customer-self-service-backend

Lakeside Mutual: Customer Self-Service Backend

The Customer Self-Service backend provides an HTTP resource API for the Customer Self-Service frontend. Additionally, it connects to an ActiveMQ broker provided by the Policy Management backend in order to process insurance quote requests.

IDE

To view and edit the source code, we recommend the official Eclipse-based IDE Spring Tool Suite (STS). Other IDEs might work as well, but this application has only been tested with STS.

Installation

The Customer Self-Service backend is a Spring Boot application and its dependencies are managed with Apache Maven. To get started, install Java and Maven:

1. Make sure you have Java 8 or higher installed.
2. Install Maven (see https://maven.apache.org for installation instructions). Note that most IDEs, such as the Spring Tool Suite, already contain a bundled copy of Maven. If this project is only built and launched from within the IDE, this step can be skipped.

Launch Application

In order to launch the Customer Self-Service backend, you can run the command mvn spring-boot:run. When startup is completed, the output should look like this:

2018-05-07 14:21:13.011  INFO 12773 --- [  restartedMain] c.l.customerselfservice.DataLoader              : DataLoader has successfully imported all application dummy data, the application is now ready.

Alternatively, you can download and install the Spring Tool Suite:

1. Install Spring Tool Suite (you can download the IDE from https://spring.io/tools/sts)
2. Start Spring Tool Suite and create a new workspace or open an existing one
3. Import the project:
   
   1. Go to File -> Import -> Maven -> Existing Maven Projects
   2. Select the LakesideMutual repository as the root directory
   3. Enable the check mark for the customer-self-service-backend project
   4. Click Finish to import the project
4. Right-click on the project and select Run As -> Spring Boot App to start the application

By default, the Spring Boot application starts on port 8080. If this port is already used by a different application, you can change it in the src/main/resources/application.properties file.

Warnings about a java.net.ConnectException: Connection refused can safely be ignored. See the FAQ for details.

Logical Layers

The packages follow the conventions/recommendations of the original DDD book regarding technical layering:

• The presentation logic/layer can be found under interfaces.
• There are application and domain packages that contain business logic (the actual domain model and its usage).
• Data access and technical utilities can be found in infrastructure.

Springdoc Open API documentation

Springdoc is an automated JSON API documentation tool for APIs built with Spring. To access the documentation for the Customer Self-Service backend, go to the Swagger Web UI available at http://localhost:8080/swagger-ui/index.html. The native Swagger file is available at http://localhost:8080/v3/api-docs.

Testing

To run the automated tests for the Customer Self-Service backend, right-click on the project in the Spring Tool Suite and then click on Run As -> JUnit Test. The test classes are located in the src/test/java folder.

Enabling Persistence

By default, the database will be re-created when the application is started and any changes that were made are lost. This is configured in src/main/resources/application.properties by the following setting:

spring.jpa.hibernate.ddl-auto=create-drop

If you want to persist your changes across restarts, change the setting to:

spring.jpa.hibernate.ddl-auto=update

Circuit Breaker and JMX MBean (Demo/Proof-of-Concept)

The Customer Self-Service backend retrieves customer master data from the Customer Core service. The outgoing HTTP connection is protected by a simple Hystrix circuit breaker; dummy data is returned during connection problems.

The behavior of the connection and the @HystrixCommand can be observed via a simple JMX MBean; to simplify matters, the remote service class serves as the implementation of the MBean interface. To access the MBean, any JMX client can be used, for instance the command-line tool JConsole or the Spring Boot Admin appliation (see below).

Spring Boot Admin

The application is configured to connect to the Spring Boot Admin on startup. See the README to learn more.

Custom MBeans are accessible via the "Wallboard":

• Click on the hexagon for Customer Self-Service.
• Next, select JVM -> JMX on the left side of the screen. The known MBeans are then displayed on the right. Look for the entry com.lakesidemutual.customerselfservice.infrastructure and click on it to display the customerCoreService MBean.