Java（六）：Eureka项目搭建、数据请求

左手的ㄟ右手 2024-03-17 12:17 28阅读 0赞

#### Eureka项目搭建、数据请求 ####

*   *  Eureka简介
     *  Eureka项目创建
     *   *  1、新建Maven项目
         *  2、只保留Maven项目的依赖文件
         *  3、创建子模块（Eureka服务模块）
         *  4、修改\`pom.xml\`
         *  5、创建并修改配置文件
         *  6、添加Eureka注解
         *  7、运行
         *  8、创建其他服务
         *  9、修改\`pom.xml\`
         *  10、创建并修改配置文件
         *  11、添加Eureka注解
         *  12、添加项目服务
         *  13、运行
         *  14、访问404解决
         *  15、项目目录结构
     *  搭建Eureka集群
     *   *  1、准备
         *  2. 创建 Eureka Server 模块
         *  3、运行
         *  4、创建 Eureka Client 模块并注册到Eureka服务中
         *  5、运行
         *  6、项目目录结构
     *  网络请求获取数据
     *   *  1、 创建项目
         *  2、 创建请求
         *  3、 运行
         *  4、 目录结构
     *  利用Eureka实现服务间数据请求
     *   *  1、 创建项目
         *  2、 添加依赖
         *  3、 \`demo/eureka-server\`
         *  4、 \`demo/service-01\`
         *  5、 \`demo/service-02\`
         *  6、 运行
         *  7、 目录结构

### Eureka简介 ###

> Eureka采用的是Server/Client的模式进行设计。
> 
> Server扮演了服务注册中心的角色，为Client提供服务注册和发现的功能，维护着注册到自身的Client的相关信息，同时提供接口给Client获取到注册表中其他服务的信息。
> 
> Client将有关自己的服务的信息通过一定的方式登记到Server上，并在正常范围内维护自己信息的一致性，方便其他服务发现自己，同时可以通过Server获取到自己的依赖的其他服务信息，从而完成服务调用。

> Eureka功能主要包括：`服务注册`、`服务续约`、`服务剔除`、`服务下线`、`获取注册表信息`、`远程调用`等。

*  以下是Eureka几个角色的解释：
    
     *  `Eureka服务端`：负责服务注册、发现并管理每项服务的中心。
     *  `Eureka实例`：服务（如订单系统）部署多个服务器，每个服务器上提供的服务都是实例。
     *  `Eureka服务`：指提供特定服务功能的服务，例如：订单系统，同一服务可以提供多个实例;
     *  `Eureka客户端`：主要向服务中心注册自己成为服务。但它既可以是服务提供者，也可以是消费者。它与Eureka实例感觉相似，但实际上意义不同。

### Eureka项目创建 ###

#### 1、新建Maven项目 ####

![在这里插入图片描述][c434ba2bf0d34e57b383c9acce6e396c.png_pic_center]

#### 2、只保留Maven项目的依赖文件 ####

> `pom.xml`文件作为后续创建的子模块依赖的父依赖文件

![在这里插入图片描述][46461164dd77493e8a30e29c7e97940b.png_pic_center]

#### 3、创建子模块（Eureka服务模块） ####

![在这里插入图片描述][0a10cf2ee9b34419b717045caab55673.png_pic_center]

![在这里插入图片描述][6ab9037f91b947108c495b6faa6019ff.png_pic_center]

![在这里插入图片描述][e862025c06a34fddb98a7794fb3b2fdb.png_pic_center]

#### 4、修改`pom.xml` ####

***`demo/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>com.example.demo</groupId>
        <artifactId>demo</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <packaging>pom</packaging>
    
        <modules>
            <module>demo-eureka</module>
        </modules>
    
        <properties>
            <java.version>1.8</java.version>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <spring-boot.version>2.6.13</spring-boot.version>
            <spring-cloud.version>2021.0.5</spring-cloud.version>
        </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>${spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>${spring-boot.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.1</version>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <version>${spring-boot.version}</version>
                    <executions>
                        <execution>
                            <id>repackage</id>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    
    </project>

***`demo/demo-eureka/pom.xml`***

#### 5、创建并修改配置文件 ####

***`demo/demo-eureka/src/main/resources/application.yml`***

server:
      port: 8000
    
    spring:
      application:
        name: demo-eureka
    
    eureka:
      instance:
        hostname: 127.0.0.1
      client:
        register-with-eureka: false   # 是否将自己注册到 Eureka-Server 中，默认的为 true
        fetch-registry: false         # 是否需要拉取服务信息，默认未true
        service-url:
          defaultZone: http://${
        eureka.instance.hostname}:${
        server.port}/eureka/  # 注册中心地址

#### 6、添加Eureka注解 ####

***`demo/demo-eureka/src/main/java/com/example/demo/demoeureka/DemoEurekaApplication.java`***

package com.example.demo.demoeureka;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    @EnableEurekaServer
    @SpringBootApplication
    public class DemoEurekaApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(DemoEurekaApplication.class, args);
        }
    
    }

#### 7、运行 ####

![在这里插入图片描述][1cf89a15c1144742a12043aa9524ff94.png_pic_center]

#### 8、创建其他服务 ####

![在这里插入图片描述][89efa4326fa746c3bd83e41698593053.png_pic_center]

#### 9、修改`pom.xml` ####

***`demo/pom.xml`***

<packaging>pom</packaging>
    
    <modules>
        <module>demo-eureka</module>
        <module>demo-one</module>
        <module>demo-two</module>
    </modules>

***`demo/demo-one/pom.xml`***

***`demo/demo-two/pom.xml`***

#### 10、创建并修改配置文件 ####

> 把服务注册到Eureka中

***`demo/demo-one/src/main/resources/application.yml`***

server:
      port: 8001
    
    spring:
      application:
        name: demo-one
    
    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:8000/eureka/

***`demo/demo-two/src/main/resources/application.yml`***

server:
      port: 8002
    
    spring:
      application:
        name: demo-two
    
    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:8000/eureka/

#### 11、添加Eureka注解 ####

***`demo/demo-one/src/main/java/com/example/demo/demoone/DemoOneApplication.java`***

package com.example.demo.demoone;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    @EnableEurekaClient
    @SpringBootApplication
    public class DemoOneApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(DemoOneApplication.class, args);
        }
    
    }

***`demo/demo-two/src/main/java/com/example/demo/demotwo/DemoTwoApplication.java`***

package com.example.demo.demotwo;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    @EnableEurekaClient
    @SpringBootApplication
    public class DemoTwoApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(DemoTwoApplication.class, args);
        }
    
    }

#### 12、添加项目服务 ####

![在这里插入图片描述][f619d978d172429891907321a1fa25a8.png_pic_center]

#### 13、运行 ####

![在这里插入图片描述][23e2d4a6fa154f869340ce685b57e22d.png_pic_center]

#### 14、访问404解决 ####

![在这里插入图片描述][63ce7a8dd68049f581414d19d0ad86e9.png_pic_center]

***开启监控服务配置`demo/demo-one/src/main/resources/application.yml`***  
***开启监控服务配置`demo/demo-two/src/main/resources/application.yml`***

management:
      endpoints:
        web:
          exposure:
            include: "*"

![在这里插入图片描述][bdb17d801e924812887cd87dedb13d33.png_pic_center]

#### 15、项目目录结构 ####

![在这里插入图片描述][07cf8c8fe8484c289f08ab5b4011d7d0.png_pic_center]

### 搭建Eureka集群 ###

> 应对服务挂了找不到服务的问题

#### 1、准备 ####

> `SwitchHosts`：用于修改 IP 和 域名 的映射
> 
> [https://github.com/oldj/SwitchHosts/releases][https_github.com_oldj_SwitchHosts_releases]

![在这里插入图片描述][f301e91faffa45229d7022b7cd52bc8a.png_pic_center]

#### 2. 创建 Eureka Server 模块 ####

![在这里插入图片描述][56a4f9ac0c104ceab1de34c7eab2ad5a.png_pic_center]

***`demo/pom.xml`***

<packaging>pom</packaging>
    
    <modules>
        <module>eureka-server-01</module>
        <module>eureka-server-02</module>
        <module>eureka-server-03</module>
        <module>eureka-client-01</module>
    </modules>

***`demo/eureka-server-01`、`demo/eureka-server-02`、`demo/eureka-server-03`***

*  启动类
    
     *  `demo/eureka-server-01/src/main/java/com/example/demo/eurekaserver01/EurekaServer01Application.java`
        
            package com.example.demo.eurekaserver01;
            
            import org.springframework.boot.SpringApplication;
            import org.springframework.boot.autoconfigure.SpringBootApplication;
            import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
            
            @EnableEurekaServer
            @SpringBootApplication
            public class EurekaServer01Application {
                    
                public static void main(String[] args) {
                    
                    SpringApplication.run(EurekaServer01Application.class, args);
                }
            }
     *  `demo/eu¬reka-server-02/src/main/java/com/example/demo/eurekaserver01/EurekaServer02Application.java`
        
            package com.example.demo.eurekaserver02;
            
            import org.springframework.boot.SpringApplication;
            import org.springframework.boot.autoconfigure.SpringBootApplication;
            import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
            
            @EnableEurekaServer
            @SpringBootApplication
            public class EurekaServer02Application {
                    
                public static void main(String[] args) {
                    
                    SpringApplication.run(EurekaServer02Application.class, args);
                }
            }
     *  `demo/eureka-server-03/src/main/java/com/example/demo/eurekaserver01/EurekaServer03Application.java`
        
            package com.example.demo.eurekaserver03;
              
            import org.springframework.boot.SpringApplication;
            import org.springframework.boot.autoconfigure.SpringBootApplication;
            import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
              
            @EnableEurekaServer
            @SpringBootApplication
            public class EurekaServer03Application {
                    
              public static void main(String[] args) {
                    
                  SpringApplication.run(EurekaServer03Application.class, args);
              }
            }
 *  配置项
    
     *  `demo/eureka-server-01/src/main/resources/application.yml`
        
            server:
            port: 8001
            
            spring:
            application:
            name: eureka-server-01
            
            eureka:
            instance:
            hostname: www.eureka-server-01.com
            client:
            register-with-eureka: false   # 是否将自己注册到 Eureka-Server 中，默认的为 true
            fetch-registry: false         # 是否需要拉取服务信息，默认未true
            service-url:
              defaultZone: http://www.eureka-server-02.com:8002/eureka/,http://www.eureka-server-03.com:8003/eureka/ # 注册中心地址
     *  `demo/eureka-server-02/src/main/resources/application.yml`
        
            server:
              port: 8002
            
            spring:
              application:
                name: eureka-server-02
            
            eureka:
              instance:
                hostname: www.eureka-server-02.com
              client:
                register-with-eureka: false   # 是否将自己注册到 Eureka-Server 中，默认的为 true
                fetch-registry: false         # 是否需要拉取服务信息，默认未true
                service-url:
                  defaultZone: http://www.eureka-server-01.com:8001/eureka/,http://www.eureka-server-03.com:8003/eureka/ # 注册中心地址
     *  `demo/eureka-server-03/src/main/resources/application.yml`
        
            server:
              port: 8003
            
            spring:
              application:
                name: eureka-server-03
            
            eureka:
              instance:
                hostname: www.eureka-server-03.com
              client:
                register-with-eureka: false   # 是否将自己注册到 Eureka-Server 中，默认的为 true
                fetch-registry: false         # 是否需要拉取服务信息，默认未true
                service-url:
                  defaultZone: http://www.eureka-server-01.com:8001/eureka/,http://www.eureka-server-02.com:8002/eureka/ # 注册中心地址

#### 3、运行 ####

![在这里插入图片描述][6e70d2a1feeb44e1a082a1dff1fe58b5.png_pic_center]

#### 4、创建 Eureka Client 模块并注册到Eureka服务中 ####

![在这里插入图片描述][7d83a0d6f1954193bfcf915f0ef52be4.png_pic_center]

*  启动类
    
     *  `demo/eureka-client-01/src/main/java/com/example/demo/eurekaclient01/EurekaClient01Application.java`
        
            package com.example.demo.eurekaclient01;
            
            import org.springframework.boot.SpringApplication;
            import org.springframework.boot.autoconfigure.SpringBootApplication;
            import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
            
            @EnableEurekaClient
            @SpringBootApplication
            public class EurekaClient01Application {
                    
                public static void main(String[] args) {
                    
                    SpringApplication.run(EurekaClient01Application.class, args);
                }
            }
 *  配置项
    
     *  `demo/eureka-client-01/src/main/resources/application.yml`
        
            server:
              port: 8081
            
            spring:
              application:
                name: eureka-client-01
            
            eureka:
              instance:
                hostname: www.eureka-client-01.com
                instance-id: eureka-client-01
              client:
                service-url:
                  defaultZone: http://www.eureka-server-01.com:8001/eureka/,http://www.eureka-server-02.com:8002/eureka/,http://www.eureka-server-03.com:8003/eureka/
            
            management:
              endpoints:
                web:
                  exposure:
                    include: "*"

#### 5、运行 ####

![在这里插入图片描述][555c7d5dd4be4e5cbce534ed0cae5309.png_pic_center]

#### 6、项目目录结构 ####

![在这里插入图片描述][6793faaf85354692aea1ddc44ed03c39.png_pic_center]

### 网络请求获取数据 ###

#### 1、 创建项目 ####

![在这里插入图片描述][18621565a74543ce9269f53aa95f3f90.png_pic_center]

![在这里插入图片描述][c1b9003f3231402286669c310f783773.png_pic_center]

![在这里插入图片描述][d361ab74e66443adbb331ed4277f5f75.png_pic_center]

***`demo/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>com.example.demo</groupId>
        <artifactId>demo</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <packaging>pom</packaging>
    
        <modules>
            <module>service-01</module>
            <module>service-02</module>
        </modules>
    
        <properties>
            <java.version>1.8</java.version>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <spring-boot.version>2.6.13</spring-boot.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>${spring-boot.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.1</version>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <version>${spring-boot.version}</version>
                    <executions>
                        <execution>
                            <id>repackage</id>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    
    </project>

***`demo/service-01/pom.xml`***

***`demo/service-02/pom.xml`***

***`demo/service-01/src/main/resources/application.yml`***

server:
      port: 8001

***`demo/service-02/src/main/resources/application.yml`***

server:
      port: 8002

#### 2、 创建请求 ####

***`demo/service-01/src/main/java/com/example/demo/service01/TestController.java`***

package com.example.demo.service01;
    
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    @RestController
    @RequestMapping
    public class TestController {
        
    
        private final RestTemplate restTemplate = new RestTemplate();
    
        @GetMapping("msg")
        public String msg() {
        
            return "service-01 服务中请求 service-02";
        }
    
        @GetMapping("say")
        public String say() {
        
            String html = restTemplate.getForObject("https://www.example.com/", String.class);
            String msg = restTemplate.getForObject("http://127.0.0.1:8002/msg", String.class);
            return String.format("%s<h1 style=\"text-align: center;\">%s</h1>", html, msg);
        }
    
    }

***`demo/service-01/src/main/java/com/example/demo/service01/TestController.java`***

package com.example.demo.service02;
    
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    @RestController
    @RequestMapping
    public class TestController {
        
    
        private final RestTemplate restTemplate = new RestTemplate();
    
        @GetMapping("msg")
        public String msg() {
        
            return "service-02 服务中请求 service-01";
        }
    
        @GetMapping("say")
        public String say() {
        
            String html = restTemplate.getForObject("https://www.example.com/", String.class);
            String msg = restTemplate.getForObject("http://127.0.0.1:8001/msg", String.class);
            return String.format("%s<h1 style=\"text-align: center;\">%s</h1>", html, msg);
        }
    
    }

#### 3、 运行 ####

![在这里插入图片描述][6bd819a39e5a4a4faad4f78786d1432c.png_pic_center]

#### 4、 目录结构 ####

![在这里插入图片描述][f66049c271bc466080a7d0eaf142754f.png_pic_center]

### 利用Eureka实现服务间数据请求 ###

![在这里插入图片描述][f6517ec93f08425084f3ea35972e7445.png_pic_center]

#### 1、 创建项目 ####

![在这里插入图片描述][2eb76c36f9a140d6a9afc89d3cbe5f46.png_pic_center]

![在这里插入图片描述][b93a704db8224616a1fa916041a6794c.png_pic_center]

![在这里插入图片描述][333b570eac2d4e498e4704d7afdb3bc5.png_pic_center]

***`demo/pom.xml`***

<packaging>pom</packaging>
    
    <modules>
        <module>eureka-server</module>
        <module>service-01</module>
        <module>service-02</module>
    </modules>

#### 2、 添加依赖 ####

***`demo/pom.xml`***

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

#### 3、 `demo/eureka-server` ####

***`demo/eureka-server/src/main/resources/application.yml`***

server:
      port: 8001
    
    spring:
      application:
        name: eureka-server
    
    eureka:
      instance:
        hostname: www.eureka-server.com
      client:
        register-with-eureka: false   # 是否将自己注册到 Eureka-Server 中，默认的为 true
        fetch-registry: false         # 是否需要拉取服务信息，默认未true
        service-url:
          defaultZone: http://${
        eureka.instance.hostname}:${
        server.port}/eureka/ # 注册中心地址

***`demo/eureka-server/src/main/java/com/example/demo/eurekaserver/EurekaServerApplication.java`***

package com.example.demo.eurekaserver;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    @EnableEurekaServer
    @SpringBootApplication
    public class EurekaServerApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(EurekaServerApplication.class, args);
        }
    
    }

#### 4、 `demo/service-01` ####

***`demo/service-01/src/main/resources/application.yml`***

server:
      port: 8081
    
    spring:
      application:
        name: service-01
    
    eureka:
      instance:
        hostname: www.eureka-server.com
        instance-id: service-01
      client:
        service-url:
          defaultZone: http://www.eureka-server.com:8001/eureka/
    
    management:
      endpoints:
        web:
          exposure:
            include: "*"

***`demo/service-01/src/main/java/com/example/demo/service01/Service01Application.java`***

package com.example.demo.service01;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    @EnableFeignClients
    public class Service01Application {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(Service01Application.class, args);
        }
    
    }

***`demo/service-01/src/main/java/com/example/demo/service01/api/IService02.java`***

package com.example.demo.service01.api;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    
    @FeignClient(value = "SERVICE-02")
    public interface IService02 {
        
        @GetMapping("/getMsg")
        public String getMsg();
    }

***`demo/service-01/src/main/java/com/example/demo/service01/Service01Controller.java`***

package com.example.demo.service01;
    
    import com.example.demo.service01.api.IService02;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    
    @RestController
    @RequestMapping
    public class Service01Controller {
        
    
        @Resource
        private IService02 service02;
    
        @GetMapping("/say")
        public String say(){
        
            return service02.getMsg();
        }
    
        @GetMapping("getMsg")
        public String getMsg() {
        
            return "SERVICE-02 调用 SERVICE-01";
        }
    
    }

#### 5、 `demo/service-02` ####

***`demo/service-02/src/main/resources/application.yml`***

server:
      port: 8082
    
    spring:
      application:
        name: service-02
    
    eureka:
      instance:
        hostname: www.eureka-server.com
        instance-id: service-02
      client:
        service-url:
          defaultZone: http://www.eureka-server.com:8001/eureka/
    
    management:
      endpoints:
        web:
          exposure:
            include: "*"

***`demo/service-02/src/main/java/com/example/demo/service02/Service02Application.java`***

package com.example.demo.service02;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    @EnableFeignClients
    public class Service02Application {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(Service02Application.class, args);
        }
    
    }

***`demo/service-02/src/main/java/com/example/demo/service02/api/IService01.java`***

package com.example.demo.service02.api;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    
    @FeignClient(value = "SERVICE-01")
    public interface IService01 {
        
        @GetMapping("/getMsg")
        public String getMsg();
    }

***`demo/service-02/src/main/java/com/example/demo/service02/Service02Controller.java`***

package com.example.demo.service02;
    
    import com.example.demo.service02.api.IService01;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    
    @RestController
    @RequestMapping
    public class Service02Controller {
        
    
        @Resource
        private IService01 service01;
    
        @GetMapping("/say")
        public String say(){
        
            return service01.getMsg();
        }
    
        @GetMapping("getMsg")
        public String getMsg() {
        
            return "SERVICE-01 调用 SERVICE-02";
        }
    
    }

#### 6、 运行 ####

> 优先运行 `EurekaServerApplication` 启动类

![在这里插入图片描述][a89c5c256ccd41d09ae1d6614581585a.png_pic_center]

#### 7、 目录结构 ####

![在这里插入图片描述][d38de76a67f64a66814064a1982cf94c.png_pic_center]

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[f619d978d172429891907321a1fa25a8.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/15/62ccee23e7e64e0191a35c63930f1c23.png
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[https_github.com_oldj_SwitchHosts_releases]: https://github.com/oldj/SwitchHosts/releases
[f301e91faffa45229d7022b7cd52bc8a.png_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/15/2001be4e03c94c0c85da20225a0c9bae.png
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