Create Micro service Project with many services and running one by one

You may have build the all the microservices in a single project or One project has many micro services.

In that case how to run those services picking up one by one as needed.

Example i have taken  from

https://spring.io/blog/2015/07/14/microservices-with-spring


eg : we have three micro services projects.
1. Registration server - eureka server
2. Account service
3. Web

How to run without building the jar:

we use maven and use spring-boot plugin to specify 'run' and give the main class with "-Dstart-class" tag

below is the three sample commands, run from the sample project directory where the POM file exist.(where you run mvn clean package  command)

mvn spring-boot:run -Dstart-class=io.pivotal.microservices.services.registration.RegistrationServer

mvn spring-boot:run -Dstart-class=io.pivotal.microservices.services.accounts.AccountsServer

mvn spring-boot:run -Dstart-class=io.pivotal.microservices.services.web.WebServer



How to run with Jar

Since we have few main classes

1. We need to specify the maven what is our main class

<properties>
<start-class>io.pivotal.microservices.services.Main</start-class>
</properties>

2. Create One single class with Main method. 
We call it Main.java
As we can. specify only one main class, we need to create a class with one main method which will guide to / call to other main methods (RegistrationServer.java , AccountsServer.java, WebServer.java)



3. Run jar with calling each service via Main.java
open three command lines and execute below three command, which will up three services

java -jar target/microservices-demo-2.0.0.RELEASE.jar registration
java -jar target/microservices-demo-2.0.0.RELEASE.jar accounts
java -jar target/microservices-demo-2.0.0.RELEASE.jar web


----------------------------------------------------------------below code snipet for Main.java--------------

If you do not create Main.java, still maven will build the project without error, but running this you will get 
Exception in thread "main" java.lang.ClassNotFoundException: io.pivotal.microservices.services.Main


----------------------------------------------------------------------------------

package io.pivotal.microservices.services;

import io.pivotal.microservices.services.accounts.AccountsServer;
import io.pivotal.microservices.services.registration.RegistrationServer;
import io.pivotal.microservices.services.web.WebServer;

/**
 * Allow the servers to be invoked from the command-line. The jar is built with
 * this as the Main-Class in the jar's MANIFEST.MF.
 * 
 * @author Paul Chapman
 */
public class Main {

 public static void main(String[] args) {

  String serverName = "NO-VALUE";

  switch (args.length) {
  case 2:
   // Optionally set the HTTP port to listen on, overrides
   // value in the -server.yml file
   System.setProperty("server.port", args[1]);
   // Fall through into ..

  case 1:
   serverName = args[0].toLowerCase();
   break;

  default:
   usage();
   return;
  }

  if (serverName.equals("registration") || serverName.equals("reg")) {
   RegistrationServer.main(args);
  } else if (serverName.equals("accounts")) {
   AccountsServer.main(args);
  } else if (serverName.equals("web")) {
   WebServer.main(args);
  } else {
   System.out.println("Unknown server type: " + serverName);
   usage();
  }
 }

 protected static void usage() {
  System.out.println("Usage: java -jar ...  [server-port]");
  System.out.println(
    "     where server-name is 'reg', 'registration', " + "'accounts' or 'web' and server-port > 1024");
 }
}