功能文件的上传，下载和管理
技术：1.用xml当做数据库存储信息（dom4j，xpath)
2.Java表单的文件上传和下载
3.文件目录的打散 （ Hash目录是一种优化文件存储性能的方法）
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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先写index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>相册管理系统</title> </head> <body> <h1>我的小相册</h1> <a href="jsps/upload.jsp">上传相册</a> <a href="servlets/ShowServlet">浏览相册</a> </body> </html>
upload.jsp是下载页面放在jsps目录下
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body> <h1>相处上传</h1> <form action="<%=request.getContextPath()%>/servlets/UploadServlet" method="post" enctype="multipart/form-data"> 文件:<input type="file" name="file1"/><br/> 说明:<input type="text" name="desc" /><br/> <input type="submit" value="上传" /> </form> </body> </html>
photos.xml放在src目录下
<"1.0" encoding="UTF-8"?> <photos> </photos>
在写值对象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 + "]"; } }
写工具类两个：
MyUtil（日期格式化，目录打散代码，随机id代码)
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的相关操作，获取document对象，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(); // 学习一下服务器下的资源路径加载方式(因为我们的资源已经从MyEclipse中发布到Tomcat服务器中了，所以跟原来纯Java项目不一样了) // 利用当前类找到它的类加载器，然后通过该类加载器再去获得资源路径 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; } } }
从底层写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; } //浏览 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); } }
最后写四个servlet
UploadServlet 上传Servlet代码
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方式上传!"); 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");//用于设置文件名的编码，相当于：request.setCharacterEncoding("utf-8"); FileItem fi=null; try { List<FileItem> list=upload.parseRequest(request); PhotoModel photo = new PhotoModel();//数据封装---需要7个属性 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("没有选择文件!"); return; } if(realName.indexOf("")!=-1){ realName=realName.substring(realName.lastIndexOf("")+1); } photo.setRealName(realName);//真实文件名 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 } } //把相片信息存储到数据库 PhotoDao dao=new PhotoDao(); boo=dao.add(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){ 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("上传成功!<a href='"+strPath+"'>浏览相册</a>"); }else{ out.print("上传失败!"); } } catch (FileUploadException e) { throw new RuntimeException("上传失败！", e); }finally{ if(fi!=null){ fi.delete(); } } out.flush(); out.close(); } }
ShowServlet 浏览相册的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>上传ip</th><th>上传时间</th><th>图片</th><th>说明</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>"); //输出图片 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"'>删除</a>"; out.println("<td>"+p.getDesc()+"</td>"); op+="<a href='"+request.getContextPath()+"/servlets/DownServlet"'>下载</a>"; out.println("<td>"+op+"</td>"); out.print("</tr>"); } out.println("</table>"); out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); } }
DownServlet 下载的服务器代码
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("该文件已经被删除!"); } } }
Delservlet 删除操作的服务器
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("你无权进行删除！"); return; } //※※※※以下部分课后补敲的!!!! //1删除数据库中的信息 PhotoDao dao=new PhotoDao(); boolean boo=dao.del(id); //2把服务器硬盘中的文件删除 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("相片删除成功!<a href='"+strPath+"'>浏览相册</a>"); }else{ out.println("相片删除失败!"); } }else{ response.setContentType("text/html;charset=utf-8"); response.getWriter().println("该文件不存在!"); } } }
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。