reviews本来是一个使用gradle编译的war包，使用ibm的server进行服务的。而为了更方便的理解，我在网上找了一个使用spring boot和maven编写的服务，实现了同样的功能。

本项目的github地址：

https://github.com/aguncn/bookinfo-reviews

项目总体叙述

https://www.jianshu.com/p/cce33f54ed34

主要代码

package com.example.robreviews;

import com.fasterxml.jackson.databind.JsonNode;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.client.RestTemplate;

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

@SpringBootApplication
@Controller
public class RobReviewsApplication {

    public static void main(String[] args) {
        SpringApplication.run(RobReviewsApplication.class, args);
    }


    private final static Boolean ratingsEnabled = true;
    private final static String starColor = System.getenv("STAR_COLOR") == null ? "green" : System.getenv("STAR_COLOR");
    private final static String ratingsService = "http://localhost:8004/ratings";
    private static final String reviewText1 = System.getenv("REVIEW_TEXT_1") == null ? "This play was especially awesome because of its many references to Spring Boot" : System.getenv("REVIEW_TEXT_1");
    private static final String reviewText2 = System.getenv("REVIEW_TEXT_2") == null ? "I personally would have rewritten this play in Rust/Kotlin" : System.getenv("REVIEW_TEXT_2");


    private RestTemplate ratingsTemplate = new RestTemplate();

    class Rating {
        private int stars;
        private String color;

        public int getStars() {
            return stars;
        }

        public void setStars(int stars) {
            this.stars = stars;
        }

        public String getColor() {
            return color;
        }

        public void setColor(String color) {
            this.color = color;
        }
    }

    class ReviewEntry {
        private String reviewer;
        private String text;
        private Rating rating;

        public String getReviewer() {
            return reviewer;
        }

        public void setReviewer(String reviewer) {
            this.reviewer = reviewer;
        }

        public String getText() {
            return text;
        }

        public void setText(String text) {
            this.text = text;
        }

        public Rating getRating() {
            return rating;
        }

        public void setRating(Rating rating) {
            this.rating = rating;
        }
    }


    class Review {
        private String productId;
        private List<ReviewEntry> reviews;

        public String getProductId() {
            return productId;
        }

        public void setProductId(String productId) {
            this.productId = productId;
        }

        public List<ReviewEntry> getReviews() {
            return reviews;
        }

        public void setReviews(List<ReviewEntry> reviews) {
            this.reviews = reviews;
        }
    }

    static class RatingsResponse{

        private Map<String, String> ratings;

        public Map<String, String> getRatings() {
            return ratings;
        }

        public void setRatings(Map<String, String> ratings) {
            this.ratings = ratings;
        }
    }


    @GetMapping(value = "/reviews/{productId}", produces = "application/json")
    public ResponseEntity<Review> getReviews(@PathVariable("productId") String productId,
                                               @RequestHeader("end-user") @Nullable String user,
                                               @RequestHeader("user-agent") @Nullable String useragent,
                                               @RequestHeader("x-request-id") @Nullable String xreq,
                                               @RequestHeader("x-b3-traceid") @Nullable String xtraceid,
                                               @RequestHeader("x-b3-spanid") @Nullable String xspanid,
                                               @RequestHeader("x-b3-parentspanid") @Nullable String xparentspanid,
                                               @RequestHeader("x-b3-sampled") @Nullable String xsampled,
                                               @RequestHeader("x-b3-flags") @Nullable String xflags,
                                               @RequestHeader("x-ot-span-context") @Nullable String xotspan){

        int stars1 = -1;
        int stars2 = -1;



        if(ratingsEnabled) {
            try{
                HttpHeaders headers = new HttpHeaders();
                if(xreq!=null) {
                    headers.set("x-request-id",xreq);
                }
                if(xtraceid!=null) {
                    headers.set("x-b3-traceid",xtraceid);
                }
                if(xspanid!=null) {
                    headers.set("x-b3-spanid",xspanid);
                }
                if(xparentspanid!=null) {
                    headers.set("x-b3-parentspanid",xparentspanid);
                }
                if(xsampled!=null) {
                    headers.set("x-b3-sampled",xsampled);
                }
                if(xflags!=null) {
                    headers.set("x-b3-flags",xflags);
                }
                if(xotspan!=null) {
                    headers.set("x-ot-span-context",xotspan);
                }
                if(user!=null) {
                    headers.set("end-user", user);
                }
                if(useragent!=null) {
                    headers.set("user-agent", useragent);
                }

                HttpEntity<String> entity = new HttpEntity<>(headers);

                RatingsResponse resp = ratingsTemplate.exchange(ratingsService+"/"+productId, HttpMethod.GET, entity, RatingsResponse.class).getBody();
                stars1 = Integer.parseInt(resp.getRatings().get("Reviewer1"));
                stars2 = Integer.parseInt(resp.getRatings().get("Reviewer2"));
            }
            catch(Exception ex) {
                ex.printStackTrace();
            }
        }

        ReviewEntry re1 = new ReviewEntry();
        if(stars1 > 1){
            Rating r1 = new Rating();
            r1.setColor(starColor);
            r1.setStars(stars1);
            re1.setRating(r1);
        }
        re1.setReviewer("Reviewer1");
        re1.setText(reviewText1);

        ReviewEntry re2 = new ReviewEntry();
        if(stars2 > 1){
            Rating r2 = new Rating();
            r2.setColor(starColor);
            r2.setStars(stars2);
            re2.setRating(r2);
        }
        re2.setReviewer("Reviewer2");
        re2.setText(reviewText2);

        List<ReviewEntry> res = new ArrayList<>();
        res.add(re1);
        res.add(re2);

        Review ret = new Review();
        ret.setProductId(productId);
        ret.setReviews(res);

        return ResponseEntity.ok(ret);
    }
}

启动命令

java -Dserver.port=8003 -jar rob-reviews-1.0.jar

当前效果

可以看到，比之前的网页效果，又多了reviews右边的内容，下一次，我们再加上最后一个ratings打星服务吧。

2021-02-02 21_55_43-悬浮球.png