Java8并行http请求加快访问速度

package cn.chinotan.dto;

/**
 * @program: test
 * @description: 位置
 * @author: xingcheng
 * @create: 2018-11-17 19:36
 **/
public class Location {

    String name;
    
    public Location() {
    }

    public Location(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package cn.chinotan.controller;

import cn.chinotan.dto.Location;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.List;

/**
 * @program: test
 * @description: 位置服务
 * @author: xingcheng
 * @create: 2018-11-17 19:42
 **/
@RestController
public class LocationController {

    @GetMapping("/location")
    public List<Location> getLocations() {
        List<Location> locations = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            locations.add(new Location(StringUtils.join("London", i)));
        }

        return locations;
    }

}

package cn.chinotan.dto;

/**
 * @program: test
 * @description: 温度
 * @author: xingcheng
 * @create: 2018-11-17 19:35
 **/
public class Temperature {

    private Double temperature;
    
    private String scale;

    public Double getTemperature() {
        return temperature;
    }

    public void setTemperature(Double temperature) {
        this.temperature = temperature;
    }

    public String getScale() {
        return scale;
    }

    public void setScale(String scale) {
        this.scale = scale;
    }
}

package cn.chinotan.controller;

import cn.chinotan.dto.Temperature;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.Random;

/**
 * @program: test
 * @description: 温度服务
 * @author: xingcheng
 * @create: 2018-11-17 19:45
 **/
@RestController
public class TemperatureController {

    @GetMapping("/temperature/{city}")
    public Temperature getAverageTemperature(@PathVariable("city") String city) {
        Temperature temperature = new Temperature();
        temperature.setTemperature((double) (new Random().nextInt(20) + 30));
        temperature.setScale("Celsius");
        try {
            Thread.sleep(500);
        } catch (InterruptedException ignored) {
        }
        return temperature;
    }

}

package cn.chinotan.dto;

/**
 * @program: test
 * @description: 天气预报
 * @author: xingcheng
 * @create: 2018-11-17 19:37
 **/
public class Forecast implements Comparable<Forecast> {

    private Location location;

    private Temperature temperature;
    
    public Forecast(Location location) {
        this.location = location;
    }

    public Forecast setTemperature(final Temperature temperature) {
        this.temperature = temperature;
        return this;
    }

    public Location getLocation() {
        return location;
    }

    public void setLocation(Location location) {
        this.location = location;
    }

    public Temperature getTemperature() {
        return temperature;
    }

    @Override
    public int compareTo(Forecast o) {
        if (o.getTemperature().getTemperature() > temperature.getTemperature()) {
            return 1;
        } else {
            return -1;
        }
    }
}

package cn.chinotan.dto.response;

import cn.chinotan.dto.Forecast;

import java.util.ArrayList;
import java.util.List;

/**
 * @program: test
 * @description: 服务响应
 * @author: xingcheng
 * @create: 2018-11-17 19:39
 **/
public class ServiceResponse {

    private long processingTime;

    private List<Forecast> forecasts = new ArrayList<>();

    public void setProcessingTime(long processingTime) {
        this.processingTime = processingTime;
    }

    public ServiceResponse forecasts(List<Forecast> forecasts) {
        this.forecasts = forecasts;
        return this;
    }

    public long getProcessingTime() {
        return processingTime;
    }

    public List<Forecast> getForecasts() {
        return forecasts;
    }

    public void setForecasts(List<Forecast> forecasts) {
        this.forecasts = forecasts;
    }
}

package cn.chinotan.controller;

import cn.chinotan.dto.Forecast;
import cn.chinotan.dto.Location;
import cn.chinotan.dto.Temperature;
import cn.chinotan.dto.response.ServiceResponse;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpMethod;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import rx.Observable;

import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @program: test
 * @description: 天气预报
 * @author: xingcheng
 * @create: 2018-11-17 19:47
 **/
@RestController
public class ForecastController {

    @Autowired
    RestTemplate restTemplate;

    private final static String SERVER_ADDRESS = "http://localhost:9000";

    @GetMapping("/v1/forecast")
    public ServiceResponse getLocationsWithTemperatureV1() {
        long startTime = System.currentTimeMillis();

        ServiceResponse response = new ServiceResponse();
        List<Location> locations = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/location"), HttpMethod.GET,
                HttpEntity.EMPTY, new ParameterizedTypeReference<List<Location>>() {
                }).getBody();
        locations.forEach(location -> {
            Temperature temperature = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/temperature/", location.getName()),
                    HttpMethod.GET, HttpEntity.EMPTY, Temperature.class).getBody();
            response.getForecasts().add(new Forecast(location).setTemperature(temperature));
        });

        long endTime = System.currentTimeMillis();
        response.setProcessingTime(endTime - startTime);
        return response;
    }

    @GetMapping("/v2/forecast")
    public ServiceResponse getLocationsWithTemperatureV2() {
        long startTime = System.currentTimeMillis();

        ServiceResponse response = new ServiceResponse();
        List<Location> locations = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/location"), HttpMethod.GET,
                HttpEntity.EMPTY, new ParameterizedTypeReference<List<Location>>() {
                }).getBody();
        List<Forecast> collect = locations.parallelStream().map(location -> {
            Temperature temperature = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/temperature/", location.getName()),
                    HttpMethod.GET, HttpEntity.EMPTY, Temperature.class).getBody();
            return new Forecast(location).setTemperature(temperature);
        }).collect(Collectors.toList());
        long sortStart = System.currentTimeMillis();
        List<Forecast> collectResponse = collect.parallelStream().sorted().collect(Collectors.toList());
        long sortEnd = System.currentTimeMillis();
        System.out.println("排序花费时间：" + (sortEnd - sortStart));
        response.setForecasts(collectResponse);
        
        long endTime = System.currentTimeMillis();
        response.setProcessingTime(endTime - startTime);
        return response;
    }

    @GetMapping("/v3/forecast")
    public ServiceResponse getLocationsWithTemperatureV3() {
        long startTime = System.currentTimeMillis();

        ServiceResponse response = new ServiceResponse();
        List<Location> locations = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/location"), HttpMethod.GET,
                HttpEntity.EMPTY, new ParameterizedTypeReference<List<Location>>() {
                }).getBody();
        locations.parallelStream().forEachOrdered(location -> {
            Temperature temperature = restTemplate.exchange(StringUtils.join(SERVER_ADDRESS, "/temperature/", location.getName()),
                    HttpMethod.GET, HttpEntity.EMPTY, Temperature.class).getBody();
            response.getForecasts().add(new Forecast(location).setTemperature(temperature));
        });

        long endTime = System.currentTimeMillis();
        response.setProcessingTime(endTime - startTime);
        return response;
    }

}

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9);
numbers.parallelStream()
       .forEach(out::println);

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9);
numbers.parallelStream()
       .forEachOrdered(out::println);