.net framework 4.5 +steeltoe+ springcloud（二） 实现服务发现与调用功能

首先，写一个简单的可被调用的服务注册到服务中心，我们这命名为java-service,用的是IDEA创建一个spring boot项目，选择spring client类型。

修改application.properties，配置服务中心地址和服务端口号：

spring.application.name=java-service
​
server.port=3222
​
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

修改pom.xml，加入架包引用：

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

　　

 

 

修改主程序入口DemoclientApplication.java:

package com.ty.democlient;
​
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
​
@SpringBootApplication
@EnableEurekaClient
@RestController
public class DemoclientApplication {
​
    public static void main(String[] args) {
        SpringApplication.run(DemoclientApplication.class, args);
    }
​
    @Value("${server.port}")
    String port;
    @RequestMapping("/hi")
    public String home(@RequestParam String name) {
        return "hi "+name+",i am from port:" +port;
    }
}

　　

 

 

把服务跑起来之后，我们看到在服务中心已经能看见这个服务了：

打开浏览器输入http://localhost:3222/hi?name=demo，可以看到服务正常返回：

 

 

现在我们的目标是在另外一个.NET MVC项目里通过服务名就能正常调用到这个服务，来看看怎么做：

新建一个基于.Net Framework 4.5 的MVC项目，首先根目录还是要有一个appsettings.json的文件作为服务配置文件：

 

 

{
  "spring": {
    "application": {
      "name": "demo_netfetch"
    }
  },
  "eureka": {
    "client": {
      "serviceUrl": "http://localhost:8761/eureka/",
      "shouldFetchRegistry": true,
      "shouldRegisterWithEureka": true,
      "validate_certificates": false
    },
    "instance": {
      "port":
      // Remove comments to enable SSL requests
      // More changes in Program.cs are required if using direct C2C communications
      //,"securePortEnabled": true
    }
  },
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Debug",
      "Pivotal": "Debug",
      "Steeltoe": "Debug"
    }
  }
}

​

 

 

shouldFetchRegistry设置为true代表这是一个服务发现客户端

然后在项目目录下创建Service调用的类，配置具体调用的服务名，内容输出方式等：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using System.Web;
using Microsoft.Extensions.Logging;
using Steeltoe.Common.Discovery;
​
namespace DemoNetFetchClient.Services
{
    public class FetchServise : IFetchServise
    {
        DiscoveryHttpClientHandler _handler;
​
        private const string RANDOM_FORTUNE_URL = "http://java-service/hi?name=tian";//服务中心已注册的服务地址
        private ILogger<FetchServise> _logger;
​
        public FetchServise(IDiscoveryClient client, ILoggerFactory logFactory = null)
        {
            _handler = new DiscoveryHttpClientHandler(client);
            _logger = logFactory?.CreateLogger<FetchServise>();
        }
​
        public async Task<string> RandomFortuneAsync()
        {
            _logger?.LogInformation("RandomFortuneAsync");
            var client = GetClient();
            return await client.GetStringAsync(RANDOM_FORTUNE_URL);
​
        }
​
        private HttpClient GetClient()
        {
            var client = new HttpClient(_handler, false);
            return client;
        }
    }
}

 

 

注意这里需要引用扩展包：Steeltoe.Common.Discovery，从NuGet里加载就可以，注意版本，要选择NET专用的，而不是Core用的。

修改HomeController.cs,异步请求调用内部服务：

public class HomeController : Controller
    {
        IFetchServise _fortunes;
        ILogger<HomeController> _logger;
​
        public HomeController(IFetchServise fortunes,  ILoggerFactory logFactory = null)
        {
            _fortunes = fortunes;
            _logger = logFactory?.CreateLogger<HomeController>();
        }
​
        public async System.Threading.Tasks.Task<ActionResult> Index()
        {
            ViewBag.Message = await _fortunes.RandomFortuneAsync();
​
            return View();
        }
​

    }

 

 

修改Global.asax，注册服务客户端:

 这里要注意，如果项目是webapi程序，需要按Autofac集成webAPI的配置，具体请参考我的另一篇笔记：C# Autofac集成之Framework WebAPI

protected void Application_Start()
        {
​
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
​
            ApplicationConfig.RegisterConfig("development");
​
            var builder = new ContainerBuilder();
​
            // Add Microsoft Options to container
            builder.RegisterOptions();
​
            // Add Microsoft Logging to container
            builder.RegisterLogging(ApplicationConfig.Configuration);
​
            // Add Console logger to container
            builder.RegisterConsoleLogging();
​
            // Register all the controllers with Autofac
            builder.RegisterControllers(typeof(MvcApplication).Assembly);
​
            // Register IDiscoveryClient, etc.
            builder.RegisterDiscoveryClient(ApplicationConfig.Configuration);
​
            // Register FortuneService
            builder.RegisterType<FetchServise>().As<IFetchServise>().SingleInstance();
​
            // Create the Autofac container
            var container = builder.Build();
            DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
​
            // Get a logger from container
            var logger = container.Resolve<ILogger<MvcApplication>>();
​
            logger.LogInformation("Finished container build, starting background services");
​
            // Start the Discovery client background thread

            container.StartDiscoveryClient();
​
            logger.LogInformation("Finished starting background services");
        }

 

 

ok!done!程序跑起来效果，成功调用到服务中心内部服务java-service：