发布于 2017-11-25 00:55:24 | 95 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Java函数式编程,程序狗速度看过来!

Java程序设计语言

java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se))的总称。


这篇文章主要为大家详细介绍了相册管理系统的实现步骤,Java表单的文件上传和下载,xml数据库存储信息,感兴趣的小伙伴们可以参考一下

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

--------------------------------------------------------------------------------

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


<?xml version="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?id="+p.getId()+"'>删除</a> ";
   out.println("<td>"+p.getDesc()+"</td>");
   op+="<a href='"+request.getContextPath()+"/servlets/DownServlet?id="+p.getId()+"'>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PHPERZ。



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