[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现
遍历上传目录下的所有文件显示给用户，并允许用户完成下载。
（读取某一个文件夹下的所有的文件，存到集合里面List，再存到request作用域范围中）。
一个表的相关字段：
CREATETABLE `upfile` (
`id` varchar(50) NOT NULL,
`uuidname` varchar(255) NOT NULL,
`realname` varchar(255) NOT NULL,
`savepath` varchar(255) NOT NULL,
`uptime` datetime NOT NULL,
`description` varchar(255) DEFAULT NULL,
`username` varchar(40) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULTCHARSET=utf8;
一个实体类：
publicclass UploadFile {
privateString id ;
private String uuidname ;
private String realname;
private String savepath ;
private Date uptime ;
private String description ;
private String username ;
public String getId() {
returnid;
}
publicvoid setId(String id) {
this.id = id;
}
public StringgetUuidname() {
returnuuidname;
}
publicvoid setUuidname(String uuidname) {
this.uuidname = uuidname;
}
public StringgetRealname() {
returnrealname;
}
publicvoid setRealname(String realname) {
this.realname = realname;
}
public StringgetSavepath() {
returnsavepath;
}
publicvoid setSavepath(String savepath) {
this.savepath = savepath;
}
public Date getUptime(){
returnuptime;
}
publicvoid setUptime(Date uptime) {
this.uptime = uptime;
}
public StringgetDescription() {
returndescription;
}
publicvoid setDescription(String description) {
this.description = description;
}
public StringgetUsername() {
returnusername;
}
publicvoid setUsername(String username) {
this.username = username;
}
}
一个dao接口：
public interface UploadFileDao {
publicvoid insert(UploadFile f);
public UploadFilegetUploadFile(String id);
publicList<UploadFile> getUploadFiles();
}
该接口的实现类：
publicclass UploadFileDaoImpl implements UploadFileDao{
@Override
public UploadFilegetUploadFile(String id) {
QueryRunner qr = new QueryRunner(DBManager.getDataSource());
String sql = "selectid,uuidname,realname,savepath,uptime,description,username from uploadfile where id=?";
try {
UploadFile uf = qr.query(sql,id,new BeanHandler(UploadFile.class));
return uf;
} catch(SQLException e) {
thrownew RuntimeException(e);
}
}
@Override
publicList<UploadFile> getUploadFiles() {
QueryRunner qr = new QueryRunner(DBManager.getDataSource());
String sql = "selectid,uuidname,realname,savepath,uptime,description,username from uploadfile order by uptime desc";
try {
List<UploadFile> list = qr.query(sql,new BeanListHandler(UploadFile.class));
return list;
} catch(SQLException e) {
thrownew RuntimeException(e);
}
}
@Override
publicvoid insert(UploadFile f) {
QueryRunner qr = new QueryRunner(DBManager.getDataSource());
String sql = "insert into uploadfile(id,uuidname,realname,savepath,uptime,description,username)value(?,?,?,?,?,?,?)";
Object []obj={f.getId(),f.getUuidname(),f.getRealname(),f.getSavepath(),f.getUptime(),f.getDescription(),f.getUsername()};
try {
qr.update(sql,obj);
} catch(SQLException e) {
thrownew RuntimeException(e);
}
}
}
服务层的接口和实现类：
import java.util.List;
importwww.hbsi.domain.UploadFile;
public interfaceBusinessServiceDao {
public voidinsert(UploadFile f);
public UploadFilegetUploadFile(String id);
publicList<UploadFile> getUploadFiles();
}
实现类：
publicclass BusinessServiceDaoImpl implements BusinessServiceDao{
UploadFileDao ufd = new UploadFileDaoImpl();
@Override
public UploadFilegetUploadFile(String id) {
returnufd.getUploadFile(id);
}
@Override
publicList<UploadFile> getUploadFiles() {
returnufd.getUploadFiles();
}
@Override
publicvoid insert(UploadFile f) {
ufd.insert(f);
}
}
DownLoadServlet类：
publicclass DownLoadServletextends HttpServlet {
publicvoid doGet(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
UploadFile fu;
String id = request.getParameter("id");
BusinessServiceDao bsd =new BusinessServiceDaoImpl();
try{
fu = bsd.getUploadFile(id);
}catch(Exception e){
request.setAttribute("message", "下载的资源不存在！");
request.getRequestDispatcher("/WEB-INF/manager/message.jsp").forward(request, response);
return;
}
String filename =fu.getSavepath()+fu.getRealname();
// 这句话必须得加且放在流关闭之前
response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(fu.getRealname(),"utf-8"));
FileInputStream fis = new FileInputStream(newFile(filename));
OutputStream os = response.getOutputStream();
byte [] buf= newbyte[1024];
int len=0;
while((len=fis.read(buf))>0){
os.write(buf, 0, len);
}
os.close();
fis.close();
}
publicvoid doPost(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
doGet(request, response);
}
}
ShowAllUploadFiles类：
publicclass ShowAllUploadFilesextends HttpServlet {
publicvoid doGet(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
BusinessServiceDao bsd =new BusinessServiceDaoImpl();
List<UploadFile> list = bsd.getUploadFiles();
request.setAttribute("list", list);
request.getRequestDispatcher("/WEB-INF/manager/showfiles.jsp").forward(request, response);
}
publicvoid doPost(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
doGet(request, response);
}
}
UDJumpServlet类：
publicclass UDJumpServletextends HttpServlet {
publicvoid doGet(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
request.getRequestDispatcher("WEB-INF/manager/ud.jsp").forward(request, response);
}
publicvoid doPost(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
doGet(request, response);
}
}
UploadJumpServlet类：
publicclass UploadJumpServletextends HttpServlet {
publicvoid doGet(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
request.getRequestDispatcher("/WEB-INF/manager/upload.jsp").forward(request, response);
}
publicvoid doPost(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
doGet(request, response);
}
}
publicclass UploadServletextends HttpServlet {
publicvoid doGet(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
UploadFile uf=null;
String rootPath=this.getServletContext().getRealPath("/WEB-INF/upload");
try {
uf = DBUpload.doUpload(request,rootPath,UploadFile.class);
}catch (Exception e) {
request.setAttribute("message", "文件上传失败！");
request.getRequestDispatcher("/WEB-INF/manager/message.jsp").forward(request, response);
e.printStackTrace();
return;
}
try{
BusinessServiceDao bsd = newBusinessServiceDaoImpl();
bsd.insert(uf);
request.setAttribute("message", "文件上传成功！");
}catch(Exception e){
request.setAttribute("message", "文件上传成功但保存失败！");
}
request.getRequestDispatcher("/WEB-INF/manager/message.jsp").forward(request,response );
}
publicvoid doPost(HttpServletRequest request, HttpServletResponseresponse)
throwsServletException, IOException {
doGet(request, response);
}
}
工具类：
获取连接：
publicclass DBManager {
staticComboPooledDataSource cpds;
static {
cpds= new ComboPooledDataSource("mysql");
}
publicstatic DataSource getDataSource(){
returncpds;
}
}
实现文件上传：
publicclass DBUpload {
publicstatic <T> UploadFile doUpload(HttpServletRequestrequest,String rootPath,Class<T>clazz) throwsException{
UploadFile uf = (UploadFile) clazz.newInstance();
DiskFileItemFactory factory=new DiskFileItemFactory();
String tempPath=request.getSession().getServletContext().getRealPath("/temp");
factory.setRepository(new File(tempPath));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setHeaderEncoding("utf-8");
List<FileItem> list= upload.parseRequest(request);
for(FileItem item:list){
if(item.isFormField()){
String filename = item.getFieldName();
String filevalue = item.getString();
BeanUtils.setProperty(uf, filename, filevalue);
}else{
String filename =item.getName();
String realname = filename.substring(filename.lastIndexOf("\\")+1);
String uuidname = getUUID(realname);
String savepath=getBranchFolders(realname,rootPath);
uf.setRealname(realname);
uf.setUuidname(uuidname);
uf.setSavepath(savepath);
uf.setId(UUID.randomUUID().toString());
uf.setUptime(new Date());
InputStream is = item.getInputStream();
FileOutputStream fos = new FileOutputStream(newFile(savepath+realname));
int len=0;
byte buf [] = newbyte[1024];
while((len=is.read(buf))>0){
fos.write(buf, 0, len);
}
fos.close();
is.close();
item.delete();
}
}
return uf;
}
privatestatic String getBranchFolders(String realname, StringrootPath) {
intf1=realname.hashCode()&4;
intf2=(realname.hashCode()&4)>>4;
String savePath=rootPath+"\\"+f1+"\\"+f2+"\\";
File file = newFile(savePath);
if(!file.exists()){
file.mkdirs();
}
returnsavePath;
}
privatestatic String getUUID(String realname) {
Stringext=realname.substring(realname.lastIndexOf(".")+1);
return UUID.randomUUID().toString()+ext;
}
}
Web层：
index.jsp
<html>
<frameset rows="20%,*">
<frame name="head" src="UDJumpServlet">
<frame name="body" src="">
</frameset>
</html>
message.jsp
<html>
<body>
${message}
</body>
</html>
showfiles.jsp
<html>
<body>
<table border ="1px" width="50%" align="center">
<CAPTION>文件下载区</CAPTION>
<thead>
<th>文件名</th>
<th>上传者</th>
<th>上传时间</th>
<th>文件描述</th>
<th>操作</th>
</thead>
<tbody>
<c:forEach var ="file"items="${list}">
<c:url var="url" value="DownLoadServlet">
<c:param name="id"value="${file.id}"/>
</c:url>
<tr><td>${file.realname}</td>
<td>${file.username}</td>
<td>${file.uptime}</td>
<td>${file.description}</td>
<td><a href = "${url}">下载</a></td>
</tr>
</c:forEach>
</tbody>
</table>
</body>
</html>
ud.jsp <html> <body> <h2 align="center">文件上传与下载</h2> <table align="center"> <tr><td><a href="UploadJumpServlet" target="body">上传</a></td><td></td><td></td><td><a href="ShowAllUploadFiles" target="body">下载</a></td></tr> </table> </body> </html>
upload.jsp
<html>
<body >
<form action="${pageContext.request.contextPath}/UploadServlet" method="post"enctype="multipart/form-data">
<table align="center" border="1px" width="50%">
<tr><td width="100px">上传者：</td><td><input type="text" name="username"/></td></tr>
<tr><td width="100px">选择文件：</td><td><input type="file" name="file"/></td></tr>
<tr><td width="100px">资源描述：</td><td><textarea cols="70" rows="5"name="description"></textarea></td></tr>
<tr><td align="center" colspan="2"><input type="submit" value="上传"/></td></tr>
</table>
</form>
</body>
</html>
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第1张图片](http://img.e-com-net.com/image/info5/cd9d3f8ddeca43b4a2510e18a07c7454.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第2张图片](http://img.e-com-net.com/image/info5/3dbf5369b4af4712af8faf4e3859b455.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第3张图片](http://img.e-com-net.com/image/info5/c494a050b7764986bd285e09700cc03c.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第4张图片](http://img.e-com-net.com/image/info5/63914537c2e840d4bdf74e36d68200e8.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第5张图片](http://img.e-com-net.com/image/info5/b0db12b2885f4ff5b79fc677d16342d9.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第6张图片](http://img.e-com-net.com/image/info5/fb5eb949f9594c48ba01063278bbd37a.png)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第7张图片](http://img.e-com-net.com/image/info5/d1e86d43a76645aabdf9f33b1e30187a.jpg)
![[置顶] 深入体验javaWeb开发内幕——问件的上传与下载案例实现_第8张图片](http://img.e-com-net.com/image/info5/ccc70d8510fc45e69648c00cf131a055.jpg)
好了，自己试试吧！