Expense-Tracker

Spring boot & Mongodb

Testcontainers dependency:

• gives the light weight throwaway instances of services like databases, message queues
• main advantage is we can run the service in a docker container and use the service to test our application

Mongodb:

• @Decument() - to get the spring save the class inside database - @Field() - to name a column @Indexed() - to retrieve data faster

• If we add an object into the database for the first time use insert() or else use save()

• we indexed the expenseName field in Expense class

• we can provide the custom query to spring data in mongodb repository

@Query("{'name': ?0}")
Optional<Expense.> findByName(String name);

@Query("{'name': ?0}, 'amount': ?1}")
Optional<Expense.> findByName(String name, String amount);

Sample Requests and Responds

Sample POST Request:

localhost:8080/api/expense

Payload

{
"expenseName": "Netflix",
"expenseCategory": "ENTERTAINMENT",
"expenseAmount": 500
}

Response:

201 Created

Sample GET request:

localhost:8080/api/expense

Response:

[
{
"id": "63a97e0665374f6d5cd7fc79",
"expenseName": "Netflix",
"expenseCategory": "ENTERTAINMENT",
"expenseAmount": 500
}
]

Sample PUT request:

localhost:8080/api/expense

Payload:

{
"id": "63a97e0665374f6d5cd7fc79",
"expenseName": "Netflix",
"expenseCategory": "ENTERTAINMENT",
"expenseAmount": 600
}

Response:

200 OK

Test Expense by name

Sample GET Request:

localhost:8080/api/expense/Netflix

Response:

{
"id": "63a97e0665374f6d5cd7fc79",
"expenseName": "Netflix",
"expenseCategory": "ENTERTAINMENT",
"expenseAmount": 600
}

Sample DELETE request:

localhost:8080/api/expense/63a97e0665374f6d5cd7fc79

Response:

204 No Content

Mongock - Handle database migrations

• To automate the application
  • one reason is applications are usually deployed in multiple environments
  • other reason is it is hard to manage database changes(add new fields, update existing fields, update records inside collection)
• like Mongock we have Flyway and Liquibase for relational databases

Mongock Quick start

• add mongock's bom to your pom file (which manages versions of all mongo projects) to dependency management

<dependency>
    <groupId>com.github.cloudyrock.mongock</groupId>
    <artifactId>mongock-bom</artifactId>
    <version>4.3.7</version>
    <type>pom</type>
</dependency>

• also add the driver

<dependency>
    <groupId>com.github.cloudyrock.mongock</groupId>
    <artifactId>mongock-spring-v5</artifactId>
    <version>4.3.8</version>
</dependency>  
  

• for runner

<dependency>
    <groupId>com.github.cloudyrock.mongock</groupId>
    <artifactId>mongodb-springdata-v3-driver</artifactId>
    <version>4.1.13</version>
</dependency>

• next enable mongock, open springboot application class and add the annotation @EnableMongock
• tell mongock where to find the database related codes config / DatabaseChangeLog

follow this tutorial