Journal Entry Application

A Spring Boot REST API for managing journal entries with two versions:

• V1: Basic CRUD with in-memory storage (HashMap)
• V2: CRUD with MongoDB persistence

Prerequisites

• Java 17+
• Maven
• MongoDB running on serverURL

Running the Application

./mvnw spring-boot:run

The application runs on http://localhost:8080

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API Endpoints

V1 - In-Memory Storage (/journal)

Basic CRUD operations using an in-memory HashMap. Data is lost when the application restarts.

Method	Endpoint	Description
GET	/journal	Get all entries
POST	/journal	Create a new entry
GET	/journal/id/{id}	Get entry by ID
DELETE	/journal/id/{id}	Delete entry by ID
PATCH	/journal/id/{id}	Update entry by ID

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V2 - MongoDB Storage (/V2/journal)

CRUD operations with MongoDB persistence. Data is stored in the journal_entries collection.

Method	Endpoint	Description
GET	/V2/journal	Get all entries
POST	/V2/journal	Create a new entry
GET	/V2/journal/id/{id}	Get entry by ID
DELETE	/V2/journal/id/{id}	Delete entry by ID
PATCH	/V2/journal/id/{id}	Update entry by ID

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V2 API Usage Examples

Create Entry

curl -X POST http://localhost:8080/V2/journal \
  -H "Content-Type: application/json" \
  -d '{
    "title": "My First Entry",
    "content": "This is my journal content"
  }'

Response: true

Get All Entries

curl http://localhost:8080/V2/journal

Response:

[
  {
    "id": "67a4b1c2d3e4f5a6b7c8d9e0",
    "title": "My First Entry",
    "content": "This is my journal content",
    "date": null
  }
]

Get Entry by ID

curl http://localhost:8080/V2/journal/id/67a4b1c2d3e4f5a6b7c8d9e0

Response:

{
  "id": "67a4b1c2d3e4f5a6b7c8d9e0",
  "title": "My First Entry",
  "content": "This is my journal content",
  "date": null
}

Update Entry (PATCH)

curl -X PATCH http://localhost:8080/V2/journal/id/67a4b1c2d3e4f5a6b7c8d9e0 \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Updated Title",
    "content": "Updated content"
  }'

Response: Returns the updated entry

Delete Entry

curl -X DELETE http://localhost:8080/V2/journal/id/67a4b1c2d3e4f5a6b7c8d9e0

Response: true

---

Project Structure

src/main/java/com/example/firstusingmaven/
├── FirstUsingMavenApplication.java    # Main application class
├── controller/
│   ├── JournalEntryController.java    # V1 controller (in-memory)
│   └── JournalEntryControllerV2.java  # V2 controller (MongoDB)
├── entity/
│   ├── journalEntry.java              # V1 entity
│   └── journalEntryV2.java            # V2 entity (MongoDB document)
├── repository/
│   └── JournalEntryRepository.java    # MongoDB repository
└── service/
    └── JournalEntryServiceV2.java     # V2 service layer

MongoDB Configuration

Configuration in application.properties:

spring.data.mongodb.uri=mongodb://localhost:27017/journalDb

The V2 entries are stored in the journal_entries collection in the journalDb database.

Journal Entry V2 Schema

Field	Type	Description
id	String	MongoDB ObjectId (auto-generated)
title	String	Entry title
content	String	Entry content
date	Date	Entry date (optional)