</display-name>

<servlet-name>FileUpload</servlet-name>

<servlet-class>com.ycringfinger.shopping.servlet.FileUpload</servlet-class>

<init-param>

<param-name>uploadpath</param-name>

<param-value>D:/JavaWork/Shopping/WebRoot/images/product/</param-value>

</init-param>

</servlet>

<servlet-name>ProductSalesChart</servlet-name>

<servlet-class>com.ycringfinger.shopping.chart.ProductSalesChart</servlet-class>

<init-param>

<param-name>generatedpath</param-name>

<param-value>D:/JavaWork/Shopping/WebRoot/images/productsales/</param-value>

</init-param>

</servlet>

<servlet-mapping>

<servlet-name>FileUpload</servlet-name>

<url-pattern>/FileUpload</url-pattern>

</servlet-mapping>

<servlet-mapping>

<servlet-name>ProductSalesChart</servlet-name>

<url-pattern>/ProductSalesChart</url-pattern>

</servlet-mapping>

</web-app>