EUREKA Client 无法连接注册中心问题解决方案【连接被拒绝、不支持SSL协议消息、不能向任意已知的服务器发送请求】

版本：HOXTON.SR8

主要报错信息如下：

//无法连接注册中心
DiscoveryClient_CLIENT1/host.docker.internal:client1:8089 - registration failed Cannot execute request on any known server
 
com.netflix.discovery.DiscoveryClient    : DiscoveryClient_CLIENT1/host.docker.internal:client1:8089 - was unable to send heartbeat!
 
com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server
 
//使用了https协议
Caused by: javax.net.ssl.SSLException: Unsupported or unrecognized SSL message

我的方法也许不能帮你解决问题，但是一定能帮你排除掉一部分问题！

解决方法如下：

1. application.yml文件或者properties文件中的service-url替换为serviceUrl，default-zone替换为defaultZone，亲测有用，能解决一部分问题，重点检查拼写！！！

2. 服务端关闭验证：

security: 
    basic: 
        enabled: false

感觉没啥效果

3. client端 fetch-registry未开启，在配置文件中把 eureka.client.fetch-registry设置为true，亲测有用，不过注册中心就别开这个配置了

4. 使用了安全验证之后，服务端需要关闭CSRF验证，关闭方法在后面

5. 注册地址注意使用http协议而不要使用https协议，亲测有用，IDE有时候会自动帮你修改为https协议

6. 服务端server.port端口就是你的注册中心注册服务的端口，如果你的server.port端口就是8761，那么你的注册地址中端口也是8761！

7. 注册地址拼写错误，例如http://root:root@localhost:8761/eurake，看出了错误的地方了吗？注意 eurake 这个地方，正确的拼写是 eureka !一定要详细检查，我就是这个地方弄错了！

8. application.yml 文件要放在resources文件夹中，注意检查，很多朋友都是这个问题

9. server端的启动一定要在client端之前！！！

附上我的配置,实在不行可以用我的试试：

server端：application.yml

server:
  port: 8761
  address: localhost
spring:
  security:
    user:
      name: root
      password: root
security:
  basic:
    enabled: false
eureka:
  instance:
    hostname: localhost
  client:
    fetch-registry: false
    register-with-eureka: false
    serviceUrl:
      defaultZone: http://root:root@localhost:8761/eureka

server端pom.xml

<?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>servicecenter1</artifactId>
    <version>2.0.9-SNAPSHOT</version>
 
    <name>servicecenter1</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>
 
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring.cloud-version>Hoxton.SR8</spring.cloud-version>
    </properties>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
 
    <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>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
 
    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>3.1.0</version>
                </plugin>
                <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
                <plugin>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                </plugin>
                <plugin>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.5.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.8.2</version>
                </plugin>
                <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
                <plugin>
                    <artifactId>maven-site-plugin</artifactId>
                    <version>3.7.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-project-info-reports-plugin</artifactId>
                    <version>3.0.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

server端关闭csrf验证:

package org.example.securityfonfig;
 
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 
/**
 * @author hello 师姐
 */
@EnableWebSecurity
@Configuration
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable();
        super.configure(http);
    }
}

server端启动验证:

package org.example;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
 
/**
 * Hello world!
 *
 * @author 17715
 */
@SpringBootApplication
@EnableEurekaServer
public class App {
 
    public static void main(String[] args) {
        new SpringApplicationBuilder(App.class).web(WebApplicationType.SERVLET).run(args);
 
    }
}

client端application.yml

server:
  port: 8089
spring:
  application:
    name: client1
  security:
    user:
      name: root
      password: root
eureka:
  client:
    serviceUrl:
      defaultZone: http://root:root@localhost:8761/eureka
    fetch-registry: true
    register-with-eureka: true

client 端 pom.xml:

<?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>eurakeclient</artifactId>
    <version>1.0-SNAPSHOT</version>
 
    <name>eurakeclient</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>
 
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring.cloud-version>Hoxton.SR8</spring.cloud-version>
    </properties>
    <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>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <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.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
 
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
 
    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>3.1.0</version>
                </plugin>
                <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
                <plugin>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                </plugin>
                <plugin>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.5.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.8.2</version>
                </plugin>
                <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
                <plugin>
                    <artifactId>maven-site-plugin</artifactId>
                    <version>3.7.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-project-info-reports-plugin</artifactId>
                    <version>3.0.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

client端启动文件:

package org.example;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
 
/**
 * Hello world!
 *
 * @author 17715
 */
@SpringBootApplication
@EnableEurekaClient
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}