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    Jsp+Servlet实现文件上传下载 文件列表展示(二)

    接着上一篇讲:
    Jsp+Servlet实现文件上传下载(一)--文件上传

    本章来实现一下上传文件列表展示,同时优化了一下第一章中的代码。

    废话少说,上代码

    mysql创建附件表

    DROP TABLE tbl_accessory; 
     
    CREATE TABLE tbl_accessory 
    ( 
     id INT AUTO_INCREMENT PRIMARY KEY, 
     file_name VARCHAR(500), 
     file_size DOUBLE(10,2), 
     file_ext_name VARCHAR(100), 
     file_path VARCHAR(2000) 
    ) 
    ; 
     
    SELECT * FROM tbl_accessory; 
     
    DELETE FROM tbl_accessory; 
    

    创建附件实体类

    package entity.upload; 
     
    /** 
     * 附件实体类 
     * 
     * @author xusucheng 
     * @create 2017-12-29 
     **/ 
    public class EntityAccessory { 
     private int id; 
     private String fileName; 
     private double fileSize; 
     private String file_ext_name; 
     private String filePath; 
     
     public int getId() { 
      return id; 
     } 
     
     public void setId(int id) { 
      this.id = id; 
     } 
     
     public String getFileName() { 
      return fileName; 
     } 
     
     public void setFileName(String fileName) { 
      this.fileName = fileName; 
     } 
     
     public double getFileSize() { 
      return fileSize; 
     } 
     
     public void setFileSize(double fileSize) { 
      this.fileSize = fileSize; 
     } 
     
     public String getFile_ext_name() { 
      return file_ext_name; 
     } 
     
     public void setFile_ext_name(String file_ext_name) { 
      this.file_ext_name = file_ext_name; 
     } 
     
     public String getFilePath() { 
      return filePath; 
     } 
     
     public void setFilePath(String filePath) { 
      this.filePath = filePath; 
     } 
    } 
    

    创建DBUtil工具类

    package util; 
     
    import java.sql.*; 
    import java.io.InputStream; 
    import java.util.Properties; 
     
    /** 
     * 数据库工具类 
     * 
     * @author xusucheng 
     * @create 2017-11-18 
     **/ 
    public class DBUtil { 
     //定义链接所需要的变量 
     private static Connection con = null; 
     private static PreparedStatement ps = null; 
     private static ResultSet rs = null; 
     
     //定义链接数据库所需要的参数 
     private static String url = ""; 
     private static String username = ""; 
     private static String driver=""; 
     private static String password=""; 
     
     //定义读取配置文件所需要的变量 
     private static Properties pp = null; 
     private static InputStream fis = null; 
     
     /** 
      * 加载驱动 
      */ 
     static { 
      try { 
       //从dbinfo.properties配置文件中读取配置信息 
       pp = new Properties(); 
       fis = DBUtil.class.getClassLoader().getResourceAsStream("db.properties"); 
     
       pp.load(fis); 
       url = pp.getProperty("url"); 
       username = pp.getProperty("username"); 
       driver=pp.getProperty("driver"); 
       password=pp.getProperty("password"); 
     
       //加载驱动 
       Class.forName(driver); 
     
      } catch (Exception e) { 
       System.out.println("驱动加载失败!"); 
       e.printStackTrace(); 
      } finally { 
       try { 
        fis.close(); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
     
       fis = null; //垃圾回收自动处理 
      } 
     
     } 
     
     /** 
      * 得到Connection链接 
      * @return Connection 
      */ 
     public static Connection getConnection() { 
     
      try { 
       //建立连接 
       con = DriverManager.getConnection(url, username, password); 
     
      } catch (Exception e) { 
       System.out.println("数据库链接失败!"); 
       e.printStackTrace(); 
      } 
     
      return con; 
     } 
     
     /*public DBUtil(String sql){ 
      try { 
       ps = getConnection().prepareStatement(sql);//准备执行语句 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     } 
     
     public void close() { 
      try { 
       con.close(); 
       ps.close(); 
      } catch (SQLException e) { 
       e.printStackTrace(); 
      } 
     }*/ 
     
     /** 
      * 统一的资源关闭函数 
      * @param rs 
      * @param ps 
      * @param con 
      */ 
     public static void close(ResultSet rs,Statement ps, Connection con){ 
     
      if(rs != null) { 
       try { 
        rs.close(); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
      if(ps != null) { 
       try { 
        ps.close(); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
      if(con != null) { 
       try { 
        con.close(); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
     } 
     
    } 
    

    创建附件实体DAO类

    package dao.upload; 
     
    import entity.upload.EntityAccessory; 
    import util.DBUtil; 
     
    import java.math.BigDecimal; 
    import java.sql.Connection; 
    import java.sql.PreparedStatement; 
    import java.sql.ResultSet; 
    import java.sql.SQLException; 
    import java.util.ArrayList; 
    import java.util.List; 
     
    /** 
     * 附件上传DAO 
     * 
     * @author xusucheng 
     * @create 2017-12-29 
     **/ 
    public class AccessoryDao { 
     public static void add(EntityAccessory entity) { 
      Connection conn = DBUtil.getConnection(); 
      String sql = "insert into tbl_accessory(file_name,file_size,file_ext_name,file_path) values(?,?,?,?)"; 
      try { 
       PreparedStatement ps = conn.prepareStatement(sql); 
       ps.setString(1, entity.getFileName()); 
       ps.setDouble(2, entity.getFileSize()); 
       ps.setString(3, entity.getFile_ext_name()); 
       ps.setString(4, entity.getFilePath()); 
       ps.execute(); 
       //conn.commit(); 
     
       DBUtil.close(null, ps, conn); 
      } catch (SQLException e) { 
       e.printStackTrace(); 
      } 
     } 
     
     public static ListEntityAccessory> list() { 
      Connection conn = DBUtil.getConnection(); 
      String sql = "select id,file_name,file_size,file_ext_name,file_path from tbl_accessory"; 
      ListEntityAccessory> accessoryList = new ArrayList>(); 
      try { 
       PreparedStatement ps = conn.prepareStatement(sql); 
       ResultSet rs = ps.executeQuery(); 
     
       while (rs.next()) { 
        EntityAccessory entity = new EntityAccessory(); 
        entity.setId(rs.getInt("id")); 
        entity.setFileName(rs.getString("file_name")); 
        entity.setFileSize(new BigDecimal(rs.getDouble("file_size") / 1024).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue()); 
        entity.setFile_ext_name(rs.getString("file_ext_name")); 
        entity.setFilePath(rs.getString("file_path")); 
        accessoryList.add(entity); 
       } 
     
       DBUtil.close(rs, ps, conn); 
      } catch (SQLException e) { 
       e.printStackTrace(); 
      } 
     
      return accessoryList; 
     
     } 
     
     public static void remove(int id) { 
      Connection conn = DBUtil.getConnection(); 
      String sql = "delete from tbl_accessory where id=?"; 
      try { 
       PreparedStatement ps = conn.prepareStatement(sql); 
       ps.setInt(1,id); 
       ps.execute(); 
       //conn.commit(); mysql默认开启了autocommit 
     
       DBUtil.close(null,ps,conn); 
      } catch (SQLException e) { 
       e.printStackTrace(); 
      } 
     } 
    } 
    

    创建list.jsp列表页面

    html> 
    head> 
     title>上传文件列表/title> 
    /head> 
    body> 
     
    h3>文件列表/h3> 
    table class="acclist_tab" border="1" bordercolor="#000000" cellspacing="0" cellpadding="2" style="border-collapse:collapse;"> 
     tr> 
      th>文件名/th> 
      th>文件大小(KB)/th> 
      th>操作/th> 
     /tr> 
     c:if test="${not empty accessoryList}"> 
      c:forEach items="${accessoryList}" var="acc"> 
       tr> 
        td>${acc.fileName}/td> 
        td>${acc.fileSize}/td> 
        td>a href="">删除/a>/td> 
       /tr> 
      /c:forEach> 
     /c:if> 
    /table> 
    /body> 
    /html> 
    

    创建展示列表Servlet:listUploadedFilesServlet

    package servlet.upload; 
     
    import dao.upload.AccessoryDao; 
    import entity.upload.EntityAccessory; 
     
    import javax.servlet.ServletException; 
    import javax.servlet.annotation.WebServlet; 
    import javax.servlet.http.HttpServlet; 
    import javax.servlet.http.HttpServletRequest; 
    import javax.servlet.http.HttpServletResponse; 
    import java.io.IOException; 
    import java.util.List; 
     
    /** 
     * 返回已上传文件列表 
     * 
     * @author xusucheng 
     * @create 2017-12-29 
     **/ 
     
    @WebServlet("/listUploadedFiles") 
    public class listUploadedFilesServlet extends HttpServlet { 
     @Override 
     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
      //获取文件列表 
      ListEntityAccessory> accessoryList = AccessoryDao.list(); 
      request.setAttribute("accessoryList", accessoryList); 
     
      request.getRequestDispatcher("pages/upload/list.jsp").forward(request, response); 
     } 
     
     @Override 
     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
      doPost(request, response); 
     } 
    } 
    

    增加error.jsp显示上传失败信息

    %@ page contentType="text/html;charset=UTF-8" language="java" %> 
    %@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
    html> 
    head> 
     title>上传错误页面/title> 
    /head> 
    body> 
     
    h3>上传失败:/h3> 
    c:if test="${not empty errorMessage}"> 
     %--input type="text" id="errorMessage" value="${errorMessage}" style="color:red;" disabled="disabled">--%> 
     h4 style="color: red;">${errorMessage}/h4> 
    /c:if> 
     
     
    /body> 
    /html> 

    优化了第一章中的上传控制器

    package servlet.upload; 
     
    import dao.upload.AccessoryDao; 
    import entity.upload.EntityAccessory; 
    import org.apache.commons.fileupload.FileItem; 
    import org.apache.commons.fileupload.FileUploadBase; 
    import org.apache.commons.fileupload.FileUploadException; 
    import org.apache.commons.fileupload.ProgressListener; 
    import org.apache.commons.fileupload.disk.DiskFileItemFactory; 
    import org.apache.commons.fileupload.servlet.ServletFileUpload; 
     
    import javax.servlet.ServletException; 
    import javax.servlet.annotation.WebServlet; 
    import javax.servlet.http.HttpServlet; 
    import javax.servlet.http.HttpServletRequest; 
    import javax.servlet.http.HttpServletResponse; 
    import java.io.File; 
    import java.io.FileOutputStream; 
    import java.io.IOException; 
    import java.io.InputStream; 
    import java.util.Calendar; 
    import java.util.Iterator; 
    import java.util.List; 
    import java.util.UUID; 
     
    /** 
     * 处理文件上传 
     * 
     * @author xusucheng 
     * @create 2017-12-27 
     **/ 
    @WebServlet("/UploadServlet") 
    public class UploadServlet extends HttpServlet { 
     @Override 
     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
      //设置文件上传基本路径 
      String savePath = this.getServletContext().getRealPath("/WEB-INF/uploadFiles"); 
      //设置临时文件路径 
      String tempPath = this.getServletContext().getRealPath("/WEB-INF/tempFiles"); 
      File tempFile = new File(tempPath); 
      if (!tempFile.exists()) { 
       tempFile.mkdir(); 
      } 
     
      //定义异常消息 
      String errorMessage = ""; 
      //创建file items工厂 
      DiskFileItemFactory factory = new DiskFileItemFactory(); 
      //设置缓冲区大小 
      factory.setSizeThreshold(1024 * 100); 
      //设置临时文件路径 
      factory.setRepository(tempFile); 
      //创建文件上传处理器 
      ServletFileUpload upload = new ServletFileUpload(factory); 
      //监听文件上传进度 
      ProgressListener progressListener = new ProgressListener() { 
       public void update(long pBytesRead, long pContentLength, int pItems) { 
        System.out.println("正在读取文件: " + pItems); 
        if (pContentLength == -1) { 
         System.out.println("已读取: " + pBytesRead + " 剩余0"); 
        } else { 
         System.out.println("文件总大小:" + pContentLength + " 已读取:" + pBytesRead); 
        } 
       } 
      }; 
      upload.setProgressListener(progressListener); 
     
      //解决上传文件名的中文乱码 
      upload.setHeaderEncoding("UTF-8"); 
      //判断提交上来的数据是否是上传表单的数据 
      if (!ServletFileUpload.isMultipartContent(request)) { 
       //按照传统方式获取数据 
       return; 
      } 
     
      //设置上传单个文件的大小的最大值,目前是设置为1024*1024字节,也就是1MB 
      //upload.setFileSizeMax(1024 * 1024); 
      //设置上传文件总量的最大值,最大值=同时上传的多个文件的大小的最大值的和,目前设置为10MB 
      upload.setSizeMax(1024 * 1024 * 10); 
     
      try { 
       //使用ServletFileUpload解析器解析上传数据,解析结果返回的是一个ListFileItem>集合,每一个FileItem对应一个Form表单的输入项 
       ListFileItem> items = upload.parseRequest(request); 
       IteratorFileItem> iterator = items.iterator(); 
       while (iterator.hasNext()) { 
        FileItem item = iterator.next(); 
     
        //判断jsp提交过来的是不是文件 
        if (item.isFormField()) { 
         errorMessage = "请提交文件!"; 
         break; 
        } else { 
         //文件名 
         String fileName = item.getName(); 
         if (fileName == null || fileName.trim() == "") { 
          System.out.println("文件名为空!"); 
         } 
         //处理不同浏览器提交的文件名带路径问题 
         fileName = fileName.substring(fileName.lastIndexOf("\\") + 1); 
         //文件大小 
         Long fileSize = item.getSize(); 
         //文件扩展名 
         String fileExtension = fileName.substring(fileName.lastIndexOf(".") + 1); 
         //判断扩展名是否合法 
         if (!validExtension(fileExtension)) { 
          errorMessage = "上传文件非法!"; 
          item.delete(); 
          break; 
         } 
         //获得文件输入流 
         InputStream in = item.getInputStream(); 
         //得到保存文件的名称 
         String saveFileName = createFileName(fileName); 
         //得到文件保存路径 
         String realFilePath = createRealFilePath(savePath, saveFileName); 
         //创建文件输出流 
         FileOutputStream out = new FileOutputStream(realFilePath); 
         //创建缓冲区 
         byte buffer[] = new byte[1024]; 
         int len = 0; 
         while ((len = in.read(buffer)) > 0) { 
          //写文件 
          out.write(buffer, 0, len); 
         } 
         //关闭输入流 
         in.close(); 
         //关闭输出流 
         out.close(); 
         //删除临时文件 
         item.delete(); 
         span style="color:#FF0000;">//将上传文件信息保存到附件表中 
         EntityAccessory entity = new EntityAccessory(); 
         entity.setFileName(fileName); 
         entity.setFileSize(fileSize); 
         entity.setFile_ext_name(fileExtension); 
         entity.setFilePath(realFilePath); 
         AccessoryDao.add(entity);/span> 
        } 
     
       } 
     
      } catch (FileUploadBase.FileSizeLimitExceededException e) { 
       e.printStackTrace(); 
       errorMessage = "单个文件超出最大值!!!"; 
      } catch (FileUploadBase.SizeLimitExceededException e) { 
       e.printStackTrace(); 
       errorMessage = "上传文件的总的大小超出限制的最大值!!!"; 
      } catch (FileUploadException e) { 
       e.printStackTrace(); 
       errorMessage = "文件上传失败!!!"; 
      } finally { 
       span style="color:#FF0000;">if (!"".equals(errorMessage)) { 
        request.setAttribute("errorMessage", errorMessage); 
        request.getRequestDispatcher("pages/upload/error.jsp").forward(request, response); 
       } else { 
        response.sendRedirect("listUploadedFiles"); 
       }/span> 
     
      } 
     
     } 
     
     @Override 
     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
      doGet(request, response); 
     } 
     
     private boolean validExtension(String fileExtension) { 
      String[] exts = {"jpg", "txt", "doc", "pdf"}; 
      for (int i = 0; i  exts.length; i++) { 
       if (fileExtension.equals(exts[i])) { 
        return true; 
       } 
     
      } 
     
      return false; 
     } 
     
     private String createFileName(String fileName) { 
      return UUID.randomUUID().toString() + "_" + fileName; 
     } 
     
     /** 
      * 根据基本路径和文件名称生成真实文件路径,基本路径\\年\\月\\fileName 
      * 
      * @param basePath 
      * @param fileName 
      * @return 
      */ 
     private String createRealFilePath(String basePath, String fileName) { 
      Calendar today = Calendar.getInstance(); 
      String year = String.valueOf(today.get(Calendar.YEAR)); 
      String month = String.valueOf(today.get(Calendar.MONTH) + 1); 
     
     
      String upPath = basePath + File.separator + year + File.separator + month + File.separator; 
      File uploadFolder = new File(upPath); 
      if (!uploadFolder.exists()) { 
       uploadFolder.mkdirs(); 
      } 
     
      String realFilePath = upPath + fileName; 
     
      return realFilePath; 
     } 
    } 
    

    测试效果截图 



    下集预告:实现附件删除功能!

    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脚本之家。

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    Jsp+Servlet实现文件上传下载 文件列表展示(二) Jsp+Servlet,实现,文件,上传下载,