用户管理系统界面添加图片

原始数据：

package com.view;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Loin
 */
@WebServlet("/Loin")
public class LoinServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public LoinServlet() {
        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
        //浏览器uft-8展示
        response.setContentType("text/html;charset=utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out=response.getWriter();
        //返回一个界面
//        out.println("你好");
        out.println("<h1>用户登录</h1>");
        out.println("<form action='/user/ControlServlet' method='post'>");
        out.println("id:<input type='text' name='id'></br>");
        out.println("密 码:<input type='password' name='password'></br>");
        out.println("<input type='submit' value='登录'></br>");
        out.println("</form>");
        String errInof=(String)request.getAttribute("err");
if(errInof!=null){
    out.println("<font color='red'>"+errInof+"</font>");
}
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        this.doGet(request,response);
    }

}

分页技术：

分页代码;

ManagerUser.java

package com.view;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ManagerUser
 */
@WebServlet("/ManagerUser")
public class ManagerUser extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ManagerUser() {
        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.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        PrintWriter out=response.getWriter();
        out.print("<h1>管理用户</h1>欢迎登陆<a href='/user/ControlServlet'>返回主界面</a> <a href='/user/ControlServlet'>安全退出</a>");
        //从数据库中取出数据，并显示
        Connection conn = null;
        PreparedStatement ps = null;
        Statement stmt = null;
        ResultSet rs = null;
        //定义分页所需要的变量
        int pageNow=4;//当前页
        int pageSize=3;//每页3条记录
        int pageCount=1;
        int rowCount=1;
        //接收用户的pageNow
        String spageNow=request.getParameter("pageNow");
        if(spageNow!=null){
            pageNow=Integer.parseInt(spageNow);
        }

        try {// 加载驱动
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            System.out.println("建立连接失败");
        }

        try {// 创建连接对象
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/user", "root", "123456");
            stmt = conn.createStatement();// 创建sql操作对象
            //统计有多少行
            ps=conn.prepareStatement("select count(*) from user");
            rs=ps.executeQuery();
            rs.next();
            rowCount=rs.getInt(1);
            //算出有多少页
            pageCount=rowCount%pageSize==0? rowCount/pageSize:rowCount/pageSize+1;
            
            ps = conn.prepareStatement("select * from user where id<="+pageSize*pageNow+" and id>="+(pageSize*(pageNow-1)+1));
            // 赋值
            rs = ps.executeQuery();
            out.print("<table border=1px bordercolor=green cellspacing=0 width=500px>");//美观
            out.print("<tr><th>id</th><th>用户名</th><th>email</th><th>级别</th></tr>");
             while(rs.next()) {
                out.println("<tr><td>"+rs.getInt(1)+"</td><td>"+rs.getString(2)+"</td><td>"+rs.getString(3)+"</td><td>"+rs.getString(4)+"</td></tr>");
            } 
             out.print("</table>");
             //显示分页
             for(int i=1;i<=pageCount;i++){
                 out.print("<a href='/user/ManagerUser?pageNow="+i+"'><"       +i+"></a>  ");
             }
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("建立连接失败");
        } finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }

        }
        
        
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        this.doGet(request, response);
    }

}