(1) Java Servlet 实现
1.上传
1) 前端页面写法
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="com.test.action.FileBean"%>
<%@page import="com.test.action.DB"%>
<%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%
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>
<base href="<%=basePath%>">
<title>My JSP 'upload.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<form action="/abc/app1/file" method="post" enctype="multipart/form-data">
选择文件1：<input type="file" name="sourceFile" style="width: 70" value="浏览">
<br/>
选择文件2：<input type="file" name="sourceFile" style="width: 70" value="浏览">
<br/>
选择文件3：<input type="file" name="sourceFile" style="width: 70" value="浏览">
<br/>
<input type="submit" value="上传" style="width: 50">
</form>
<div>
<table>
<tr>
<td style="width: 82%">文件名称</td><td>下载选项</td>
</tr>
</table>
<%!private List<FileBean> getFiles(){
DB db=new DB();
List<FileBean> al = db.fileBeans();
return al;} %>
<table>
<%
List<FileBean> al = getFiles();
for(int i = 0; i < al.size(); i++){
%><tr><td style="width: 90%">
<span style="width: 30"><%=al.get(i).getName()%></span></td>
<td> <a href="/abc/app1/download?name=<%=al.get(i).getName()%>">下载</a><td></tr>
<% }%>
</table>
</div>
</body>
</html>
2) 后台servlet (FileUtils.copyFile(sourceFile[i], newFile)需要包commons-fileupload-1.2.1.jar、commons-io-1.3.2.jar.这两个文件可以从http://commons.apache.org/下载)
package com.test.action;
import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
public class FileAction {
private String dol;
private File[] sourceFile;
private String[] sourceFileFileName;
public String getDol() {
return dol;
}
public void setDol(String dol) {
this.dol = dol;
}
public File[] getSourceFile() {
return sourceFile;
}
public void setSourceFile(File[] sourceFile) {
this.sourceFile = sourceFile;
}
public String[] getSourceFileFileName() {
return sourceFileFileName;
}
public void setSourceFileFileName(String[] sourceFileFileName) {
this.sourceFileFileName = sourceFileFileName;
}
public String execute() {
System.out.println("shangchuan...");
String path = ServletActionContext.getServletContext().getRealPath(
"/imgs");
path += File.separator;
try {
for (int i = 0; i < sourceFile.length; i++) {
File newFile = new File(path + this.sourceFileFileName[i]);
DB db = new DB(newFile.toString());
if(db.addFile()){
System.out.println("true");
// byte[] b=new byte[1222];
// InputStream in=new FileInputStream(path);
// OutputStream out=new FileOutputStream(path);
// while(in.read(b)>0){
// out.write(b);
// }
FileUtils.copyFile(sourceFile[i], newFile);
}
if(!db.addFile()){
System.out.println("false");
this.dol="0";
}
}
} catch (IOException e) {
e.printStackTrace();
}
return "upload";
}
}
2.下载
1) 前端页面写法(只要有链接到后台servlet就可以,如上↑↑)
2) 后台servlet
package com.servlet;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
/**
* 实现java的下载功能,先读取资源流,然后再利用response.getOutputStream()输出,此类是servlet;
* @author Administrator
*
*/
public class FileDownServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=GBK";
// Initialize global variables
public void init() throws ServletException {
}
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
System.out.println("service");
doGet(req,resp);
}
// Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
// 得到下载文件的名字
// String filename=request.getParameter("filename");
// 解决中文乱码问题
// String filename=new
// String(request.getParameter("filename").getBytes("iso-8859-1"),"gbk");
String filename = "rss.xml";
// 创建file对象
File file = new File("F://" + filename);
// 设置response的编码方式
response.setContentType("application/x-msdownload");
// 写明要下载的文件的大小
response.setContentLength((int) file.length());
// 设置附加文件名
// response.setHeader("Content-Disposition","attachment;filename="+filename);
// 解决中文乱码
response.setHeader("Content-Disposition", "attachment;filename="
+ new String(filename.getBytes("gbk"), "iso-8859-1"));
// 读出文件到i/o流
FileInputStream fis = new FileInputStream(file);
BufferedInputStream buff = new BufferedInputStream(fis);
byte[] b = new byte[1024];// 相当于我们的缓存
long k = 0;// 该值用于计算当前实际下载了多少字节
// 从response对象中得到输出流,准备下载
OutputStream myout = response.getOutputStream();
// 开始循环下载
while (k < file.length()) {
int j = buff.read(b, 0, 1024);
k += j;
// 将b中的数据写到客户端的内存
myout.write(b, 0, j);
}
// 将写入到客户端的内存的数据,刷新到磁盘
myout.flush();
}
// Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("doPost");
doGet(request, response);
}
// Clean up resources
public void destroy() {
}
}(2) Struts 功能实现
1.上传
1) 前端页面写法
2) 后台action(同上java的上传雷同)
2.下载
1) 前端页面写法(只要有链接到后台servlet就可以)
2) 后台action
package com.test.action;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import com.opensymphony.xwork2.ActionSupport;
public class DownloadAction extends ActionSupport{
private String name;
private String DownloadFileName;
private InputStream inputStream;
public String getDownloadFileName() {
return DownloadFileName;
}
public void setDownloadFileName(String downloadFileName) {
DownloadFileName = downloadFileName;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String execute() throws Exception {
String temp=this.name;
String tem= new String(temp.getBytes("ISO8859-1"),"utf-8");
String path="F:\\apache-tomcat-6.0.36\\webapps\\abc\\imgs\\"+tem;
String filename=tem;
inputStream = new FileInputStream(new File(path));
this.DownloadFileName=new String(filename.getBytes(),"ISO8859-1");
return SUCCESS;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
<constant name="struts.multipart.maxSize" value="104857600"></constant>
<constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="false" />
<package name="app" namespace="/app1" extends="struts-default">
<action name="download" class="com.test.action.DownloadAction">
<result name="success" type="stream">
<param name="contentType">application/octet-stream</param>
<param name="inputName">inputStream</param>
<param name="contentDisposition">attachment;filename=${DownloadFileName}</param>
<param name="bufferSize">1024</param>
</result>
</action>
</package>
</struts>
(2) 使用io的开源项目完成上传文件的功能
1. jsp写法
<%@ 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>
<body>
<form action="/web/ManageServlet" method="post" enctype="multipart/form-data">
文件：<input type="file" name="videofile"/><!-- 此处的参数名称不重要 -->
<input type="submit" value=" 提 交 "/>
</form>
</body>
</html>2. 后台servelt写法
package cn.itcast.servlet;
import java.io.File;
import java.io.IOException;
import java.util.List;
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 ManageServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String title = request.getParameter("title");
String timelength = request.getParameter("timelength");
System.out.println("视频名称："+ title);
System.out.println("时长："+ timelength);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
if(isMultipart){
try{
FileItemFactory factory = new DiskFileItemFactory();
// File filetemp = new File("d:/a");
// if(!filetemp.exists()){filetemp.mkdirs();}
// factory.setRepository(new File("d:/a")); //设置临时目录
// factory.setSizeThreshold(1024*8); //8k的缓冲区,文件大于8K则保存到临时目录
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setHeaderEncoding("UTF-8");
// upload.setFileSizeMax(1024 * 1024 * 10*2);// 设置每个文件最大为20M
// upload.setSizeMax(1024 * 1024 * 100);// 一共最多能上传100M
List<FileItem> items = upload.parseRequest(request);
String dir = request.getSession().getServletContext().getRealPath("/files");
File dirFile = new File(dir);
if(!dirFile.exists()) dirFile.mkdirs();
for(FileItem item : items){
if(item.isFormField()) {//如果文本类型参数
String name = item.getFieldName();
String value = item.getString("UTF-8");
System.out.println(name+ "="+ value);
}else{//如果文件类型参数
System.out.println(dir);
File saveFile = new File(dirFile, item.getName());
item.write(saveFile);
}
}
}catch (Exception e) {
e.printStackTrace();
}
}else{
doGet(request, response);
}
}
}
3. 所需要的包
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