第三周--疫情统计

这周主要是在完成以下这个题目

1、导入数据库：在导入数据库的过程中就遇到了问题；

 经过网上查询，把数据库里的“utf8mb4”全部改为“utf8”，再把utf8mb4_0900_ai_ci 替换为utf8_general_ci 。最后就可以成功导入了。

2、连接数据库

package util;

import java.sql.Connection;

import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class DBUtil {

    private static String URL="jdbc:mysql://localhost:3306/payiqing?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC";
    private static String username="root";
    private static String password="123";
    public static Connection getConnection() {
        Connection connection=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            connection=DriverManager.getConnection(URL, username, password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    public DBUtil() {
        // TODO Auto-generated constructor stub
    }

    public static String getData(String date) {
        JSONArray jsonArray=new JSONArray();
        Connection connection=getConnection();
        String sql="select distinct Province from info where Date like '"+date+"%'";
        String tempprovince="";
        ResultSet rs=null;
        try {
            Statement statement=connection.createStatement();   
            rs=statement.executeQuery(sql);
            while(rs.next())
                tempprovince+=rs.getString("Province")+";";
            rs.close();
            String str[]=tempprovince.split(";");
            for(int i=0;i<str.length;i++) {
                if(str[i].trim().equals(""))
                    continue;
                sql="select sum(Confirmed_num),sum(Yisi_num),sum(Cured_num),sum(Dead_num) from info where Date like '"+date+"%' and Province='"+str[i]+"'";
                rs=statement.executeQuery(sql);
                rs.next();
                JSONObject json=new JSONObject();
                json.put("name", str[i]);
                json.put("num", rs.getInt(1));
                json.put("yisi", rs.getString(2));
                json.put("cure", rs.getString(3));
                json.put("dead", rs.getString(4));
                rs.close();
                sql="select * from info where Date like '"+date+"%' and Province='"+str[i]+"'";
                rs=statement.executeQuery(sql);
                rs.next();
                json.put("code", rs.getString("Code"));
                rs.close();
                jsonArray.add(json);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return jsonArray.toString();
    }
    
    
}

servlet层

package Servlet;

import java.io.IOException;

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 MyDBUtil.*;

/**
 * Servlet implementation class getData
 */
@WebServlet("/getData")
public class getData extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public getData() {
        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);
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=UTF-8");
        response.getWriter().write(DBUtil.getData(request.getParameter("date")));
    }

}

实体类

package Dao;

public class Data {

    private String pri;
    private String confirmnum;
    
    public Data() {
        // TODO Auto-generated constructor stub
    }

    public String getPri() {
        return pri;
    }

    public void setPri(String pri) {
        this.pri = pri;
    }

    public String getConfirmnum() {
        return confirmnum;
    }

    public void setConfirmnum(String confirmnum) {
        this.confirmnum = confirmnum;
    }

}

3、页面布局。这里引用了在网上（https://www.echartsjs.com/zh/index.html）下载的柱形图的实例。

 <!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<link rel="stylesheet" href="layui/css/layui.css">
<script src="js/echarts.js"></script>
<script src="js/jquery.js"></script>
<title>疫情统计图</title>

<style>
            input[type=date]::-webkit-inner-spin-button { visibility: hidden; }
</style>
</head>
<body>
<input type="date" name="date"><button>查询</button>
<div id="main" style=" 100%;height:550px;overflow: auto;"></div>
    <script type="text/javascript">
    
        // 基于准备好的dom，初始化echarts实例
        var myChart = echarts.init(document.getElementById('main'));

        // 指定图表的配置项和数据
       

        //myChart.showLoading();
        
        var names=[];
        var nums=[];
        $("button").click(function(){
            $.post(
                'http://localhost:8080/yiqing2/getData',
                {"date":$("input[name=date]").val()},
                function(msg){
                    var json=JSON.parse(msg);
                    var size=json.length;
                    for(i=0;i<size;i++){
                        names.push(json[i].name);
                        nums.push(parseInt(json[i].num));
                    }
                
                    myChart.hideLoading();
                    var option = {
                            
                            title: {
                                text: $("input[name=date]").val()+'确诊人数'
                            },
                            tooltip: {},
                            legend: {
                                data:['确诊人数']
                            },
                            xAxis: {
                                data: names
                            },
                            yAxis: {
                                type:'value'
                            },
                            series: [{
                                name: '确诊人数',
                                type: 'bar',
                                data: nums
                            }]
                        };
                    myChart.setOption(option);
                    tr="<tr><th>省份</th><th>确诊人数</th><th>疑似人数</th><th>治愈人数</th><th>死亡人数</th></tr>";
                    $('.head').append(tr);
                    for(i=0;i<size;i++)
                        $('.main').append("<tr></tr>");
                    $('.main tr').each(function(i){
                        $(this).append("<td>"+json[i].name+"</td>");
                        $(this).append("<td>"+json[i].num+"</td>");
                        $(this).append("<td>"+json[i].yisi+"</td>");
                        $(this).append("<td>"+json[i].cure+"</td>");
                        $(this).append("<td>"+json[i].dead+"</td>");
                    })
                }
                
            )
        })
        
    </script>
    <table class="layui-table">
        <thead class="head">
            </thead>
        <tbody class="main"></tbody>
    </table>
</body>
</html>

最后运行结果如图：