摘抄--使用cos实现多个文件上传详解

在开发中常常需要上传文件，上传文件的方式有很多种，这里有一个cos实现的例子。

首先是要拷贝cos.jar包拷贝到WEB-INF/lib目录下，然后才进行编码。

创建一个可以进行自动重命名的Java文件FileRenameUtil.java：

package org.ml.drp.util;
import java.io.File;
import java.util.Date;
import com.oreilly.servlet.multipart.FileRenamePolicy;
/**
* 文件重命名
* @author MuLing
*
*/
public class FileRenameUtil implements FileRenamePolicy {
public File rename(File file) {
String body = "";
String ext = "";
Date date = new Date();
int pot = file.getName().lastIndexOf(".");//取得文件名和后缀分割点
if (pot != -1) {//说明后缀存在
body = date.getTime() + "";//采用时间的形式命名
ext = file.getName().substring(pot);//截取后缀名
} else {
body = (new Date()).getTime() + "";
ext = "";
}
String newName = body + ext;
file = new File(file.getParent(), newName);//对文件进行重命名
return file;
}
}

然后创建一个实现上传功能的servlet，为了方便查看上传情况，所以加入了一些输出语句。

FileUploadServlet.java

package org.ml.servlet;
import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.oreilly.servlet.MultipartRequest;
/**
* 能够进行文件上传的servlet类
* @author MuLing
*
*/
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public UploadServlet() {
super();
}
public void destroy() {
super.destroy();
}
@SuppressWarnings("unchecked")
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 存绝对路径
// String filePath = "C://upload";
// 存相对路径
String filePath = getServletContext().getRealPath("/") + "upload";
System.out.println(filePath);//输出存放上传文件所到的路径
File uploadPath = new File(filePath);
// 检查文件夹是否存在不存在创建一个
if (!uploadPath.exists()) {
uploadPath.mkdir();
}
// 文件最大容量 3M
int fileMaxSize = 3 * 1024 * 1024;
// 存放文件描述
@SuppressWarnings("unused")
String[] fileDiscription = { null, null };
// 文件名
String fileName = null;
// 上传文件数
int fileCount = 0;
// 重命名策略
RandomFileRenamePolicy rfrp = new RandomFileRenamePolicy();
// 上传文件
MultipartRequest mulit = new MultipartRequest(request, filePath,
fileMaxSize, "UTF-8", rfrp);//取得上传文件
String userName = mulit.getParameter("userName");
System.out.println(userName);
Enumeration filesname = mulit.getFileNames();//取得上传的所有文件(相当于标识)
while (filesname.hasMoreElements()) {
String name = (String) filesname.nextElement();//标识
System.out.println(name);
fileName = mulit.getFilesystemName(name); //取得文件名
String contentType = mulit.getContentType(name);//工具标识取得的文件类型
if (fileName != null) {
fileCount++;
}
System.out.println("文件名：" + fileName);
System.out.println("文件类型： " + contentType);
}
System.out.println("共上传" + fileCount + "个文件！");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
public void init() throws ServletException {
}
}

在web.xml文件中的配置servlet如下:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>UploadServlet</servlet-name>
<servlet-class>org.ml.servlet.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/UploadServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

上传页面代码如下：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<form enctype="multipart/form-data" method = "post" action = "UploadServlet">
<input type="text" name="userName" />
<p>上传文件1:<input type = "file" name = "File1" size = "20" maxlength = "20"><br></p>
<p>上传文件2:<input type = "file" name = "File2" size = "20" maxlength = "20"><br></p>
<p>上传文件3:<input type = "file" name = "File3" size = "20" maxlength = "20"><br></p>
<p>上传文件4:<input type = "file" name = "File4" size = "20" maxlength = "20"><br></p>
<input type = "submit" value = "上传">
</form>
</body>
</html>

注明：本代码是摘抄代码，所有权归 cselmu9 所有！

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摘抄--使用cos实现多个文件上传详解

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