60、Flink 的异步 IO 算子使用异步 Http 客户端查高德地图

1、概述

  Http 异步客户端
  设置：并行度=2，capacity=2，HttpMaxConn=2，client 为静态
  输入：同时发起4条查询
  输出：间隔10秒，同时返回4条数据

  JDBC 线程池+链接池
  设置：并行度=2，capacity=2，HttpMaxConn=2，client 为静态
  输入：同时发起4条查询
  输出：间隔10秒，先返回两条数据，间隔10秒，再返回两条数据

2、代码示例

package com.xu.flink.datastream.day11;

import org.apache.flink.streaming.api.datastream.AsyncDataStream;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.async.ResultFuture;
import org.apache.flink.streaming.api.functions.async.RichAsyncFunction;
import org.apache.flink.util.concurrent.Executors;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import org.apache.http.util.EntityUtils;

import java.util.Collections;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Future;
import java.util.function.Consumer;
import java.util.function.Supplier;
import java.util.concurrent.TimeUnit;

public class _06_HttpAsyncQueryGaoDe {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        env.setParallelism(2);

        DataStreamSource<String> lines = env.socketTextStream("localhost", 8888);

        AsyncDataStream.unorderedWait(lines, new AsyncHttpQueryFunction(), 20, TimeUnit.SECONDS, 2).print();

        env.execute();
    }
}

/**
 * Http 异步客户端
 * 设置：并行度=2，capacity=2，HttpMaxConn=2，client 为静态
 * 输入：同时发起4条查询
 * 输出：间隔10秒，同时返回4条数据
 * <p>
 * JDBC 线程池+链接池
 * 设置：并行度=2，capacity=2，HttpMaxConn=2，client 为静态
 * 输入：同时发起4条查询
 * 输出：间隔10秒，先返回两条数据，间隔10秒，再返回两条数据
 */
class AsyncHttpQueryFunction extends RichAsyncFunction<String, _06_OrderBean> {

    private static final String key = "***";
    private static CloseableHttpAsyncClient httpClient;

    @Override
    public void open(Configuration parameters) throws Exception {
        //创建异步 HttpClient 连接池，并初始化异步的 HttpClient
        RequestConfig requestConfig = RequestConfig.custom()
                .setSocketTimeout(3000)
                .setConnectTimeout(3000)
                .build();

        httpClient = HttpAsyncClients.custom()
                .setMaxConnTotal(2)
                .setDefaultRequestConfig(requestConfig)
                .build();

        System.out.println("open 方法被调用");
        System.out.println("httpClient=>" + httpClient.hashCode());

        httpClient.start();
    }

    @Override
    public void asyncInvoke(String line, ResultFuture<_06_OrderBean> resultFuture) throws Exception {

        try {
            // 1、解析JSON，获取经纬度信息
            _06_OrderBean orderBean = JSON.parseObject(line, _06_OrderBean.class);
            double longitude = orderBean.getLongitude();
            double latitude = orderBean.getLatitude();

            // 创建 httpGet 请求
            HttpGet httpGet = new HttpGet("https://restapi.amap.com/v3/geocode/regeo?&location=" + longitude + "," + latitude + "&key=" + key);

            // 2、通过 httpClient 提交异步请求，获取 future 对象
            // callback 是回调函数（也可通过回调函数拿结果）

            // 注意：此处使用 task 线程，如果此处是异步提交，则不会阻塞；如果此处是同步提交，则会阻塞；
            Future<HttpResponse> future = httpClient.execute(httpGet, null);

            // 3、从成功的 Future 中取数据，返回 orderBean
            // 使用 Executors.directExecutor() 获取返回结果

            // 注意：此处为异步获取返回结果，会使用单独的线程池，即使用 get() 方法，也不会阻塞 task 线程
            CompletableFuture.supplyAsync(new Supplier<_06_OrderBean>() {
                        @Override
                        public _06_OrderBean get() {
                            try {
                                HttpResponse response = future.get();

                                String province = null;
                                String city = null;
                                String district = null;


                                if (response.getStatusLine().getStatusCode() == 200) {
                                    //拿出响应的实例对象
                                    HttpEntity entity = response.getEntity();

                                    JSONObject jsonObject = JSON.parseObject(EntityUtils.toString(entity));

                                    JSONObject regeocodeObject = jsonObject.getJSONObject("regeocode");

                                    if (regeocodeObject != null && !regeocodeObject.isEmpty()) {
                                        JSONObject addObject = regeocodeObject.getJSONObject("addressComponent");
                                        district = addObject.getString("district");
                                        city = addObject.getString("city");
                                        province = addObject.getString("province");
                                    }
                                }
                                orderBean.setProvince(province);
                                orderBean.setCity(city);
                                orderBean.setDistrict(district);

                                return orderBean;
                            } catch (Exception e) {
                                return null;
                            }
                        }
                    }, Executors.directExecutor())
                    .thenAccept(new Consumer<_06_OrderBean>() {
                        @Override
                        public void accept(_06_OrderBean resultOrderBean) {
                            resultFuture.complete(Collections.singleton(resultOrderBean));
                        }
                    });

        } catch (Exception e) {
            resultFuture.complete(Collections.singleton(null));
        }
    }

    @Override
    public void timeout(String input, ResultFuture<_06_OrderBean> resultFuture) throws Exception {
        resultFuture.completeExceptionally(new RuntimeException(input + "=查询超时"));
    }

    @Override
    public void close() throws Exception {
        httpClient.close();
    }
}
-----------------------------------------------------------------
@Data
@NoArgsConstructor
@AllArgsConstructor
public class _06_OrderBean {
    private String oid;
    private String uid;
    private double money;
    private double longitude;
    private double latitude;
    private String province;
    private String city;
    private String district;

    @Override
    public String toString() {
        return "OrderBean{" +
                "oid='" + oid + '\'' +
                ", uid='" + uid + '\'' +
                ", money=" + money +
                ", longitude=" + longitude +
                ", latitude=" + latitude +
                ", province='" + province + '\'' +
                ", city='" + city + '\'' +
                ", district='" + district + '\'' +
                '}';
    }
}

3、测试用例

{"oid":"o001","uid":"u001","money":99.99,"longitude":115.690417, "latitude":36.239344}