这个小程序有以下功能：
上传照片、下载图片、浏览图片、删除图片(需要权限)
这个程序为了省事，dao层也没有分成接口、实现类和工厂类三个部分，就直接在dao的类中实现了想要的功能了
网页就相当于是表现层，值对象也写，servlet其实就相当于业务逻辑层了
此程序需要使用到几个jar包，导入到WEB-INF下的lib目录下：
用于文件传输：commons-fileupload-1.2.2.jar和commons-io-2.1.jar
don4j对xml文件操作：dom4j-1.6.1.jar和jaxen-1.1-beta-6.jar
在项目src下要建立一个xml文件存放上传的相片的信息，这个文件里面写上一对<photos></photos>标签，每上传一张照片就增加一对<photo>标签作为<photos>的子节点，其中photo中要添加照片的属性 id , 原文件名realName , 扩展名ext , 路径dir , 上传时间dateTime , ip地址；然后每个photo增加一个子节点<description>，其中设置text存放照片描述信息。
表现层：
主页index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>上传照片upload.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<h2>小相册</h2>
<a href="jsps/upload.jsp">上传照片</a><br/>
<a href="showServlet">查看相册</a>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
</head>
<body>
<h2>相片上传</h2>
<form action="<%=request.getContextPath() %>/uploadServlet" method="post" enctype="multipart/form-data">
文件: <input type="file" name="file" /><br/>
说明: <input type="text" name="description" /><br/>
<input type="submit" value="上传" />
</form>
<br/>
<a href='javascript:history.go(-1)'>返回</a>
</body>
</html>
值对象：
PhotoModel.java
package cn.hncu.vo;
public class PhotoModel {
private String uuid;
private String realName;
private String ext;
private String dir;
private String dateTime;
private String ip;
private String description;
public String getUuid() {
return uuid;
}
public void setUuid(String uuid) {
this.uuid = uuid;
}
public String getRealName() {
return realName;
}
public void setRealName(String realName) {
this.realName = realName;
}
public String getExt() {
return ext;
}
public void setExt(String ext) {
this.ext = ext;
}
public String getDir() {
return dir;
}
public void setDir(String dir) {
this.dir = dir;
}
public String getDateTime() {
return dateTime;
}
public void setDateTime(String dateTime) {
this.dateTime = dateTime;
}
public String getIp() {
return ip;
}
public void setIp(String ip) {
this.ip = ip;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
@Override
public String toString() {
return "PhotoModel [uuid=" + uuid + ", realName=" + realName + ", ext="
+ ext + ", dir=" + dir + ", dateTime=" + dateTime + ", ip="
+ ip + ", description=" + description + "]";
}
}
业务逻辑层：
上传照片UploadServlet.java
package cn.hncu.servlets;浏览相册ShowServlet.java
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FileUtils;
import cn.hncu.dao.PhotoDAO;
import cn.hncu.utils.MyUtils;
import cn.hncu.vo.PhotoModel;
public class UploadServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print("不支持get方式提交");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
//处理上传文件
DiskFileItemFactory factory=new DiskFileItemFactory();
factory.setRepository(new File("D:/a/b"));
ServletFileUpload upload=new ServletFileUpload(factory);
upload.setSizeMax(1024*1024*100);
request.setCharacterEncoding("utf-8");
FileItem fi=null;
try {
List<FileItem> list=upload.parseRequest(request);
InputStream in=null;
boolean boo=false;
PhotoModel photo=new PhotoModel();
//for循环是把photo的信息封装完整，，，之后(for之后)才能把该photo对象保存到数据库
for (FileItem fii:list){
fi=fii;
if (fi.isFormField()){
String description=fi.getString("utf-8");
photo.setDescription(description);
} else {
in=fi.getInputStream();
String fileName=fi.getName();
if (fileName==null||fileName.trim().equals("")){
out.print("没有选择文件!<br/><a href='javascript:history.go(-1)'>返回</a>");
return;
} else {
fileName=fileName.substring(fileName.lastIndexOf("/")+1);
photo.setRealName(fileName);//文件名
String ext=fileName.substring(fileName.lastIndexOf("."));
photo.setExt(ext);//后缀名
photo.setDateTime(MyUtils.getCurrentTime());//时间
photo.setUuid(MyUtils.getUuid());//id
photo.setDir(MyUtils.getDir(photo.getUuid()));//目录
photo.setIp(request.getRemoteAddr());//ip地址
}
}
}
//把相片信息存储到数据库
PhotoDAO dao=new PhotoDAO();
boo=dao.save(photo);
//如果上面的相片信息保存成功，那么才开始接收图片文件，把它保存到服务器硬盘
if (boo){
String path=getServletContext().getRealPath("/photos");
path=path+"/"+photo.getDir();
File file=new File(path);
if (!file.exists()){
file.mkdirs();
}
String fileName2=path+"/"+photo.getUuid()+photo.getExt();
FileUtils.copyInputStreamToFile(in, new File(fileName2));
out.print("上传成功!<br/><a href='javascript:history.go(-1)'>返回</a>");
} else {
out.print("上传失败!<br/><a href='javascript:history.go(-1)'>返回</a>");
}
} catch (FileUploadException e) {
throw new RuntimeException("上传失败", e);
} finally {
if (fi!=null){
fi.delete();
}
}
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
}
package cn.hncu.servlets;import java.io.IOException;import java.io.PrintWriter;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.hncu.dao.PhotoDAO;import cn.hncu.vo.PhotoModel;public class ShowServlet 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 {response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println(" <BODY>");String table="<table border=1px width=600px >"+ "<tr><th>文件名</th> <th>上传时间</th> <th>图片</th> <th>说明</th> <th>操作</th></tr>";out.print(table);//显示所有的图片PhotoDAO dao=new PhotoDAO();List<PhotoModel> list=dao.getAll();for (PhotoModel model:list){out.print("<tr>");out.print("<td width=100>"+model.getRealName()+"</td>");out.print("<td width=100>"+model.getDateTime()+"</td>");String path=request.getContextPath()+"/photos/"+model.getDir()+"/"+model.getUuid()+model.getExt();out.print("<td><a href='"+path+"'><img height=200 width=200 src='"+path+"'/></a></td>");out.print("<td width=100>"+model.getDescription()+"</td>");String strDelete="<a href='"+request.getContextPath()+"/deleteServlet?id="+model.getUuid()+"'>删除</a>";String strDownload="<a href='"+request.getContextPath()+"/downloadServlet?id="+model.getUuid()+"'>下载</a>";String str=strDownload+" "+strDelete;out.print("<td width=100>"+str+"</td>");out.print("</tr>");}out.print("</table>");out.println(" </BODY>");out.println("</HTML>");out.flush();out.close();}}下载文件DownloadServlet.java
package cn.hncu.servlets;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.PrintWriter;import java.net.URLEncoder;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.hncu.dao.PhotoDAO;import cn.hncu.vo.PhotoModel;public class DownloadServlet 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 {PhotoDAO dao=new PhotoDAO();String id=request.getParameter("id");PhotoModel photo=dao.getSingleById(id);if (photo!=null){response.setContentType("application/force-download");String realName=photo.getRealName();realName=URLEncoder.encode(realName, "utf-8");//设置响应头，以让客户端软件下载时能够显示该文件名response.setHeader("content-disposition", "attachment;filename='"+realName+"'");String fileName="photos/"+photo.getDir()+"/"+photo.getUuid()+photo.getExt();String filePathName=getServletContext().getRealPath(fileName);InputStream in=new FileInputStream(new File(filePathName));OutputStream out=response.getOutputStream();int len=0;byte[] buf=new byte[1024];while ((len=in.read(buf))!=-1){out.write(buf, 0, len);}out.close();} else {response.setContentType("text/html;charset=utf-8");PrintWriter out=response.getWriter();out.print("该文件已被删除");out.print("<br/><a href='javascript:history.go(-1)'>返回</a>");}}}
删除照片DeleteServlet.java
package cn.hncu.servlets;import java.io.File;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.hncu.dao.PhotoDAO;import cn.hncu.vo.PhotoModel;public class DeleteServlet 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 {response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();String id=request.getParameter("id");String ip=request.getRemoteAddr();PhotoDAO dao=new PhotoDAO();PhotoModel photo=dao.getSingleById(id);if (photo!=null){if (!ip.equals(photo.getIp())){out.print("你无权删除!<br/><a href='javascript:history.go(-1)'>返回</a>");return;}//1删除数据库中的信息boolean boo=dao.delete(photo.getUuid());//2把服务器硬盘中的文件删除if (boo){String fileName="photos/"+photo.getDir()+"/"+photo.getUuid()+photo.getExt();String filePathName=getServletContext().getRealPath(fileName);File file=new File(filePathName);if (file.exists()){file.delete();}String showPath=getServletContext().getContextPath()+"/showServlet";out.print("删除成功!<br/><a href='"+showPath+"'>浏览相册</a>");} else {out.print("相片删除失败<br/><a href='javascript:history.go(-1)'>返回</a>");}} else {out.print("该文件不存在<br/><a href='javascript:history.go(-1)'>返回</a>");}}}
PhotoDAO.java
package cn.hncu.dao;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.dom4j.Document;
import org.dom4j.Element;
import cn.hncu.utils.Dom4jFactory;
import cn.hncu.vo.PhotoModel;
public class PhotoDAO {
public boolean save(PhotoModel model){
Document dom=Dom4jFactory.getDom();
Element root=dom.getRootElement();
Element photoElement=root.addElement("photo");
photoElement.addAttribute("id", model.getUuid());
photoElement.addAttribute("ip", model.getIp());
photoElement.addAttribute("realName", model.getRealName());
photoElement.addAttribute("dir", model.getDir());
photoElement.addAttribute("ext", model.getExt());
photoElement.addAttribute("dateTime", model.getDateTime());
photoElement.addAttribute("description", model.getDescription());
boolean boo=Dom4jFactory.save();
return boo;
}
public List<PhotoModel> getAll(){
List<PhotoModel> list=new ArrayList<PhotoModel>();
Element root=Dom4jFactory.getDom().getRootElement();
Iterator<Element> it=root.elementIterator("photo");
while (it.hasNext()){
PhotoModel model=new PhotoModel();
Element e=it.next();
model.setDateTime(e.attributeValue("dateTime"));
model.setDir(e.attributeValue("dir"));
model.setExt(e.attributeValue("ext"));
model.setIp(e.attributeValue("ip"));
model.setRealName(e.attributeValue("realName"));
model.setUuid(e.attributeValue("id"));
model.setDescription(e.elementText("description"));
list.add(model);
}
return list;
}
public PhotoModel getSingleById(String uuid){
List<PhotoModel> list=getAll();
for (PhotoModel p:list){
if (p.getUuid().equals(uuid)){
return p;
}
}
return null;
}
public boolean delete(String id){
Document dom=Dom4jFactory.getDom();
Element e=(Element) dom.selectSingleNode("//photo[@id='"+id+"']");
return e.getParent().remove(e);
}
}
工具类
MyUtils.java
package cn.hncu.utils;Dom4jFactory.java
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;
public class MyUtils {
public static String getUuid(){
return UUID.randomUUID().toString().replace("-", "");
}
public static String getDir(String uuid){
String dir1=Integer.toHexString(uuid.hashCode() & 0xf);
String dir2=Integer.toHexString((uuid.hashCode() & 0xf0)>>4);
String dir=dir1+"/"+dir2;
return dir;
}
private static SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
public static String getCurrentTime(){
return format.format(new Date());
}
}
package cn.hncu.utils;import java.text.SimpleDateFormat;import java.util.Date;import java.util.UUID;public class MyUtils {public static String getUuid(){return UUID.randomUUID().toString().replace("-", "");}public static String getDir(String uuid){String dir1=Integer.toHexString(uuid.hashCode() & 0xf);String dir2=Integer.toHexString((uuid.hashCode() & 0xf0)>>4);String dir=dir1+"/"+dir2;return dir;}private static SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");public static String getCurrentTime(){return format.format(new Date());}}
主页：
上传照片：
浏览相册：
