动态网页从数据库取信息,然后展示。

动态网页从数据库取信息,然后展示。_第1张图片

动态网页从数据库取信息,然后展示。_第2张图片

把数据库的驱动放在bin目录下。

通过servlet 读取数据库的内容,生成session,然后跨页面传给展示页。

package src;


import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
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 aaa
 */
@WebServlet("/aaa")
public class aaa extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public aaa() {
        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());
		
		 //1.导入jar包
        //2.注册驱动
        //Class.forName("com.mysql.jdbc.Driver");
        try {
			Class.forName("com.mysql.cj.jdbc.Driver");
		} catch (ClassNotFoundException e2) {
			// TODO Auto-generated catch block
			e2.printStackTrace();
		}

        //3.获取连接
        Connection con = null;
		try {
			con = DriverManager.getConnection("jdbc:mysql://mysql.sqlpub.com:3306/huangjin","laocooon","fc12f7a5215e8e0a_");
		} catch (SQLException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}

        //4.获取执行者对象
        Statement stat = null;
		try {
			stat = con.createStatement();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

        //5.执行sql语句,并且接收结果
        String sql = "SELECT * FROM MonthlySorted";
        ResultSet rs = null;
		try {
			rs = stat.executeQuery(sql);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

        //6.处理结果
        String i1="",i2="",i3="";

        try {
			while(rs.next()) {
			    i1+="'"+rs.getString(1)+"',";
			    i2+="'"+rs.getString(2)+"',";
			    i3+="'"+rs.getString(3)+"',";
			    
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        i1=i1.substring(0,i1.length()-1);//去掉最后一个逗号
        i2=i2.substring(0,i2.length()-1);//去掉最后一个逗号
        i3=i3.substring(0,i3.length()-1);//去掉最后一个逗号
        request.getSession().setAttribute("i1", i1);
        request.getSession().setAttribute("i2", i2);
        request.getSession().setAttribute("i3", i3);
        //7.释放资源
        try {
			con.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        try {
			stat.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        try {
			con.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
        
        //PrintWriter out = response.getWriter();		
	    //out.println(request.getSession().getAttribute("i1"));
	    //out.println(request.getSession().getAttribute("i2"));
	    //out.println(request.getSession().getAttribute("i3"));
        
	}

	/**
	 * @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);
	}

}

此页面作了两件事, 一就是通过   执行 aaa,获取数据,二是显示数据。

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>  
    <%
    String i1=(String)session.getAttribute("i1");
    String i2=(String)session.getAttribute("i2");
    String i3=(String)session.getAttribute("i3");
    %> 
   



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