1. 创建SpringBoot工程

创建父工程及三个子模块，其中一个模块作为注册中心，另外两个作为服务提供者。

pom

<?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><groupId>org.example</groupId><artifactId>registerTest</artifactId><packaging>pom</packaging><version>1.0-SNAPSHOT</version><modules><module>server</module><module>provider1</module><module>provider2</module></modules><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.2.1.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpclient</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.1.23</version></dependency></dependencies></project>

2. 实现http访问

注意：这里目前用的是同步请求，实际用异步才是合适的

package http.client;import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;public class HttpClient {private String url;private String contentType;private String encoding;private JSONObject data;public HttpClient(String url, String encoding, String contentType, JSONObject data) {this.url = url;this.data = data;this.encoding = encoding == null ? "UTF-8" : encoding;this.contentType = contentType == null ? "application/json" : contentType;}public JSONObject httpGet() throws Exception {try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {HttpGet httpGet = new HttpGet(url);HttpResponse response = httpClient.execute(httpGet);if (response.getStatusLine().getStatusCode() != 200) {
//            throw new Exception("调用服务端异常.");return getResult(false, "调用服务端异常.");}HttpEntity res = response.getEntity();String resultData = EntityUtils.toString(res);System.out.println("从服务端返回结果: " + resultData);return JSONObject.parseObject(resultData);} catch (Exception e) {e.printStackTrace();}return getResult(false, "");}public JSONObject httpPost() throws Exception {try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {String json = JSONObject.toJSONString(data);StringEntity entity = new StringEntity(json);entity.setContentEncoding(encoding);entity.setContentType(contentType);HttpPost httpPost = new HttpPost(url);httpPost.setEntity(entity);HttpResponse response = httpClient.execute(httpPost);if (response.getStatusLine().getStatusCode() != 200) {return getResult(false, "调用服务端异常.");}HttpEntity res = response.getEntity();String resultData = EntityUtils.toString(res);System.out.println("从服务端返回结果: " + resultData);} catch (Exception e) {e.printStackTrace();}return getResult(false, "");}public static JSONObject getResult(boolean res, String msg) {return new JSONObject(){{put("res", res);put("msg", msg);}};}
}

实现一个简单的注册表结构，代表模块的名称和ip

package common;public class RegisterTable {private String name;private String ip;public RegisterTable(String name, String ip) {this.name = name;this.ip = ip;}public String getIp() {return ip;}
}

3. 注册中心实现

实现注册表管理，增加，删除，查询

package register.list;import com.alibaba.fastjson.JSONObject;
import common.RegisterTable;
import http.client.HttpClient;
import org.springframework.stereotype.Component;import java.util.ArrayList;
import java.util.HashMap;@Component
public class RegisterList {HashMap<String, ArrayList<RegisterTable>> hashMap = new HashMap<>();public JSONObject add(String name, String ip) {ArrayList<RegisterTable> list = hashMap.get(name);if (list == null) {list = new ArrayList<RegisterTable>();} else {for (RegisterTable table : list) {if (table.getIp().equals(ip)) {return HttpClient.getResult(false, "repeat");}}}RegisterTable registerTable = new RegisterTable(name,ip);list.add(registerTable);hashMap.put(name, list);return HttpClient.getResult(true, "success");}public HashMap<String, ArrayList<RegisterTable>> getAll() {return hashMap;}public ArrayList<RegisterTable> getByName(String name) {return hashMap.get(name);}
}

提供注册接口：

package register.control;import com.alibaba.fastjson.JSONObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import register.list.RegisterList;@RestController
@RequestMapping("/register")
public class Register {@AutowiredRegisterList registerList;@PostMapping("/register")public JSONObject register(@RequestBody JSONObject data) {//处理注册逻辑return registerList.add(data.getString("name"), data.getString("ip"));}@GetMapping("/list/{name}")public Object getList(@PathVariable(value = "name", required = true) String name) {//获取注册列表return registerList.getByName(name);}@GetMapping("/list/all")public Object getList() {return registerList.getAll();}
}

4. provider模块

功能：项目启动后发送注册信息到注册中心模块。

package common.register;import com.alibaba.fastjson.JSONObject;
import http.client.HttpClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;@Component
public class Register implements ApplicationRunner {@Value("${model.name}")String name;@Value("${model.host}")String host;@Value("${model.port}")String port;@Value("${register.url}")String url;//发送注册消息@Overridepublic void run(ApplicationArguments args) throws Exception {register();}private void register() throws Exception {JSONObject data = new JSONObject() {{put("name", name);put("ip", "http://" + host + ":" + port);}};HttpClient client = new HttpClient(url, null, null, data);client.httpPost();}
}

application.yml

server:port: 8001model:name: "provider"port: "8001"host: "127.0.0.1"register:url: "http://localhost:8080/register/register"

另外一个provider也是一样，不过端口不同

5. 测试

启动后：

查询注册表：两个模块都已经注册。