功能文件的上傳，下載和管理技術：1.用xml當做數據庫存儲信息（dom4j，xpath)
2.Java表單的文件上傳和下載
3.文件目錄的打散（ Hash目錄是一種優化文件存儲性能的方法）
需要的jar包：
commons-fileupload-1.2.2.jar、commons-io-2.1.jar、dom4j-1.6.1.jar和jaxen-1.1-beta-6.jar
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先寫index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>相冊管理系統</title> </head> <body> <h1>我的小相冊</h1> <a href="jsps/upload.jsp">上傳相冊</a> <a href="servlets/ShowServlet">瀏覽相冊</a> </body></html>
upload.jsp是下載頁面放在jsps目錄下
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> </head> <body> <h1>相處上傳</h1> <form action="<%=request.getContextPath()%>/servlets/UploadServlet" method="post" enctype="multipart/form-data"> 文件:<input type="file" name="file1"/><br/> 說明:<input type="text" name="desc" /><br/> <input type="submit" value="上傳" /> </form> </body></html>
photos.xml放在src目錄下
<?xml version="1.0" encoding="UTF-8"?><photos></photos>
在寫值對象PhotoModel
package cn.hncu.demain;public class PhotoModel { private String id; private String realName; private String ext; private String dir; private String dateTime; private String ip; private String desc; public String getId() { return id; } public void setId(String id) { this.id = id; } 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 getDesc() { return desc; } public void setDesc(String desc) { this.desc = desc; } @Override public String toString() { return "PhotoModel [id=" + id + ", realName=" + realName + ", ext=" + ext + ", dir=" + dir + ", dateTime=" + dateTime + ", ip=" + ip + ", desc=" + desc + "]"; }}寫工具類兩個：
MyUtil（日期格式化，目錄打散代碼，隨機id代碼)
package cn.hncu.utils;import java.text.SimpleDateFormat;import java.util.Date;import java.util.UUID;public class MyUtils { private MyUtils() { } private static SimpleDateFormat format=new SimpleDateFormat("yyyy年MM月dd日hh:mm:ss"); public static String getCurrentDateTime(){ return format.format(new Date()); } public static String getUUid(){ UUID uuid=UUID.randomUUID(); String id=uuid.toString().replaceAll("-", ""); return id; } public static String getDir(String uuid){ String dir1=Integer.toHexString(uuid.hashCode() & 0xf); String dir2=Integer.toHexString((uuid.hashCode() & 0xf0)>>4); return dir1+"/"+dir2; }}Dom4jFactory(dom4j的相關操作，獲取document對象，保存操作)
package cn.hncu.utils;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.UnsupportedEncodingException;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;public class Dom4jFactory { private static Document dom = null; private static String path; static { try { SAXReader sax = new SAXReader(); // 學習一下服務器下的資源路徑加載方式(因為我們的資源已經從MyEclipse中發佈到Tomcat服務器中了，所以跟原來純Java項目不一樣了) // 利用當前類找到它的類加載器，然後通過該類加載器再去獲得資源路徑path = Dom4jFactory.class.getClassLoader().getResource("photos.xml") .getPath(); dom = sax.read(new FileInputStream(path)); } catch (Exception e) { throw new RuntimeException(e.getMessage(), e); } } public static Document getDom(){ return dom; } public static boolean save(){ try { OutputFormat format=new OutputFormat(); format.setEncoding("utf-8"); XMLWriter w = new XMLWriter( new FileOutputStream(new File(path)),format); w.write(dom); w.close(); return true; } catch (Exception e) { return false; } }}從底層寫PhotoDao
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.demain.PhotoModel;import cn.hncu.utils.Dom4jFactory;public class PhotoDao { //添加public boolean add(PhotoModel photo){ Document dom=Dom4jFactory.getDom(); Element root=dom.getRootElement(); Element ePhoto=root.addElement("photo"); ePhoto.addAttribute("id", photo.getId()); ePhoto.addAttribute("realName", photo.getRealName()); ePhoto.addAttribute("dir", photo.getDir()); ePhoto.addAttribute("ip", photo.getIp()); ePhoto.addAttribute("dateTime", photo.getDateTime()); ePhoto.addAttribute("ext", photo.getExt()); ePhoto.addElement("desc").setText(photo.getDesc()); boolean boo=Dom4jFactory.save(); return boo; } //瀏覽public List<PhotoModel> getAll(){ Document dom=Dom4jFactory.getDom(); List<PhotoModel> list=new ArrayList<PhotoModel>(); Element root=dom.getRootElement(); Iterator<Element> it=root.elementIterator(); while(it.hasNext()){ PhotoModel photo=new PhotoModel(); Element e=it.next(); photo.setId(e.attributeValue("id")); photo.setDateTime(e.attributeValue("dateTime")); photo.setDir(e.attributeValue("dir")); photo.setExt(e.attributeValue("ext")); photo.setIp(e.attributeValue("ip")); photo.setRealName(e.attributeValue("realName")); photo.setDesc(e.elementText("desc")); list.add(photo); } return list; } public PhotoModel getSingleById(String id) { Document dom=Dom4jFactory.getDom(); List<PhotoModel> list=getAll(); for(PhotoModel photo:list){ if(photo.getId().equals(id)){ return photo; } } return null; } public boolean del(String id) { Document dom=Dom4jFactory.getDom(); Element e=(Element) dom.selectSingleNode("//photo[@id='"+id.trim()+"']"); return e.getParent().remove(e); }}最後寫四個servlet
UploadServlet 上傳Servlet代碼
package cn.hncu.servlets;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.demain.PhotoModel;import cn.hncu.utils.MyUtils;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.println("不支持get方式上傳!"); 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(); String path=request.getServletContext().getRealPath("/photos"); DiskFileItemFactory factory=new DiskFileItemFactory(); factory.setRepository(new File("g:/a")); ServletFileUpload upload = new ServletFileUpload(factory); upload.setSizeMax(1024*1024*10);//最大10M upload.setHeaderEncoding("utf-8");//用於設置文件名的編碼，相當於：request.setCharacterEncoding("utf-8"); FileItem fi=null; try { List<FileItem> list=upload.parseRequest(request); PhotoModel photo = new PhotoModel();//數據封裝---需要7個屬性boolean boo=false; InputStream in = null; for(FileItem fi2:list){ fi=fi2; if(fi.isFormField()){ String desc=fi.getString("utf-8"); photo.setDesc(desc);//desc }else{ in=fi.getInputStream(); String realName=fi.getName(); if(realName==null || realName.trim().equals("")){ out.print("沒有選擇文件!"); return; } if(realName.indexOf("//")!=-1){ realName=realName.substring(realName.lastIndexOf("//")+1); } photo.setRealName(realName);//真實文件名String ext=realName.substring(realName.lastIndexOf(".")); photo.setExt(ext);//3 photo.setDateTime(MyUtils.getCurrentDateTime());//4 photo.setId(MyUtils.getUUid());//5 photo.setDir(MyUtils.getDir(photo.getId()));//6 photo.setIp(request.getRemoteAddr());//7 } } //把相片信息存儲到數據庫PhotoDao dao=new PhotoDao(); boo=dao.add(photo); //如果上面的相片信息保存成功，那麼才開始接收圖片文件，把它保存到服務器硬盤if(boo){ System.out.println(dao); path=path+"/"+photo.getDir(); File dir=new File(path); if(!dir.exists()){ dir.mkdirs(); } String fileName=path+"/"+photo.getId()+photo.getExt(); FileUtils.copyInputStreamToFile(in, new File(fileName)); String strPath = request.getContextPath()+"/servlets/ShowServlet"; out.print("上傳成功!<a href='"+strPath+"'>瀏覽相冊</a>"); }else{ out.print("上傳失敗!"); } } catch (FileUploadException e) { throw new RuntimeException("上傳失敗！ ", e); }finally{ if(fi!=null){ fi.delete(); } } out.flush(); out.close(); }}ShowServlet 瀏覽相冊的Servlet端
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.demain.PhotoModel;public class ShowServlet extends HttpServlet { IOException if an error occurred 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"); request.setCharacterEncoding("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='1' width='100%'>"+ "<tr><th>文件名</th><th>上傳ip</th><th>上傳時間</th><th>圖片</th><th>說明</th><th>操作</th></tr>" ; out.print(table); PhotoDao dao=new PhotoDao(); List<PhotoModel> list=dao.getAll(); for(PhotoModel p:list){ out.print("<tr>"); out.println("<td>"+p.getRealName()+"</td>"); out.println("<td>"+p.getIp()+"</td>"); out.println("<td>"+p.getDateTime()+"</td>"); //輸出圖片String path=request.getContextPath()+"/photos/"+p.getDir()+"/"+p.getId()+p.getExt(); out.println("<td><a href='"+path+"'><img src='"+path+"' width='200' height='200'></img></a></td>"); String op="<a href='"+request.getContextPath()+"/servlets/DelServlet?id="+p.getId()+"'>刪除</a>"; out.println("<td>"+p.getDesc()+"</td>"); op+="<a href='"+request.getContextPath()+"/servlets/DownServlet?id="+p.getId()+"'>下載</a>"; out.println("<td>"+op+"</td>"); out.print("</tr>"); } out.println("</table>"); out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); }}DownServlet 下載的服務器代碼
package cn.hncu.servlets;import java.io.FileInputStream;import java.io.FileOutputStream;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.demain.PhotoModel;public class DownServlet 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 { String id=request.getParameter("id"); response.setContentType("application/force-download"); PhotoModel p=new PhotoDao().getSingleById(id); if(p!=null){ String realName=p.getRealName(); realName=new String(realName.getBytes("iso8859-1"),"utf-8"); response.setHeader("content-Disposition", "attachment;filename=/""+realName+"/""); String relpath=getServletContext().getRealPath("/photos/"+p.getDir()+"/"+p.getId()+p.getExt()); InputStream in=new FileInputStream(relpath); OutputStream out=response.getOutputStream(); System.out.println(relpath); byte buf[]=new byte[1024]; int len=0; while ((len=in.read(buf))!=-1){ out.write(buf,0,len); } out.close(); }else{ response.setContentType("text/html;charset=utf-8"); response.getWriter().println("該文件已經被刪除!"); } }}Delservlet 刪除操作的服務器
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 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.demain.PhotoModel;public class DelServlet 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 { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out=response.getWriter(); String id=request.getParameter("id"); PhotoModel p=new PhotoDao().getSingleById(id); if(p!=null){ if(!p.getIp().equals(request.getRemoteAddr())){ out.println("你無權進行刪除！ "); return; } //※※※※以下部分課後補敲的!!!! //1刪除數據庫中的信息PhotoDao dao=new PhotoDao(); boolean boo=dao.del(id); //2把服務器硬盤中的文件刪除if(boo){ String fileName="photos/"+p.getDir()+"/"+p.getId()+p.getExt(); String pathFileName = getServletContext().getRealPath(fileName); File f=new File(pathFileName); if(f.exists()){ f.delete(); } String strPath = request.getContextPath()+"/servlets/ShowServlet"; out.println("相片刪除成功!<a href='"+strPath+"'>瀏覽相冊</a>"); }else{ out.println("相片刪除失敗!"); } }else{ response.setContentType("text/html;charset=utf-8"); response.getWriter().println("該文件不存在!"); } }}以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。