JAVA應用commos-fileupload完成文件上傳與下載實例解析。本站提示廣大學習愛好者：（JAVA應用commos-fileupload完成文件上傳與下載實例解析）文章只能為提供參考，不一定能成為您想要的結果。以下是JAVA應用commos-fileupload完成文件上傳與下載實例解析正文
起首給年夜家引見一文件的上傳
實體類
import java.sql.Timestamp;
/**
*
* @Decription 文件上傳實體類
*
*/
public class Upfile {
private String id;// ID主鍵 應用uuid隨機生成
private String uuidname; // UUID稱號
private String filename;//文件稱號
private String savepath; // 保留途徑
private Timestamp uploadtime; // 上傳時光
private String description;// 文件描寫
private String username; // 用戶名
public Upfile() {
super();
}
public Upfile(String id, String uuidname, String filename, String savepath,
Timestamp uploadtime, String description, String username) {
super();
this.id = id;
this.uuidname = uuidname;
this.filename = filename;
this.savepath = savepath;
this.uploadtime = uploadtime;
this.description = description;
this.username = username;
}
public String getDescription() {
return description;
}
public String getFilename() {
return filename;
}
public String getId() {
return id;
}
public String getSavepath() {
return savepath;
}
public Timestamp getUploadtime() {
return uploadtime;
}
public String getUsername() {
return username;
}
public String getUuidname() {
return uuidname;
}
public void setDescription(String description) {
this.description = description;
}
public void setFilename(String filename) {
this.filename = filename;
}
public void setId(String id) {
this.id = id;
}
public void setSavepath(String savepath) {
this.savepath = savepath;
}
public void setUploadtime(Timestamp uploadtime) {
this.uploadtime = uploadtime;
}
public void setUsername(String username) {
this.username = username;
}
public void setUuidname(String uuidname) {
this.uuidname = uuidname;
}
}
頁面
<%@ 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>
<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>
<h1>文件上傳</h1>
<form action="${pageContext.request.contextPath }/upload" method="post" enctype="multipart/form-data">
<table>
<tr>
<td> 上傳用戶名:</td>
<td><input type="text" name="username"/></td>
</tr>
<tr>
<td> 上傳文件:</td>
<td><input type="file" name="file"/></td>
</tr>
<tr>
<td> 描寫:</td>
<td><textarea rows="5" cols="50" name="description"></textarea></td>
</tr>
<tr>
<td><input type="submit" value="上傳開端"/></td>
</tr>
</table>
</form>
<div>${msg }</div>
<a href="${pageContext.request.contextPath }/index.jsp">前往主頁</a>
</body>
</html>
Servlet
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileUploadBase.FileSizeLimitExceededException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.itheima.domain.Upfile;
import com.itheima.exception.MyException;
import com.itheima.service.UpfileService;
import com.itheima.service.impl.UpfileServiceImpl;
import com.itheima.untils.WebUntil;
public class UploadFileServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//斷定表單是否是多個部門構成的
if(!ServletFileUpload.isMultipartContent(request)){
request.setAttribute("msg", "表單個設置毛病,請檢討enctype屬性是能否設置准確");
request.getRequestDispatcher("/upload.jsp").forward(request, response);
return ;
}
//是多部門構成的就獲得並遍歷前往一個文件上傳對象,包括上傳的一切信息
try {
Upfile upfile=WebUntil.upload(request);
UpfileService upfileService=new UpfileServiceImpl();
boolean flag=upfileService.add(upfile);
if(flag){
request.setAttribute("msg", "上傳勝利");
request.getRequestDispatcher("/upload.jsp").forward(request, response);
return ;
}else{
request.setAttribute("msg", "上傳掉敗,請重試");
request.getRequestDispatcher("/upload.jsp").forward(request, response);
return ;
}
}catch (FileSizeLimitExceededException e) {
e.printStackTrace();
request.setAttribute("msg", "單個文件年夜小 ,跨越最年夜限制");
request.getRequestDispatcher("/upload.jsp").forward(request, response);
return ;
} catch (SizeLimitExceededException e) {
e.printStackTrace();
request.setAttribute("msg", "總文件年夜小 ,跨越最年夜限制");
request.getRequestDispatcher("/upload.jsp").forward(request, response);
return ;
}
}
}
對象類
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadBase;
import org.apache.commons.fileupload.FileUploadBase.FileSizeLimitExceededException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.ProgressListener;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.itheima.domain.Upfile;
import com.itheima.exception.MyException;
/**
* 文件上傳對象類
* @Decription TODO
*
*/
public class WebUntil {
/**
* 文件上傳的辦法
* @param request 要求參數傳入
* @return 前往一個Upfile對象
* @throws FileSizeLimitExceededException
* @throws SizeLimitExceededException
* @throws IOException
*/
public static Upfile upload(HttpServletRequest request) throws FileSizeLimitExceededException, SizeLimitExceededException {
Upfile upfile=new Upfile();
ArrayList<String> fileList=initList();
try {
//獲得磁盤文件對象工場
DiskFileItemFactory factory=new DiskFileItemFactory();
String tmp=request.getSession().getServletContext().getRealPath("/tmp");
System.out.println(tmp);
//初始化工場
setFactory(factory,tmp);
//獲得文件上傳解析器
ServletFileUpload upload=new ServletFileUpload(factory);
//初始化解析器
setUpload(upload);
//獲得文件列表聚集
List<FileItem> list = upload.parseRequest(request);
//遍歷
for (FileItem items : list) {
//斷定 是否是通俗表單個對象
if(items.isFormField()){
//獲得上傳表單的name
String fieldName=items.getFieldName();
//value
String fieldValue=items.getString("UTF-8");
//斷定
if("username".equals(fieldName)){
//設置
upfile.setUsername(fieldValue);
}else if("description".equals(fieldName)){
//設置屬性
upfile.setDescription(fieldValue);
}
}else{
//是文件就預備上傳
//獲得文件名
String filename=items.getName();
//處置由於閱讀器分歧而招致的 取得 的 文件名的 差別
int index=filename.lastIndexOf("\\");
if(index!=-1){
filename=filename.substring(index+1);
}
//生成隨機的文件名
String uuidname=generateFilename(filename);
//獲得上傳的文件途徑
String savepath=request.getSession().getServletContext().getRealPath("/WEB-INF/upload");
//獲得要求對象中的輸出流
InputStream in = items.getInputStream();
//將文件打散寄存在分歧的途徑,求前途徑
savepath=generateRandomDir(savepath,uuidname);
//復制文件
uploadFile(in,savepath,uuidname);
String id=UUID.randomUUID().toString();
upfile.setId(id);
upfile.setSavepath(savepath);
upfile.setUuidname(uuidname);
upfile.setFilename(filename);
//消除緩存
items.delete();
}
}
}catch ( FileUploadBase.FileSizeLimitExceededException e) {
//拋出出異常
throw e;
} catch (FileUploadBase.SizeLimitExceededException e) {
//拋出出異常
throw e;
}catch (FileUploadException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return upfile;
}
/**
* 初始化文件列表
* @return
*/
private static ArrayList<String> initList() {
ArrayList<String> list=new ArrayList<String>();
list.add(".jpg");
list.add(".rar");
list.add(".txt");
list.add(".png");
return list;
}
/**
* 復制文件
* @param in items中的輸出流
* @param savepath 保留途徑
* @param uuidname 文件名
*/
private static void uploadFile(InputStream in, String savepath,
String uuidname) {
//獲得文件
File file=new File(savepath, uuidname);
OutputStream out = null;
try {
int len=0;
byte [] buf=new byte[1024];
//獲得輸入流
out = new FileOutputStream(file);
while((len=in.read(buf))!=-1){
out.write(buf, 0, len);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 生成隨機的寄存途徑
* @param savepath 保留途徑
* @param uuidname 生成的uuid稱號
* @return
* 應用hashcode完成
*/
private static String generateRandomDir(String savepath, String uuidname) {
//轉化為hashcode
System.out.println("上傳途徑"+savepath);
System.out.println("UUIDNAME"+uuidname);
int hashcode=uuidname.hashCode();
//容器
StringBuilder sb=new StringBuilder();
while(hashcode>0){
//與上15
int tmp=hashcode&0xf;
sb.append("/");
sb.append(tmp+"");
hashcode=hashcode>>4;
}
//拼接新的途徑
String path=savepath+sb.toString();
System.out.println("path"+path);
File file=new File(path);
//斷定途徑存不存在
if(!file.exists()){
//不存在就創立
file.mkdirs();
}
//前往保留途徑
return path;
}
/**
* 生成新的文件名
* @param uuidname 隨機的ID名字
* @param filename 本來的名
* @return
*/
private static String generateFilename( String filename) {
String uuidname=UUID.randomUUID().toString();
return uuidname.replace("-", "").toString()+"_"+filename;
}
/**
* 初始化解析器
* @param upload
*/
private static void setUpload(ServletFileUpload upload) {
// 設置 字符編碼
upload.setHeaderEncoding("utf-8");
//設置文件年夜小
upload.setFileSizeMax(1024*1024*20);
//設置總文件年夜小
upload.setSizeMax(1024*1024*50);
//設置進度監聽器
upload.setProgressListener(new ProgressListener() {
public void update(long pBytesRead, long pContentLength, int pItems) {
System.out.println("曾經讀取: "+pBytesRead+",總共有: "+pContentLength+", 第"+pItems+"個");
}
});
}
/**
* 工場初始化辦法
* @param factory
* @param tmp 緩沖目次
*/
private static void setFactory(DiskFileItemFactory factory, String tmp) {
/// 設置裝備擺設初始化值緩沖區
factory.setSizeThreshold(1024*1024);
File file=new File(tmp);
//設置緩沖目次
factory.setRepository(file);
}
}
二文件下載
Servlet
public class DownupfileServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//獲得ID
String id=request.getParameter("id");
//營業層的接口
UpfileService upfileService=new UpfileServiceImpl();
//依據ID查找這個對象
Upfile upfile=upfileService.findUpfileById(id);
if(upfile==null){
return;
}
//獲得文件的真實稱號
String filename=upfile.getFilename();
//假如文件名中有中文,須要轉碼,否則就下載時沒有文件名
filename=URLEncoder.encode(filename, "utf-8");
//更悛改的稱號
String uuidname=upfile.getUuidname();
//保留途徑
String savepath=upfile.getSavepath();
File file=new File(savepath,uuidname);
//斷定文件 能否存在
if(!file.exists()){
request.setAttribute("msg", "下載 的文件過時了");
request.getRequestDispatcher("/index").forward(request, response);
return;
}
//設置文件下載呼應頭信息
response.setHeader("Content-disposition", "attachement;filename="+filename);
//應用IO流輸入
InputStream in = new FileInputStream(file);
ServletOutputStream out = response.getOutputStream();
int len=0;
byte [] buf=new byte[1024];
while((len=in.read(buf))!=-1){
out.write(buf, 0, len);
}
in.close();
}
}
數據庫
create database upload_download_exercise; use upload_download_exercise; create table upfiles( id varchar(100), //應用UUID生成 uuidname varchar(255),//uuid加上本來的文件名 filename varchar(100),//真實文件名 savepath varchar(255),//保留途徑 uploadtime timestamp,//上傳時光 description varchar(255),//描寫 username varchar(10) 上傳人 );
以上所述是小編給年夜家分享的JAVA應用commos-fileupload完成文件上傳與下載的相干內容，願望對年夜家有所贊助。
