Spring boot auf Tomcat mit externen Konfiguration

    I have finally simplified solution for reading custom properties from external location i.e outside of the spring boot project. Please refer to below steps.
Note: This Solution created and executed windows.Few commands and folders naming convention may vary if you are deploying application on other operating system like Linux..etc.

         1. Create a folder in suitable drive.
         eg: D:/boot-ext-config

         2. Create a .properties file in above created folder  with relevant property key/values and name it as you wish.I created dev.properties for testing purpose.
         eg :D:/boot-ext-config/dev.properties

            sample values:
            dev.hostname=www.example.com


        3. Create a java class in your application as below
        ------------------------------------------------------
        import org.springframework.boot.context.properties.ConfigurationProperties;
        import org.springframework.context.annotation.PropertySource;

        @PropertySource("classpath:dev.properties")
        @ConfigurationProperties("dev")
        public class ConfigProperties {
            private String hostname;

            //setters and getters
        }
        --------------------------------------------
         4. Add @EnableConfigurationProperties(ConfigProperties.class) to SpringBootApplication as below
        --------------------------------------------
        @SpringBootApplication
        @EnableConfigurationProperties(ConfigProperties.class)
        public class RestClientApplication {
            public static void main(String[] args)  {
                 SpringApplication.run(RestClientApplication.class, args);
        }
        }
        ---------------------------------------------------------
        5. In Controller classes we can inject the instance using @Autowired and fetch properties

        @Autowired
            private ConfigProperties configProperties;

        and access properties using getter method 
       System.out.println("**********hostName******+configProperties.getHostName());

Build your  spring boot maven project and run the below command to start application.

-> set SPRING_CONFIG_LOCATION=<path to your properties file>

->java -jar app-name.jar