关于云计算:springcloudsquare开发实战三种类型全覆盖

欢送拜访我的 GitHub

这里分类和汇总了欣宸的全副原创 (含配套源码)：https://github.com/zq2599/blog_demos

本篇概览

• 前文《五分钟搞懂 spring-cloud-square》具体介绍了什么是 spring-cloud-square，以及三种实现类型的具体概念，爱入手的您已急不可待想编码体验 spring-cloud-square 了，本篇咱们就来畅快实战，体验这个 spring 官网带给咱们的 smart client
• 如题目所述，接下里咱们会将 spring-cloud-square 提供的三种 client 都编码体验，总的来说本篇由以下内容形成：

1. 新建 maven 工程，名为 <font color=”blue”>spring-cloud-square-tutorials</font>，这是本篇所有利用的父工程，库版本在此工程中对立治理；
2. 创立子工程 <font color=”blue”>eureka</font>，作为注册核心
3. 创立子工程 <font color=”blue”>client</font>，放一些专用的数据结构
4. 创立子工程 <font color=”blue”>provider</font>，身份是服务提供者，接下来的三个用到 spring-cloud-square 的子工程，都调用 provider 的服务
5. 创立子工程 <font color=”blue”>consumer-okhttp</font>，基于 spring-cloud-square 的 <font color=”red”>okhttp</font> 能力做近程调用
6. 创立子工程 <font color=”blue”>consumer-retrofit-okhttp</font>，基于 spring-cloud-square 的 <font color=”red”>retrofit + okhttp</font> 能力做近程调用
7. 创立子工程 <font color=”blue”>consumer-retrofit-webflux</font>，基于 spring-cloud-square 的 <font color=”red”>retrofit + webflux</font> 能力做近程调用

• 上述几个服务的关系如下图：

如何验证

• 代码写完之后，如何验证性能是否合乎预期呢？本篇采纳单元测试的形式，consumer-okhttp、consumer-retrofit-okhttp、consumer-retrofit-webflux 这三个子工程都有本人的单元测试代码，执行通过就意味着代码性能合乎预期了

源码下载

• 本篇实战中的残缺源码可在 GitHub 下载到，地址和链接信息如下表所示 (https://github.com/zq2599/blo…)：

• 这个 git 我的项目中有多个文件夹，本篇的源码在 <font color=”blue”>spring-cloud-square-tutorials</font> 文件夹下，如下图红框所示：
  

版本信息

• 本篇实战波及到的次要版本状况如下：
• JDK：1.8.0_291
• IDEA：2021.1.3 (Ultimate Edition)
• maven：3.8.1
• 操作系统：win10 64 位
• springboot：2.4.4
• spring-cloud：2020.0.2
• spring-cloud-square：0.4.0-SNAPSHOT

父工程 spring-cloud-square-tutorials

• 父工程名为 <font color=”blue”>spring-cloud-square-tutorials</font>，其 pom.xml 如下，除了依赖库的版本在此对立治理，还要留神的是两个仓库的引入（https://repo.spring.io/snapshot 和 https://repo.spring.io/milestone），引入它们是因为 spring-cloud-square 还在孵化阶段，没有公布到 maven 地方仓库：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.bolingcavalry</groupId>
    <artifactId>spring-cloud-square-tutorials</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
        <spring-cloud.version>2020.0.2</spring-cloud.version>
        <square.dependency.version>0.4.0-SNAPSHOT</square.dependency.version>
    </properties>

    <packaging>pom</packaging>
    <description>Demo project for Spring Cloud Square Retrofit Web</description>

    <modules>
        <module>provider</module>
        <module>eureka</module>
        <module>consumer-okhttp</module>
        <module>client</module>
        <module>consumer-retrofit-okhttp</module>
        <module>consumer-retrofit-webflux</module>
    </modules>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <dependency>
                <groupId>com.squareup.okhttp3</groupId>
                <artifactId>okhttp</artifactId>
                <version>3.14.9</version>
                <scope>compile</scope>
            </dependency>

            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>1.1.7</version>
            </dependency>

            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.16.16</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-square-okhttp</artifactId>
                <version>${square.dependency.version}</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-square-retrofit</artifactId>
                <version>${square.dependency.version}</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-boot-starter-webflux</artifactId>
                <version>${square.dependency.version}</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-square-retrofit-webclient</artifactId>
                <version>${square.dependency.version}</version>
            </dependency>

        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <!--skip deploy (this is just a test module) -->
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </pluginRepository>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
    </pluginRepositories>
</project>

注册核心 eureka

• eureka 利用并没有什么特别之处，pom.xml 如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-cloud-square-tutorials</artifactId>
        <groupId>com.bolingcavalry</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka</artifactId>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <start-class>com.bolingcavalry.eureka.EurekaApplication</start-class>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
<!--                <version>Finchley.BUILD-SNAPSHOT</version>-->
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <!-- defined in spring-cloud-starter-parent pom (as documentation hint),
                    but needs to be repeated here -->
                <configuration>
                    <requiresUnpack>
                        <dependency>
                            <groupId>com.netflix.eureka</groupId>
                            <artifactId>eureka-core</artifactId>
                        </dependency>
                        <dependency>
                            <groupId>com.netflix.eureka</groupId>
                            <artifactId>eureka-client</artifactId>
                        </dependency>
                    </requiresUnpack>
                </configuration>
            </plugin>

            <plugin>
                <!--skip deploy (this is just a test module) -->
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

• 中规中矩的配置文件 application.yml，端口是 8761，前面的利用也要保持一致：

server:
  port: 8761

spring:
  application:
    name: eureka

eureka:
  client:
    registerWithEureka: false
    fetchRegistry: false
  server:
    waitTimeInMsWhenSyncEmpty: 0

• 启动类 EurekaApplication.java，记得用注解 EnableEurekaServer 开启 eureka 服务：

package com.bolingcavalry.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {public static void main(String[] args) throws Exception {SpringApplication.run(EurekaApplication.class, args);
    }
}

• eureka 利用曾经实现，接下来是服务提供者了

服务提供者 provider

• - 新建名为 <font color=”blue”>provider</font> 的利用，pom.xml 如下，可见是个一般的 web 工程，会将本人注册到 eureka 下来：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-cloud-square-tutorials</artifactId>
        <groupId>com.bolingcavalry</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>provider</artifactId>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.bolingcavalry</groupId>
            <artifactId>client</artifactId>
            <version>${project.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-context</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- 如果父工程不是 springboot，就要用以下形式应用插件，能力生成失常的 jar -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.bolingcavalry.provider.ProviderApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

• 配置文件 application.yml：

spring:
  application:
    name: provider

server:
  port: 18080

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

• 启动类 ProviderApplication .java：

package com.bolingcavalry.provider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

• web 服务类，可见对外提供了两个接口 <font color=”blue”>hello-str</font> 和 <font color=”blue”>hello-obj</font>，前者返回字符串，或者返回对象：

package com.bolingcavalry.provider.controller;

import com.bolingcavalry.client.HelloResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Random;

@RestController
public class Hello {

    public static final String HELLO_PREFIX = "Hello World";

    @Autowired
    DiscoveryClient client;

    /**
     * 随机取一个 provider 实例，返回其形容信息，* 如果只有一个 provider 实例时，返回的就是以后服务信息
     * @return
     */
    private String providerDescription() {List<ServiceInstance> instances = client.getInstances("provider");
        ServiceInstance selectedInstance = instances
                .get(new Random().nextInt(instances.size()));

        return String.format("serviceId [%s], host [%s], port [%d]",
                selectedInstance.getServiceId(),
                selectedInstance.getHost(),
                selectedInstance.getPort());
    }

    private String dateStr(){return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date());
    }

    @GetMapping("/hello-str")
    public String helloStr() {List<ServiceInstance> instances = client.getInstances("provider");
        ServiceInstance selectedInstance = instances
                .get(new Random().nextInt(instances.size()));
        return HELLO_PREFIX
                + ":"
                + providerDescription()
                + ","
                + dateStr();}
    
    @GetMapping("/hello-obj")
    public HelloResponse helloObj(@RequestParam("name") String name) {return new HelloResponse(name, dateStr(), providerDescription());
    }
}

• 这个 provider 利用算是个最朴实无华的 web 服务了

启动服务

• 当初能够将 eureka 和 provider 服务先后启动，这样前面的利用编码实现后能够间接测试

consumer-okhttp，基于 spring-cloud-square 的 okhttp 能力

• 接下来要创立的利用 <font color=”blue”>consumer-okhttp</font>，应用的是 spring-cloud-square 三种能力的第一种：okhttp
• pom.xml 内容如下，重点是 spring-cloud-square-okhttp 和 spring-cloud-starter-loadbalancer 这两个库的引入：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-cloud-square-tutorials</artifactId>
        <groupId>com.bolingcavalry</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>consumer-okhttp</artifactId>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>com.bolingcavalry</groupId>
            <artifactId>client</artifactId>
            <version>${project.version}</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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-square-okhttp</artifactId>
            <version>0.4.0-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- 如果父工程不是 springboot，就要用以下形式应用插件，能力生成失常的 jar -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.bolingcavalry.ConsumerApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

• 配置文件 application.yml，还是常见的那几个配置：利用名、端口、eureka：

spring:
  application:
    name: consumer-okhttp

server:
  port: 18081

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

• 启动类：

package com.bolingcavalry.consumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

• 接下来是重要的配置类 OkHttpClientConfig.java，用于实例化 OkHttpClient.Builder 对象并注册到 spring 环境：

package com.bolingcavalry.consumer;

import okhttp3.OkHttpClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
class OkHttpClientConfig{
    @Bean
    @LoadBalanced
    public OkHttpClient.Builder okHttpClientBuilder() {return new OkHttpClient.Builder();
    }
}

• 而后就能够应用这个 Builder 来创立 OkHttpClient 实例了，如下所示，可见入参 request 的 url 字段里应用了服务名 <font color=”blue”>provider</font>，相当于 OkHttpClient 内如也能通过服务名获得具体的服务地址，至于是如何获取的，会在前面的文章详细分析，整段代码除了 url 应用服务名，并没有什么值得关注的中央了，一般的 OkHttpClient 应用而已：

package com.bolingcavalry.consumer.controller;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.io.IOException;

@RestController
public class RemoteHello {
    @Autowired
    private OkHttpClient.Builder builder;

    @GetMapping("/remote-str")
    public String hello() throws IOException {
        // 间接应用服务名
        Request request = new Request.Builder().url("http://provider/hello-str").build();

        // 近程拜访
        Response response = builder.build().newCall(request).execute();

        return "get remote response :" + response.body().string();
    }
}

• 接下来看看单元测试代码，应用 MockMvcRequestBuilders 结构 http 申请，查看返回码和返回内容：

package com.bolingcavalry.consumer.controller;

import com.bolingcavalry.client.Constants;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import static org.hamcrest.Matchers.containsString;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@SpringBootTest
@AutoConfigureMockMvc
@Slf4j
class RemoteHelloTest {

    @Autowired
    private MockMvc mvc;

    @Test
    void hello() throws Exception {String responseString = mvc.perform(MockMvcRequestBuilders.get("/remote-str").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().string(containsString(Constants.HELLO_PREFIX)))
                .andDo(print())
                .andReturn()
                .getResponse()
                .getContentAsString();

        log.info("response in junit test :\n" + responseString);
    }
}

• 如果 eureka 和 provider 都运行起来了，那么此时能够间接运行单元测试类，顺利通过测试，如下图：

consumer-retrofit-okhttp，基于 spring-cloud-square 的 okhttp 能力

• 接下来的两个利用都应用了当下热门的 retrofit，再搭配 Spring Cloud LoadBalance 实现服务注册发现，当然了 retrofit 本身无奈实现网络申请解决，要依赖其余库，先看 okhttp 库的
• 新建利用 <font color=”blue”>consumer-retrofit-okhttp</font>，其 pom.xml 如下，要留神的必须依赖 spring-cloud-square-retrofit 和 spring-cloud-square-okhttp，另外，为了：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-cloud-square-tutorials</artifactId>
        <groupId>com.bolingcavalry</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>consumer-retrofit-okhttp</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.bolingcavalry</groupId>
            <artifactId>client</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-square-retrofit</artifactId>
            <version>0.4.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-square-okhttp</artifactId>
            <version>0.4.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <!--skip deploy (this is just a test module) -->
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

• 配置文件：

spring:
  application:
    name: consumer-retrofit-okhttp
server:
  port: 18082
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

• 启动类：

package com.bolingcavalry.consumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

• 配置类，和前一个利用的没啥区别，想想也是，底层可不都是 okhttp 么：

package com.bolingcavalry.consumer;

import okhttp3.OkHttpClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.square.retrofit.EnableRetrofitClients;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableRetrofitClients
class OkHttpClientConfig{
    @Bean
    @LoadBalanced
    public OkHttpClient.Builder okHttpClientBuilder() {return new OkHttpClient.Builder();
    }
}

• 接下来，乏味的局部呈现了，先定义 HelloService.java，外面的注解 RetrofitClient 指定了对应的服务名 <font color=”blue”>provider</font>，在 hello 办法生，用 GET 注解指定了 provider 提供的 web 接口，而且 hello 办法的返回值 Call<HelloResponse>，和 provider 服务中 hello-obj 的返回值 HelloResponse 也是对应的，还有就是 hello 的入参对应着 provider 服务中 hello-obj 的入参，很相熟吧，的确，和 feign 太像了：

package com.bolingcavalry.consumer.service;

import com.bolingcavalry.client.HelloResponse;
import org.springframework.cloud.square.retrofit.core.RetrofitClient;
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;

@RetrofitClient("provider")
public interface HelloService {@GET("/hello-obj")
    Call<HelloResponse> hello(@Query("name") String name);
}

• 接下来是调用 provider 服务中 hello-obj 接口的代码 RemoteHello.java，如下所示，神奇的一幕呈现了，方才咱们只写了 HelloService 接口，并没有写它的实现，然而通过 Autowired 注解却能 从 spring 环境拿到实例间接应用，在 hello 办法中，并没有见到近程调用的代码，而是执行 helloService.hello，就能发动近程调用，拿到 provider 返回的后果：

package com.bolingcavalry.consumer.controller;

import com.bolingcavalry.client.HelloResponse;
import com.bolingcavalry.consumer.service.HelloService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.io.IOException;

@RestController
public class RemoteHello {@Autowired(required = false)
    HelloService helloService;

    @GetMapping("/remote-obj")
    public HelloResponse hello(@RequestParam("name") String name) throws IOException {return helloService.hello(name).execute().body();
    }
}

• 看到这里，聪慧的您肯定会感觉欣宸就是个 <font color=”blue”> 没见过世面的乡巴佬 </font>：定义 HelloService 接口，无需开发实现类，这玩意在 mybatis 不就有了嘛，竟然敢说 ” 神奇 ”，我感觉您说得对，欣宸的确没见识，少见多怪的 …
• 单元测试类如下，因为返回的是 json 对象，因而能够用 andExpect 办法再配合 MockMvcResultMatchers，对 json 进行查看：

package com.bolingcavalry.consumer.controller;

import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import static org.hamcrest.Matchers.is;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@SpringBootTest
@AutoConfigureMockMvc
@Slf4j
class RemoteHelloTest {

    private MockMvc mvc;

    @Autowired
    private WebApplicationContext webApplicationContext;

    @BeforeEach
    public void setUp() {
        // 在单元测试的时候，MockHttpServletResponse 实例的 characterEncoding 默认是 ISO-8859-1，// 失去的字符串打印进去也是乱码，// 上面的设置能够解决此问题
        if (null==mvc) {
            mvc = MockMvcBuilders
                    .webAppContextSetup(webApplicationContext)
                    .addFilter((request, response, chain) -> {response.setCharacterEncoding("UTF-8"); // this is crucial
                        chain.doFilter(request, response);
                    }, "/*")
                    .build();}
    }

    @Test
    void hello() throws Exception {
        // 申请参数是用户名，实时生成一个
        String name = System.currentTimeMillis() + "程序员 A";

        // 申请
        String responseString = mvc.perform(
                MockMvcRequestBuilders
                        .get("/remote-obj")
                        .param("name", name)
                        .accept(MediaType.APPLICATION_JSON)
        )
                .andExpect(status().isOk())                           // 验证状态
                .andExpect(jsonPath("$.name", is(name)))    // 验证 json 中返回的字段是否含有 name
                .andDo(print())
                .andReturn()
                .getResponse()
                .getContentAsString();

        log.info("response in junit test :\n" + responseString);
    }
}

• 执行单元测试，如下图，顺利通过：

consumer-retrofit-webflux，基于 spring-cloud-square 的 retrofit + webflux

• 最初退场的是 consumer-retrofit-webflux，pom.xml 如下，依赖库是 spring-cloud-square-retrofit + spring-boot-starter-webflux 的组合：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>spring-cloud-square-tutorials</artifactId>
        <groupId>com.bolingcavalry</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>consumer-retrofit-webflux</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.bolingcavalry</groupId>
            <artifactId>client</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-square-retrofit</artifactId>
            <version>0.4.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-square-retrofit-webclient</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <!--skip deploy (this is just a test module) -->
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

• 配置文件 application.yml:

spring:
  application:
    name: consumer-retrofit-webflux

server:
  port: 18083

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

• 启动类 RetrofitWebfluxApplication.java

  package com.bolingcavalry.consumer;
  
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  
  @SpringBootApplication
  public class RetrofitWebfluxApplication {public static void main(String[] args) {SpringApplication.run(RetrofitWebfluxApplication.class, args);
    }
  }

• 配置类 AppConfiguration.java，应用的注解是 EnableRetrofitClients，实例化的 Buider 对象是 WebClient.Builder，和后面的不一样，要分外留神：

package com.bolingcavalry.consumer;

import okhttp3.OkHttpClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.square.retrofit.webclient.EnableRetrofitClients;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.reactive.function.client.WebClient;

@Configuration
@EnableRetrofitClients
class AppConfiguration {
    @Bean
    @LoadBalanced
    public WebClient.Builder builder() {return WebClient.builder();
    }
}

• 接下来是接口定义，留神 hello 办法的返回值是 <font color=”blue”>Mono<HelloResponse></font>，这是 weflux 格调的返回值，代表异步的 0 个或一个元素：

package com.bolingcavalry.consumer.service;

import com.bolingcavalry.client.HelloResponse;
import org.springframework.cloud.square.retrofit.core.RetrofitClient;
import reactor.core.publisher.Mono;
import retrofit2.http.GET;
import retrofit2.http.Query;

@RetrofitClient("provider")
public interface HelloService {@GET("/hello-obj")
    Mono<HelloResponse> hello(@Query("name") String name);
}

• 最初是单元测试类，和后面的没啥区别：

package com.bolingcavalry.consumer.controller;

import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;
import static org.hamcrest.Matchers.is;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@SpringBootTest
@AutoConfigureMockMvc
@Slf4j
class RemoteHelloTest {

    private MockMvc mvc;

    @Autowired
    private WebApplicationContext webApplicationContext;

    @BeforeEach
    public void setUp() {
        // 在单元测试的时候，MockHttpServletResponse 实例的 characterEncoding 默认是 ISO-8859-1，// 失去的字符串打印进去也是乱码，// 上面的设置能够解决此问题
        if (null==mvc) {
            mvc = MockMvcBuilders
                    .webAppContextSetup(webApplicationContext)
                    .addFilter((request, response, chain) -> {response.setCharacterEncoding("UTF-8"); // this is crucial
                        chain.doFilter(request, response);
                    }, "/*")
                    .build();}
    }

    @Test
    void hello() throws Exception {
        // 申请参数是用户名，实时生成一个
        String name = System.currentTimeMillis() + "程序员 B";

        // 申请
        String responseString = mvc.perform(
                MockMvcRequestBuilders
                        .get("/remote-obj")
                        .param("name", name)
                        .accept(MediaType.APPLICATION_JSON)
        )
                .andExpect(status().isOk())                           // 验证状态
                .andExpect(jsonPath("$.name", is(name)))    // 验证 json 中返回的字段是否含有 name
                .andDo(print())
                .andReturn()
                .getResponse()
                .getContentAsString();

        log.info("response in junit test :\n" + responseString);
    }
}

• 运行单元测试，如下图，顺利通过，并且红框中所示的中文也没有乱码：

• 至此，spring-cloud-square 的三种类型，咱们全副编码体验了一遍，聪慧的您当然不会只满足于应用它们，接下来文章，咱们就去深刻 spring-cloud-square 源码，钻研其实现的细节，欣宸原创，必不会辜负您的期待！

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