參考文獻： 當當開源文檔
上篇文章已經(jīng)創(chuàng)建了一個簡單的demo了。

REST的優(yōu)點：

• 可更高效利用緩存來提高響應(yīng)速度
• 通訊本身的無狀態(tài)性可以讓不同的服務(wù)器的處理一系列請求中的不同請求，提高服務(wù)器的擴展性
• 瀏覽器即可作為客戶端，簡化軟件需求
• 相對于其他疊加在HTTP協(xié)議之上的機制，REST的軟件依賴性更小
• 不需要額外的資源發(fā)現(xiàn)機制
• 在軟件技術(shù)演進中的長期的兼容性更好

使用場景：

• 跨語言調(diào)用： 前端WEB直接訪問服務(wù)
• 開放平臺API

• 企業(yè)內(nèi)部不同平臺調(diào)用

  
  
  一處編寫，到處調(diào)用

消費場景

• 非dubbo的消費端調(diào)用dubbo的REST服務(wù)（non-dubbo --> dubbo）
• dubbo消費端調(diào)用dubbo的REST服務(wù) （dubbo --> dubbo）
• dubbo的消費端調(diào)用非dubbo的REST服務(wù) （dubbo --> non-dubbo）

非dubbo消費端消費

創(chuàng)建SpringBoot工程，引入web依賴即可。這里使用了OKhttp3調(diào)用http請求所以依賴如下：

    <dependency>
        <groupId>com.zkdubbo</groupId>
        <artifactId>zk-dubbo-common</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>3.11.0</version>
    </dependency>

demo :

@RestController
@RequestMapping("/hello")
public class HelloController {

    @Value("${https.hello}")
    private String url;

    @GetMapping("/get")
    public DubboResponse get(){
        DubboResponse syncRequest = OKHttpUtils.getSyncRequest(url);
        return syncRequest;
    }

    @PostMapping("/post")
    public DubboResponse post(@RequestBody Object object){
        return OKHttpUtils.postSyncRequest(url, object);
    }
}

/**
 * @author bertram.wang
 * @sign 2019/7/7
 * @desc Http調(diào)用工具
 */
public class OKHttpUtils {

    private static final Logger LOGGER = LoggerFactory.getLogger(OKHttpUtils.class);
    private static final OkHttpClient HTTP_CLIENT = new OkHttpClient();
    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();

    /**
     * 同步的GET調(diào)用
     * @return
     */
    public static DubboResponse getSyncRequest(String url){
        LOGGER.info("GET 調(diào)用請求：{}", url);
        Request request = new Request.Builder().get().url(url).build();
        try {
            Response response = HTTP_CLIENT.newCall(request).execute();
            DubboResponse dubboResponse = OBJECT_MAPPER.readValue(response.body().bytes(), DubboResponse.class);
            return dubboResponse;
        } catch (IOException e) {
            LOGGER.error("GET 調(diào)用請求：{}異常， 原因： {}", url, e.getMessage());
            return DubboResponseBuild.fill(e.getMessage());
        }
    }

    /**
     * 同步的POST調(diào)用
     * @return
     */
    public static DubboResponse postSyncRequest(String url, Object data){
        LOGGER.info("POST 調(diào)用請求：{}", url);
        try {
            RequestBody requestBody = RequestBody.create(MediaType.parse("application/json;charset=UTF-8"), OBJECT_MAPPER.writeValueAsString(data));
            Request request = new Request.Builder().post(requestBody).url(url).build();
            Response response = HTTP_CLIENT.newCall(request).execute();
            DubboResponse dubboResponse = OBJECT_MAPPER.readValue(response.body().bytes(), DubboResponse.class);
            return dubboResponse;
        } catch (IOException e) {
            LOGGER.error("POST 調(diào)用請求：{}異常， 原因： {}", url, e.getMessage());
            return DubboResponseBuild.fill(e.getMessage());
        }
    }

}

server:
  port: 8880

https:
  hello: http://127.0.0.1:20880/servers/zkDubboServer/hello

非常簡單的一個消費demo。

消費者日志

服務(wù)提供者日志

服務(wù)提供者會發(fā)送MQ消息并消費。

@Override
public DubboResponse hello() {
    try {
        kafkaProducer.send("測試發(fā)送MQ");
    } catch (Exception e) {
        return DubboResponseBuild.fill(e.getMessage());
    }
    return DubboResponseBuild.success();
}

@Component
public class MyKafkaProducer<T> {

    @Resource
    private KafkaTemplate<String, T> kafkaTemplate;

    public void send(T message) throws Exception{
        kafkaTemplate.send("bertram.topic",  message);
    }

}
@Component
public class KafkaConsumer {

    @KafkaListener(topics = "bertram.topic")
    public void listen (ConsumerRecord<?, ?> record) throws Exception {
        System.out.printf("topic = %s, offset = %d, value = %s \n", record.topic(), record.offset(), record.value());
    }
}