使用HttpClient+Json解析器爬取数据并存入数据库

一、题目要求

说明：这里我只展示爬取数据的代码，将可视化结果与统计数据结合，实时显示当前最新数据只需将这篇博客代码和我那篇使用Echarts可视化数据库数据结合即可

二、思路

同学思路：我的大部分同学思路是使用HttpClient+Jsoup获取并解析目标页面的数据，然后调用Dao层中的方法将数据筛选并存入数据库中

我的思路：我直接使用了一个网上的一个最新疫情数据Json的目标网页，然后使用HttpClient获取该Json格式数据，然后使用Json解析器将

数据分离，然后调用Dao层中的方法将数据筛选并存入数据库中。

感想：个人感觉自己懒了一点，但感觉只要完成目的就可以了

三、源代码

Dao.java

package Dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import DBUtil.DBUtil;
import Test.Yione;

public class Dao {

    public boolean add(int id,String provinceName,String confirmeNum,String curesNum, String deathsNum )
       {
             Connection conn = DBUtil.getConn();
             PreparedStatement pstmt = null;
             boolean f = false;
             int a=0;
             try {
                 String sql = "insert into todaydata_copy1(id,provinceName,confirmeNum,curesNum,deathsNum value(?,?,?,?,?)";
                 pstmt = conn.prepareStatement(sql);
                 pstmt.setInt(1, id);
                 pstmt.setString(2, provinceName);
                 pstmt.setString(3, confirmeNum);
                 pstmt.setString(4, curesNum);
                 pstmt.setString(5, deathsNum );
                a = pstmt.executeUpdate();
             }
             catch(SQLException e) {
                 e.printStackTrace();
             }
             finally {
                 DBUtil.close(pstmt, conn);
             }
             if(a>0)
             f=true;

             return f;
       }

}

DBUtil.java（连接池代码，每个人的都有点不同）

package DBUtil;

import java.sql.*;

/**
 * 数据库连接工具
 * @author Hu
 *
 */
public class DBUtil {

    public static String url =  "jdbc:mysql://localhost:3306/yiqing?serverTimezone=UTC";
    public static String user = "root";
    public static String password = "123";

    public static Connection getConn () {
        Connection conn = null;

        try {
            Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动
            conn = DriverManager.getConnection(url, user, password);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return conn;
    }

    /**
     * 关闭连接
     * @param state
     * @param conn
     */
    public static void close (PreparedStatement preparedState, Connection conn) {
        if (preparedState != null) {
            try {
                preparedState.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void close (ResultSet rs, PreparedStatement preparedState, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (preparedState != null) {
            try {
                preparedState.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 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();
            }
        }
    }

    public static void main(String[] args) throws SQLException {
        Connection conn = getConn();
        PreparedStatement preparedStatement = null;
        ResultSet rs = null;
        String sql ="select * from testr";
        preparedStatement = conn.prepareStatement(sql);
        rs = preparedStatement.executeQuery();
        if(rs.next()){
            System.out.println("数据库为空");
        }
        else{
            System.out.println("数据库不为空");
        }
    }
}

Javabean部分代码

package Test;

public class Yione {
 private int id;
 private String provinceName;
 private String confirmeNum;
 private String curesNum;
 private String deathsNum;
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getProvinceName() {
    return provinceName;
}
public void setProvinceName(String provinceName) {
    this.provinceName = provinceName;
}
public String getConfirmeNum() {
    return confirmeNum;
}
public void setConfirmeNum(String confirmeNum) {
    this.confirmeNum = confirmeNum;
}
public String getCuresNum() {
    return curesNum;
}
public void setCuresNum(String curesNum) {
    this.curesNum = curesNum;
}
public String getDeathsNum() {
    return deathsNum;
}
public void setDeathsNum(String deathsNum) {
    this.deathsNum = deathsNum;
}

}

使用HttpClient获取该Json格式数据部分代码

package Test;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class getEntity {
    public static String get(){
        //创建客户端
        CloseableHttpClient httpClient = HttpClients.createDefault();

        String entityr = "";
        //创建Get实例
        HttpGet httpGet = new HttpGet("http://www.dzyong.top:3005/yiqing/province");

        //添加请求头的信息，模拟浏览器访问
        httpGet.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0");

        try{
            //获得Response
            CloseableHttpResponse response = httpClient.execute(httpGet);

            if(response.getStatusLine().getStatusCode() == 200){
                //当响应状态码为200时，获得该网页源码并打印
                String entity = EntityUtils.toString(response.getEntity(),"utf-8");
                entityr = entity;
            }

        }catch(Exception e){
            e.printStackTrace();
        }
        return entityr;
    }

}

解析数据并存入数据库的主函数代码

package Test;

import java.util.List;
import com.alibaba.fastjson.JSON;

import Dao.Dao;

public class Demo {

    public static void main(String[] args){
        Dao dao=new Dao();
        String str = getEntity.get();
        int index=str.indexOf("[");
        int index2=str.indexOf("]");
        String str1 = str.substring(index-1,index2+1);
        //字符串序列化成集合
        List<Yione> list= JSON.parseArray(str1,Yione.class);
        for(Yione item: list){
            System.out.println(item.getId() );
            System.out.println(item.getProvinceName());
            System.out.println(item.getConfirmeNum());
            System.out.println(item.getCuresNum());
            System.out.println(item.getDeathsNum());
           dao.add(item.getId(),item.getProvinceName(),item.getConfirmeNum(),item.getCuresNum(),item.getDeathsNum());
        }
    }
}

四、效果展示

由于这个最后效果只是一个写满数据的数据表，就不展示了

五、时间展示

原文地址：https://www.cnblogs.com/yang2000/p/12507667.html