Dapr Java HTTP call

Zhang_Xiang 2020-11-08 16:37:45
dapr java http


Version introduction

  • Java edition :8
  • Dapr Java SKD edition :0.9.2

Dapr Java-SDK HTTP Call document There is a prerequisite , The contents are as follows :

  • Dapr and Dapr CLI.
  • Java JDK 11 (or greater): Oracle JDK or OpenJDK.
  • Apache Maven version 3.x.

We see Java JDK The minimum requirement for version is 11, But this article shows what you use JDK 8, What is the reason for that , Sure Reference resources Java-SDK Issues,Issues The answer is as follows :

We want to validate that the SDK is built with Java 8 and apps can use it with Java 11.

It means they want to pass Java 11 Write application validation Java 8 Written SDK Whether it can be used normally . This article does not need to verify Java 11 Can you use Java-SDK , So this article will use Java 8 Building the application .

Engineering structure

3 Sub project , One client, Two service. Two new service The point is to show http Link call uses dapr How to achieve .3 All the projects are integrated Spring Boot.Spring Boot Automatically register after startup Controller、Config And so on. bean.

graph LR; java-client-a--1-->java-service-b; java-service-b--2-->java-service-c; java-service-c--3-->java-service-b; java-service-b--4-->java-client-a;
  1. java-client-a Call as client java-service-b;
  2. java-service-b Receiving request , And call java-service-c;
  3. java-service-c Receiving request , And respond to ;
  4. java-service-b received java-service-c The reply , And respond to java-client-a request .

java-service-c

java-service-c As http Call the end of the link , Just listen http The request can be .

package com.dapr.service;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.Options;
/**
* @author Zhang_Xiang
* @since 2020/11/7 10:51:22
*/
public class ServiceC {
/**
* Starts the service.
*
* @param args Expects the port: -p PORT
* @throws Exception If cannot start service.
*/
public static void main(String[] args) throws Exception {
Options options = new Options();
options.addRequiredOption("p", "port", true, "Port to listen to.");
CommandLineParser parser = new DefaultParser();
CommandLine cmd = parser.parse(options, args);
// If port string is not valid, it will throw an exception.
int port = Integer.parseInt(cmd.getOptionValue("port"));
DaprApplication.start(port);
}
}

DaprApplication.start(port); Integrate SpringBoot start-up .

package com.dapr.service;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
* Dapr's HTTP callback implementation via SpringBoot.
* Scanning package io.dapr.springboot is required.
*
* @author zhangxiang
*/
@SpringBootApplication(scanBasePackages = {"com.dapr.service"})
public class DaprApplication {
/**
* Starts Dapr's callback in a given port.
*
* @param port Port to listen to.
*/
public static void start(int port) {
SpringApplication app = new SpringApplication(DaprApplication.class);
app.run(String.format("--server.port=%d", port));
}
}

Start command :

dapr run --app-id java-service-c --app-port 9100 --dapr-http-port 3510 -- java -jar target/dapr-java-service-exec.jar com.dapr.service.ServiceC -p 9100

java-service-b

java-service-b You need to configure a DaprClient Bean, To use... When needed Http Injection of client places .

package com.dapr.service.config;
import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
* @author Zhang_Xiang
* @since 2020/11/8 08:46:49
*/
@Configuration
public class Client {
@Bean
public DaprClient getClient(){
return (new DaprClientBuilder()).build();
}
}

Next, what you need to call Controller Add constructor injection to .


/**
* SpringBoot Controller to handle input binding.
*
* @author zhangxiang
*/
@RestController
public class HelloController {
private final DaprClient client;
...
public HelloController(DaprClient client) {
this.client = client;
}
...
}

launch http request .

...
byte[] response = client.invokeService(SERVICE_APP_ID, "say", message, HttpExtension.POST, null,
byte[].class).block();
if (response != null) {
...
}
...

Start command :

dapr run --app-id java-service-b --app-port 9101 --dapr-http-port 3511 -- java -jar target/dapr-java-service-exec.jar com.dapr.service.ServiceB -p 9101

java-client-a

about java-client-a Come on , Integrate Springboot Optional. , Here, construct a every 5 Second, the client that initiated a request .

package com.dapr.client;
import com.alibaba.fastjson.JSON;
import com.common.ResponseResult;
import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
import io.dapr.client.domain.HttpExtension;
import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;
/**
* @author Zhang_Xiang
* @since 2020/11/7 17:30:26
*/
public class ClientA {
/**
* Identifier in Dapr for the service this client will invoke.
*/
private static final String SERVICE_APP_ID = "java-service-b";
/**
* Format to output date and time.
*/
private static final DateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
/**
* Starts the invoke client.
*
* @param args Messages to be sent as request for the invoke API.
*/
public static void main(String[] args) throws IOException {
try (DaprClient client = (new DaprClientBuilder()).build()) {
while (true) {
Calendar utcNow = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
String utcNowAsString = DATE_FORMAT.format(utcNow.getTime());
String msg = String.format("%s:this this java client A", utcNowAsString);
byte[] response = client.invokeService(SERVICE_APP_ID, "say", msg.getBytes(), HttpExtension.POST, null,
byte[].class).block();
if (response != null) {
String responseResultStr = new String(response);
ResponseResult responseResult = JSON.parseObject(responseResultStr, ResponseResult.class);
System.out.println(responseResult.getMessage());
}
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}

Start command :

dapr run --app-id java-client-a --dapr-http-port 3006 -- java -jar target/dapr-java-client-exec.jar com.dapr.client.ClientA

summary

The starting sequence of each module shall be :

graph LR; java-service-c-->java-service-b; java-service-b-->java-client-a;

The reason why the order is limited here is , If you start first java-client-a ,java-client-a It will pass immediately dapr Start to initiate a request to java-service-b , And then java-service-b Didn't start . This will trigger dapr The retry mechanism of .

retry

Service calls when event call fails and transient errors , The interval between the execution and the backoff time is (backoff time periods) Automatic retry of .
Error causing retry :

  • Network error , Including terminal unavailable and denial of connection .
  • Authentication error , Because on caller / Of the callee dapr The side car certificate update results in .

Every time you try again, you will 1 The time of seconds is interval , The maximum number of retries is 3 Time . And the destination side car passes through gRPC Establishing a connection 5 Second timeout .

java-client-a Print :

== APP == This is java-service-b,receive the message:2020-11-08 14:21:14.336:this this java client A,and request java-service-c get the response:{"message":"This is java-service-c,receive the message:\"2020-11-08 14:21:14.336:this this java client A\""}

java-service-b Print :

== APP == This is java-service-b,receive the message:2020-11-08 14:21:44.454:this this java client A

java-service-c Print :

== APP == This is java-service-c,receive the message:"2020-11-08 14:22:19.571:this this java client A"

Open a new command line window , Input dapr list

Start example

Source code address :https://github.com/ZhangX-Byte/dapr-java

Cloning of warehouse

git clone https://github.com/ZhangX-Byte/dapr-java.git
cd dapr-java

structure dapr-java project

mvn install

Then each project is install It will start up normally .

版权声明
本文为[Zhang_Xiang]所创,转载请带上原文链接,感谢

  1. [front end -- JavaScript] knowledge point (IV) -- memory leakage in the project (I)
  2. This mechanism in JS
  3. Vue 3.0 source code learning 1 --- rendering process of components
  4. Learning the realization of canvas and simple drawing
  5. gin里获取http请求过来的参数
  6. vue3的新特性
  7. Get the parameters from HTTP request in gin
  8. New features of vue3
  9. vue-cli 引入腾讯地图(最新 api,rocketmq原理面试
  10. Vue 学习笔记(3,免费Java高级工程师学习资源
  11. Vue 学习笔记(2,Java编程视频教程
  12. Vue cli introduces Tencent maps (the latest API, rocketmq)
  13. Vue learning notes (3, free Java senior engineer learning resources)
  14. Vue learning notes (2, Java programming video tutorial)
  15. 【Vue】—props属性
  16. 【Vue】—创建组件
  17. [Vue] - props attribute
  18. [Vue] - create component
  19. 浅谈vue响应式原理及发布订阅模式和观察者模式
  20. On Vue responsive principle, publish subscribe mode and observer mode
  21. 浅谈vue响应式原理及发布订阅模式和观察者模式
  22. On Vue responsive principle, publish subscribe mode and observer mode
  23. Xiaobai can understand it. It only takes 4 steps to solve the problem of Vue keep alive cache component
  24. Publish, subscribe and observer of design patterns
  25. Summary of common content added in ES6 + (II)
  26. No.8 Vue element admin learning (III) vuex learning and login method analysis
  27. Write a mini webpack project construction tool
  28. Shopping cart (front-end static page preparation)
  29. Introduction to the fluent platform
  30. Webpack5 cache
  31. The difference between drop-down box select option and datalist
  32. CSS review (III)
  33. Node.js学习笔记【七】
  34. Node.js learning notes [VII]
  35. Vue Router根据后台数据加载不同的组件(思考->实现->不止于实现)
  36. Vue router loads different components according to background data (thinking - & gt; Implementation - & gt; (more than implementation)
  37. 【JQuery框架,Java编程教程视频下载
  38. [jQuery framework, Java programming tutorial video download
  39. Vue Router根据后台数据加载不同的组件(思考->实现->不止于实现)
  40. Vue router loads different components according to background data (thinking - & gt; Implementation - & gt; (more than implementation)
  41. 【Vue,阿里P8大佬亲自教你
  42. 【Vue基础知识总结 5,字节跳动算法工程师面试经验
  43. [Vue, Ali P8 teaches you personally
  44. [Vue basic knowledge summary 5. Interview experience of byte beating Algorithm Engineer
  45. 【问题记录】- 谷歌浏览器 Html生成PDF
  46. [problem record] - PDF generated by Google browser HTML
  47. 【问题记录】- 谷歌浏览器 Html生成PDF
  48. [problem record] - PDF generated by Google browser HTML
  49. 【JavaScript】查漏补缺 —数组中reduce()方法
  50. [JavaScript] leak checking and defect filling - reduce() method in array
  51. 【重识 HTML (3),350道Java面试真题分享
  52. 【重识 HTML (2),Java并发编程必会的多线程你竟然还不会
  53. 【重识 HTML (1),二本Java小菜鸟4面字节跳动被秒成渣渣
  54. [re recognize HTML (3) and share 350 real Java interview questions
  55. [re recognize HTML (2). Multithreading is a must for Java Concurrent Programming. How dare you not
  56. [re recognize HTML (1), two Java rookies' 4-sided bytes beat and become slag in seconds
  57. 【重识 HTML ,nginx面试题阿里
  58. 【重识 HTML (4),ELK原来这么简单
  59. [re recognize HTML, nginx interview questions]
  60. [re recognize HTML (4). Elk is so simple