全球疫情统计APP图表展示：
将该任务分解成三部分来逐个实现：
①爬取全球的疫情数据存储到云服务器的MySQL上
②在web项目里添加一个servlet，通过参数的传递得到对应的json数据
③设计AndroidAPP，通过时间和地名来访问服务器上的对应的servlet来获取json数据，然后将它与图表联系
第一步：由前面的web项目的积累，爬取全球的数据就很容易，利用Python爬虫爬取丁香医生上的数据，存储到服务器上的MySQL
from os import path
import requests
from bs4 import BeautifulSoup
import json
import pymysql
import numpy as np
import time
url = 'https://ncov.dxy.cn/ncovh5/view/pneumonia?from=timeline&isappinstalled=0' #请求地址
headers = {'user-agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36'}#创建头部信息
response = requests.get(url,headers = headers) #发送网络请求
#print(response.content.decode('utf-8'))#以字节流形式打印网页源码
content = response.content.decode('utf-8')
soup = BeautifulSoup(content, 'html.parser')
listB = soup.find_all(name='script',attrs={"id":"getListByCountryTypeService2true"})
world_messages = str(listB)[95:-21]
world_messages_json = json.loads(world_messages)
# print(listB)
# print(world_messages)
worldList = []
for k in range(len(world_messages_json)):
worldvalue = (world_messages_json[k].get('id'),time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(time.time())),
world_messages_json[k].get('continents'),world_messages_json[k].get('provinceName'),
world_messages_json[k].get('cityName'),world_messages_json[k].get('currentConfirmedCount'),
world_messages_json[k].get('suspectedCount'),world_messages_json[k].get('curedCount'),world_messages_json[k].get('deadCount'),world_messages_json[k].get('locationId'),
world_messages_json[k].get('countryShortCode'),)
worldList.append(worldvalue)
db = pymysql.connect("139.129.221.11", "root", "fengge666", "yiqing", charset='utf8')
cursor = db.cursor()
#sql_clean_world = "TRUNCATE TABLE world_map"
sql_world = "INSERT INTO world_map values (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)"
worldTuple = tuple(worldList)
#
# try:
# cursor.execute(sql_clean_world)
# db.commit()
# except:
# print('执行失败，进入回调1')
# db.rollback()
try:
cursor.executemany(sql_world,worldTuple)
db.commit()
except:
print('执行失败，进入回调3')
db.rollback()
db.close()
第二步：在之前的web项目里增加一个worldServlet来通过传递过来的参数（时间，地名）来获取服务器里数据库的信息，然后以json的数据格式返回。
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 com.google.gson.Gson;
import Bean.World;
import Dao.predao;
/**
* Servlet implementation class worldServlet
*/
@WebServlet("/worldServlet")
public class worldServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public worldServlet() {
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
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
response.setCharacterEncoding("utf-8");
String date=request.getParameter("date");
String name=request.getParameter("name");
//System.out.println("666:"+date+" "+name);
predao dao=new predao();
World bean=dao.findworld(date,name);
//if(bean==null)
// System.out.println("world为空");
Gson gson = new Gson();
String json = gson.toJson(bean);
response.getWriter().write(json);
//System.out.println(json);
}
/**
* @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);
}
}
第三步：Android端的设计，也要细分成两部分。第一部分设计界面的样式以及图表的展示，第二部分就是实现Android端访问远程服务器里的数据获取对应的信息，然后再配置到Android的图表里。
第一部分实现界面的设计，以及图表。
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/tv_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_marginTop="16dp"
android:text="时间"
android:textSize="25dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/et_time"
android:layout_width="250dp"
android:layout_height="46dp"
android:layout_marginEnd="100dp"
android:layout_marginRight="100dp"
android:gravity="center"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="@+id/tv_time" />
<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="99dp"
android:paddingTop="110dp"
android:text="国家名"
android:textSize="25dp"
app:layout_constraintBottom_toTopOf="@+id/chartshow_wb"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@+id/et_name"
android:layout_width="250dp"
android:layout_height="60dp"
android:gravity="center"
android:paddingLeft="120dp"
app:layout_constraintBottom_toBottomOf="@+id/bt_ly"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@+id/bt_ly"
app:layout_constraintTop_toTopOf="@+id/tv_time" />
<LinearLayout
android:id="@+id/bt_ly"
android:layout_width="409dp"
android:layout_height="209dp"
android:layout_marginTop="16dp"
android:gravity="center_horizontal"
android:paddingTop="150dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<Button
android:id="@+id/linechart_bt"
style="?android:attr/buttonStyleSmall"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="折线图" />
<Button
android:id="@+id/barchart_bt"
style="?android:attr/buttonStyleSmall"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="柱状图" />
<Button
android:id="@+id/piechart_bt"
style="?android:attr/buttonStyleSmall"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="饼状图" />
</LinearLayout>
<WebView
android:id="@+id/chartshow_wb"
android:layout_width="408dp"
android:layout_height="0dp"
android:layout_gravity="center"
android:layout_marginBottom="4dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/tv_name">
</WebView>
</androidx.constraintlayout.widget.ConstraintLayout>
界面有三部分组成：其一是时间选择框和地名选择，其二就是三个按钮（折线，柱状，圆饼），其三就是webview来展示我们的图表界面
图表的设计，首先要将echart.min.js放在AndroidStudio里的assets里，然后再放入自己的图表html代码，通过json数据来给图表进行赋值。同样在主页面对webview进行一堆设置，允许运行脚本，设置它的loadURL，然后设计三个按钮的点击方式，同时启动不同的脚本。
<!DOCTYPE html>
<!-- release v4.3.6, copyright 2014 - 2017 Kartik Visweswaran -->
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>Android使用Echarts示例</title>
</head>
<body>
<div id="main" style="width: 100%; height: 350px;"></div>
<script src="./echarts.min.js"></script>
<script type="text/javascript">
window.addEventListener("resize",function(){
option.chart.resize();
});
//初始化路径
var myChart;
// 通用属性定义
var options = {
title : {
text : "Echart测试"
},
tooltip : {
show : false
},
toolbox : {
show : false
},
};
function doCreatChart(type,jsondata){
// 基于准备好的dom，初始化echarts实例
var myChart = echarts.init(document.getElementById('main'));
if(type=='line'||type=='bar')
{
// 指定图表的配置项和数据
options = {
title: {
text: '人数'
},
tooltip: {},
legend: {
data:['疫情状况']
},
xAxis: {
data: ["确诊","疑似","治愈","死亡"]
},
yAxis: {},
series: [{
name: '患者数',
type: type,
data: jsondata
}]
};
}else{
options = {
series : [
{
type:type,
radius : '55%',
center: ['50%', '60%'],
data:[
{value:335, name:'确诊'},
{value:310, name:'疑似'},
{value:234, name:'治愈'},
{value:135, name:'死亡'}
]
}
]
};
}
// 使用刚指定的配置项和数据显示图表。
myChart.setOption(options);
}
</script>
</body>
</html>
第二部分就是通过Android端的http访问来获取服务器端的json数据，在将该数据传到图表的数据格式里。
MainActivity
package com.example.yiqing;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Calendar;
public class MainActivity extends Activity implements View.OnClickListener {
private EditText meditText,etname;
private Button linechart_bt,barchart_bt,piechart_bt;
private WebView chartshow_wb;
private String name;
private String data;
private world bean;
private String[] url;
private String[] json = {new String()};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
bean=new world();
}
private void getJson(final String address) {
new Thread(new Runnable(){
@Override
public void run() {
HttpURLConnection connection = null;
try {
URL url = new URL(address);
Log.d("address",address);
connection=(HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(10000);
connection.setReadTimeout(5000);
connection.connect();
int code=connection.getResponseCode();
if(code==200){
Log.i("accept:","链接成功");
InputStream is=connection.getInputStream();
String state = getStringFromInputStream(is);
JSONObject jsonObject = new JSONObject(state);
//String json=jsonObject.toString();
bean.setConfirmed(jsonObject.getString("confirmed"));
bean.setCured(jsonObject.getString("cured"));
bean.setDead(jsonObject.getString("dead"));
bean.setSuspected(jsonObject.getString("suspected"));
json[0] ="["+bean.getConfirmed()+","+bean.getSuspected()+","+bean.getCured()+","+bean.getDead()+"]";
//Log.i(etname.getText().toString(),json[0]);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
if(connection!=null){
connection.disconnect();
}
}
}
}).start();
}
private static String getStringFromInputStream(InputStream is) throws Exception{
ByteArrayOutputStream baos=new ByteArrayOutputStream();
byte[] buff=new byte[1024];
int len=-1;
while((len=is.read(buff))!=-1){
baos.write(buff, 0, len);
}
is.close();
String html=baos.toString();
baos.close();
return html;
}
/**
* 初始化页面元素
*/
private void initView(){
linechart_bt=(Button)findViewById(R.id.linechart_bt);
barchart_bt=(Button)findViewById(R.id.barchart_bt);
piechart_bt=(Button)findViewById(R.id.piechart_bt);
etname=(EditText) findViewById(R.id.et_name);
meditText=(EditText) findViewById(R.id.et_time);
meditText.setOnClickListener(this);
linechart_bt.setOnClickListener(this);
barchart_bt.setOnClickListener(this);
piechart_bt.setOnClickListener(this);
chartshow_wb=(WebView)findViewById(R.id.chartshow_wb);
//进行webwiev的一堆设置
//开启本地文件读取（默认为true，不设置也可以）
chartshow_wb.getSettings().setAllowFileAccess(true);
//开启脚本支持
chartshow_wb.getSettings().setJavaScriptEnabled(true);
chartshow_wb.loadUrl("file:///android_asset/echarts.html");
name=etname.getText().toString().trim();
data=meditText.getText().toString().trim();
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.et_time:
Calendar calendar = Calendar.getInstance();
DatePickerDialog datePickerDialog=new DatePickerDialog(MainActivity.this, new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
if(month<10)
MainActivity.this.meditText.setText(year + "-" +"0"+(month+1) + "-" + dayOfMonth);
else
MainActivity.this.meditText.setText(year + "-" + (month+1) + "-" + dayOfMonth);
}
},calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH));
datePickerDialog.show();
break;
case R.id.linechart_bt:
url = new String[]{"http://139.129.221.11/yiqing/worldServlet?date="};
url[0] = url[0] + meditText.getText().toString()+"&name="+etname.getText().toString();
getJson(url[0]);
//Log.i("json:",json[0]);
//String json="["+bean.getConfirmed()+","+bean.getSuspected()+","+bean.getCured()+","+bean.getDead()+"]";
Log.i("jsonline:",json[0]);
chartshow_wb.loadUrl("javascript:doCreatChart('line',"+json[0]+");");
//Toast.makeText(MainActivity.this,"折线图",Toast.LENGTH_SHORT).show();
break;
case R.id.barchart_bt:
url = new String[]{"http://139.129.221.11/yiqing/worldServlet?date="};
url[0] = url[0] + meditText.getText().toString()+"&name="+etname.getText().toString();
getJson(url[0]);
chartshow_wb.loadUrl("javascript:doCreatChart('bar',"+json[0]+");");
break;
case R.id.piechart_bt:
url = new String[]{"http://139.129.221.11/yiqing/worldServlet?date="};
url[0] = url[0] + meditText.getText().toString()+"&name="+etname.getText().toString();
getJson(url[0]);
chartshow_wb.loadUrl("javascript:doCreatChart('pie',"+json[0]+");");
break;
default:
break;
}
}
}
制作中遇到的困难以及解决方案：
①远程数据库的连接无法访问，发现自己的服务器3306端口未开放同时要对服务器里的mysql里的一些东西进行配置：我参考的博客是-->远程连接数据库
②本来想的是进行jdbc访问远程数据库，奈何整了大半天硬是连不上，最终换了一种方式采取http访问服务器里的数据。
③安卓新版本默认不允许使用明文网络传输，
解决办法如下，在AndroidManifest.xml文件的<application标签中，加入一句"android:usesCleartextTraffic="true",允许应用进行明文传输即可。
或者采用：
更改 AndroidManifest 的 application 标签下的配置。
添加 networkSecurityConfig(网络安全配置)。
android:networkSecurityConfig="@xml/network_security_config"
network_security_config 文件内容如下：
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
<base-config cleartextTrafficPermitted="true" />
</network-security-config>
