简单中级项目Servlet/JSP实现web版windows资源管理器

java中级学完之后就可以自己写一些小项目，比如一些博客、商城。用到的技术也只是Servlet+JSP，练习才是最好的老师。下面介绍一个最简单的练手项目，模仿windows的文件管理，功能比较单一。就是输入地址http://localhost:8080/file/index会进入写好的首页，然后有C,E,F盘，点击每个磁盘会去读取磁盘下的文件展示在右边的空白处，显示的内容也是一个个超链接，可以继续点击，如果是文件夹继续展示，如果是文件就会进行下载。其中会进行日志记录，每一次点击操作（查看文件夹、下载文件）都会记录在数据库中。效果图如下，前台就是简单的JSP页面，一个主页面包含左右两个JSP。

项目目录结构如下图

整个实现流程是：首先输入http://localhost:8080/file/index网址进入IndexController直接转发到file.jsp页面，就是我们的首页。当继续点击C、E、F盘时，都是一个超链接

   <a href="file?act=c:/" target="body">系统保留(C:)</a> <br>

   点击后转到FileController进行处理，拿到请求参数act（也就是需要查询的盘符C：/），调用FileService类中的处理方法，判断该文件是目录还是文件，如果是目录就查出所有文件并返回，返回的是一个Map，key值放入文件名，value放入文件路径作为下次点击请求的act参数。如果是文件就进行下载。下面是每个类的源码：

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package gtja.controller;

import gtja.service.FileService;

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;

@WebServlet(urlPatterns = "/index")
public class IndexController extends HttpServlet {
    FileService fileService = new FileService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.getRequestDispatcher("jsp/file.jsp").forward(req,resp);
    }
}

package gtja.controller;


import gtja.service.FileService;

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.Map;

@WebServlet(urlPatterns = "/file")
public class FileController extends HttpServlet {

    FileService fileService = new FileService();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String act = req.getParameter("act");
        Map<String,String> fileList = fileService.queryFile(act,resp,req);
        req.setAttribute("fileList",fileList);
        //resp.sendRedirect("right.jsp");
        req.getRequestDispatcher("jsp/right.jsp").forward(req,resp);
    }
}

package gtja.service;

import gtja.util.MyUtil;
import gtja.vo.FileLog;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class FileService {
    static FileLog fileLog = new FileLog();
    //private static Logger logger = Logger.getLogger(FileService.class);
    public Map<String,String> queryFile(String act,HttpServletResponse resp,HttpServletRequest req) {
        Map<String,String> map = new HashMap<>();
        File file = new File(act);
        if(file.isDirectory()){
            File[] files = file.listFiles();
            for(int i = 0; i<files.length; i++){
                String str = files[i].toString();
                String key = str.substring(str.lastIndexOf("\\")+1);
                map.put(key,str.replace("\\","/"));
            }
            //日志记录
            myJDBC(req,"查看文件夹");

        }else{
            FileInputStream in = null;
            OutputStream out = null;
            try {
                resp.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(act, "UTF-8"));
                in = new FileInputStream(file);
                out = resp.getOutputStream();
            }catch (Exception e){
                e.printStackTrace();
            }
            byte[] buffer = new byte[1024];
            int len = 0;
            try {
                while((len=in.read(buffer))>0){
                    out.write(buffer,0,len);
                }
                in.close();
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

            myJDBC(req,"下载文件");

        }
        return map;
    }

    public static void myJDBC(HttpServletRequest req ,String a){
        fileLog.setIp(FileService.getIpAddress(req));
        fileLog.setAction(a);
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        fileLog.setTime(df.format(new Date()));
        String sql = "insert into db_log(ip,action,time) values(?,?,?) ";
        Connection conn = MyUtil.getConnection();
        PreparedStatement ps = null;
        try {
            ps= conn.prepareStatement(sql);
            ps.setString(1,fileLog.getIp());
            ps.setString(2,fileLog.getAction());
            ps.setString(3,fileLog.getTime());
            ps.execute();

        } catch (SQLException e) {
            e.printStackTrace();
        }
        MyUtil.closeResouce(conn);
    }

    public static String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }
}

package gtja.util;

import java.sql.*;

public class MyUtil {
	public static Connection getConnection(){
		Connection conn = null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "1874");
		} catch (Exception e) {
			e.printStackTrace();
		}
		return conn;
	} 
	
	public static void closeResouce(Connection conn){
		try {
			
			
			if(conn!=null){
				conn.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
	
	
	public static boolean isEmpty(String str){
		boolean flag = false;
		if(null==str||"".equals(str)){
			flag = true;
		}
		return flag;
	}
}

file.jsp

<%--
  Created by IntelliJ IDEA.
  User: gm
  Date: 2017/10/24
  Time: 9:19
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<html>
<head>
    <title>File Action</title>
    <style type="text/css">
        *{
            font-size:10pt;
        }
        body{
            text-align:center;
        }
        .table{
            width:1024px;
            height:100%;
            border:1px solid gray;/*固定边框,1像素*/
            border-collapse: collapse;/*单线的列表边框*/
        }
        .table td{
            border:1px solid gray;/*固定边框,1像素*/
        }
        iframe {
            width: 100%;
            height: 100%;
        }
    </style>
</head>
<body>


<table class="table" align="center">
    <tr>
        <td width="120" style="padding:5px;" align="center" valign="top">
            <iframe frameborder="0" scrolling="no" width="120" src="<c:url value='/jsp/left.jsp'/>" name="left"></iframe>
        </td>
        <td>
            <iframe frameborder="0" scrolling="no" src="<c:url value='/jsp/body.jsp'/>" name="body"></iframe>
        </td>
    </tr>
</table>
</body>
</html>

left.jsp

<%--
  Created by IntelliJ IDEA.
  User: gm
  Date: 2017/10/24
  Time: 14:37
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
    <base href="<%=basePath%>">
    <title>Title</title>
</head>
<body>
<div id="menu" style="background-color:#FFE4C4;height:1000px;width:150px;float:left;">
    <br>
    <a href="file?act=c:/" target="body">系统保留(C:)</a> <br>
    <br>
    <a href="file?act=e:/" target="body">新加卷(E:)</a> <br>
    <br>
    <a href="file?act=f:/" target="body">新加卷(F:)</a> <br>
</div>
</body>
</html>

body.jsp

<%--
  Created by IntelliJ IDEA.
  User: gm
  Date: 2017/10/24
  Time: 15:16
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <h2>请选择文件夹</h2>
</body>
</html>

right.jsp

<%--
  Created by IntelliJ IDEA.
  User: gm
  Date: 2017/10/24
  Time: 14:37
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
    <base href="<%=basePath%>">
    <title>Title</title>
</head>
<body>
<div id="content" style="background-color:#EEEEEE;height:1000px;width:950px;">
    <c:if test="${!empty fileList }">
        <c:forEach var="list" items="${fileList }" >

            <a href="file?act=${list.value}">${list.key}</a> <br>
        </c:forEach>
    </c:if>
</div>
</body>
</html>