Micro Services

How to create springboot app:

1.Using spring cli
2. https://start.spring.io/
3.Maven and dependencys




RestTemplate resttemplate = new RestTemplate();

resttemplate.getForObject(Stirng Url, Object out put Class);


Creating Bean in Spring boot


In Main method of spring

@SpringBootApplication
public  Main class{

@Bean
public RestTemplate getRestTemplate(){
    return new RestTemplate();
}

public void main method{
}


}

in Controller

@Autowired
RestTemplate reasttemplate;


resttemplate.getForObject()

Webclient vs Resttemplate

Webclint: Async requests
Resttemplate:  sync request


to handle web urls we have service discovery concept

client <----> service discovery <-----> service 1, service 2, service 3


download euraka server from start.spring.io.

and put dependency as Euraka Server

need to add below dependency for client and version


            <dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
and in properties add
            <spring-cloud.version>Greenwich.SR3</spring-cloud.version>


and add applicatoin name in application.properties.
spring.application.name=testapp

how to to discover the servec url

on @RestTemplate use  @LoadBalanced keyword and in the resttemplate url use application.name value to discover

Example

service application name->RBAC-SERVICE

resttemplate.getForObject("http://RBAC-SERVICE/getpermissions")