公文流转系统

首先把不同用户登录显示不同界面的功能实现

建立useradmin数据库表如下

 数据库连接util类

package com.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 数据库连接工具
 * @author 李泽宇
 *
 */
public class Butil {
    //联结字符串                                              //数据库名test
    public static String db_url = "jdbc:mysql://localhost:3306/sys?&useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
    //数据库用户名
    public static String db_user = "root";
    //数据库密码名
    public static String db_pass = "123456";
    
    public static Connection getConn () {
        
        //声明与数据库的连接并实例化为null
        Connection conn = null;
        
        try {
            //驱动程序名
            Class.forName("com.mysql.jdbc.Driver");//连接数据库
            //具体地连接到数据库——联接字符串（数据库名），联接用户名，联接密码名
            conn = DriverManager.getConnection(db_url, db_user, db_pass);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return conn;
    }
    
    /**
     * 关闭连接
     * @param state
     * @param conn
     */
    public static void close (Statement state, Connection conn) {
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void close (ResultSet rs, Statement state, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (state != null) {
            try {
                state.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

}

servlet类，利用id进行不同用户登录不同界面，登录失败重新回到登录界面

package com.servlet;

import java.io.IOException;
import java.sql.SQLException;

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.util.ArrayList;
import java.util.List;

import com.bean.Admin;
import com.dao.AdminDao;
import com.mysql.fabric.xmlrpc.base.Array;
/**
 * Servlet implementation class AdminServlet
 */
@WebServlet("/AdminServlet")
public class AdminServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AdminServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.getWriter().append("Served at: ").append(request.getContextPath());
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        String method=req.getParameter("method");
        System.out.println(method);
        if(method.equals("post"))
        {
            try {
                login(req,resp);
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                String msg = "登录信息错误";
                //把错误信息放入Request域中
                req.setAttribute("msg",msg);
                //请求转发到error.jsp页面
                req.getRequestDispatcher("/error.jsp").forward(req,resp);
            }
        }
    }
    protected void login(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException, SQLException {
        req.setCharacterEncoding("utf-8");
        String username=req.getParameter("username");
        String password=req.getParameter("password");
        System.out.println(username);
        System.out.println(password);
        Admin admin=new Admin();
        AdminDao admindao=new AdminDao();
        admin=admindao.login(username);
        System.out.println(admin.getPassword());
        if(password.equals(admin.getPassword()))
        {
            if("1".equals(admin.getId()))
            {
                req.getRequestDispatcher("/1-director.jsp").forward(req,resp);
            }
            else if("2".equals(admin.getId()))
            {
                req.getRequestDispatcher("/manage.jsp").forward(req,resp);
            }
            else if("12".equals(admin.getId()))
            {
                req.getRequestDispatcher("/2-assist1.jsp").forward(req,resp);
            }
            else if("13".equals(admin.getId()))
            {
                req.getRequestDispatcher("/3-assist2.jsp").forward(req,resp);
            }
            else if("14".equals(admin.getId()))
            {
                req.getRequestDispatcher("/4-assist3.jsp").forward(req,resp);
            }
            else if("15".equals(admin.getId()))
            {
                req.getRequestDispatcher("/5-office.jsp").forward(req,resp);
            }
            else if("21".equals(admin.getId()))
            {
                req.getRequestDispatcher("/6-product.jsp").forward(req,resp);
            }
            else if("31".equals(admin.getId()))
            {
                req.getRequestDispatcher("/7-sale.jsp").forward(req,resp);
            }
            else if("41".equals(admin.getId()))
            {
                req.getRequestDispatcher("/8-finance.jsp").forward(req,resp);
            }
        }
        else
        {
            req.getRequestDispatcher("/login.jsp").forward(req,resp);
        }
    }
}

jsp如下：