Cloud Zookeeper
We will create 2 applications:
service producer:
https://github.com/spring-boot-tutorials/cloud-zookeeper-service-producer
running on localhost:8080
service consumer:
https://github.com/spring-boot-tutorials/cloud-zookeeper-service-consumer
running on localhost:8081
Install & Run Zookeeper Server
docker run --name zookeeper-server -p 2181:2181 zookeeper:latest
Service Producer Application
Create Initial Code Base
Go to https://start.spring.io/
Add the following dependencies:
spring-boot-starter-web
spring-cloud-starter-zookeeper-discovery
Click
Generate
Dependencies
Dependencies used in pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
</dependency>
Properties
Add the following properties into src/main/resources/application.yaml:
spring:
application:
name: my-service-provider
cloud:
zookeeper:
# uncomment if zookeeper server is running elsewhere
# connect-string: localhost:2181
discovery:
enabled: true
logging:
level:
org.apache.zookeeper.ClientCnxn: WARN
Controller
Create a new file src/main/java/com/example/spring_cloud_zookeeper/DefaultController.java:
@RestController
public class DefaultController {
@GetMapping("/helloworld")
public String helloWorld() {
return "Hello World!";
}
}
Main
Modify MainApplication.java:
@EnableDiscoveryClient
@SpringBootApplication
public class SpringCloudZookeeperApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudZookeeperApplication.class, args);
}
}
Run Application
mvn spring-boot:run
Service Consumer Application
Create Initial Code Base
Go to https://start.spring.io/
Add the following dependencies:
spring-boot-starter-web
spring-cloud-starter-zookeeper-discovery
spring-boot-starter-actuator
spring-cloud-starter-openfeign
Click
Generate
Dependencies
Dependencies used in pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
Properties
Add the following properties into src/main/resources/application.yaml:
server:
port: 8081
# uncomment if zookeeper server is running elsewhere
#spring:
# cloud:
# zookeeper:
# connect-string: localhost:2181
logging:
level:
org.apache.zookeeper.ClientCnxn: WARN
Configuration
Create a new file src/main/java/com/example/spring_cloud_zookeeper/DefaultFeignClient.java:
@Configuration
@EnableFeignClients
@EnableDiscoveryClient
public class DefaultFeignClient {
@Autowired
private TheClient theClient;
@FeignClient(name = "my-service-provider")
public interface TheClient {
@RequestMapping(path = "/helloworld", method = RequestMethod.GET)
@ResponseBody
String helloWorld();
}
public String helloWorld() {
return theClient.helloWorld();
}
}
Controller
Create a new file src/main/java/com/example/spring_cloud_zookeeper/DefaultController.java:
@RestController
public class DefaultController {
@Autowired
private DefaultFeignClient defaultFeignClient;
@GetMapping("/get-greeting")
public String greeting() {
return defaultFeignClient.helloWorld();
}
}
Run Application
mvn spring-boot:run