Mandate Management System

The Mandate Management System is a Java-based application built with Spring Boot and GraphQL. It manages mandates with functionality to create, update, delete, and retrieve mandates. The system includes robust error handling, retry mechanisms, and optimistic locking for concurrency control.

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Features

• GraphQL API:

  • Create a mandate
  • Update an existing mandate
  • Delete a mandate
  • Retrieve all mandates
  • Fetch a mandate by ID

• Transaction Management:

  • Ensures data consistency with @Transactional.

• Retry Mechanisms:

  • Automatic retries for transient failures using Spring Retry.

• Optimistic Locking:

  • Concurrency control via the @Version field.

• H2 In-Memory Database:

  • Quick setup and testing with in-memory storage.

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Project Structure

src/main/java/com/mandatesystem/ ├── domain # Entity classes (e.g., Mandate.java) ├── repository # JPA repository interfaces ├── service # Business logic and transaction management (e.g., MandateService.java) ├── graphql # GraphQL controllers and input classes └── exception # Custom exception handlers (optional)

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Prerequisites

1. Java: JDK 17 or higher.
2. Maven: For dependency management and project builds.
3. IDE: IntelliJ IDEA, Spring Tool Suite, or VS Code.

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Installation

1. Clone the repository:

   git clone <repository_url>
   cd mandate-management-system

2. Build the project:

   mvn clean install

3. Run the application: mvn spring-boot:run

API Endpoints GraphQL Path: Access the GraphQL API at: http://localhost:8080/graphql Use GraphiQL for interactive testing: http://localhost:8080/graphiql

GraphQL Schema Mandate Type

type Mandate { mandateId: ID mandateType: String effectiveDate: String expiryDate: String instructions: String version: Int lastModifiedBy: String lastModifiedDate: String } Queries Fetch All Mandates:

query { getMandates { mandateId mandateType effectiveDate expiryDate instructions } } Fetch Mandate by ID:

query { getMandateById(mandateId: "123e4567-e89b-12d3-a456-426614174000") { mandateId mandateType effectiveDate expiryDate instructions } } Mutations Create Mandate:

mutation { createMandate( mandateType: "Type1", effectiveDate: "2024-12-22", expiryDate: "2025-01-01", instructions: "Approve the budget" ) { mandateId mandateType effectiveDate expiryDate instructions } } Update Mandate:

mutation { updateMandate( mandateId: "123e4567-e89b-12d3-a456-426614174000", mandateType: "Updated Type", effectiveDate: "2024-12-23", expiryDate: "2025-02-01", instructions: "Updated instructions" ) { mandateId mandateType effectiveDate expiryDate instructions } } Delete Mandate:

mutation { deleteMandate(mandateId: "123e4567-e89b-12d3-a456-426614174000") } Configuration application.properties

spring.application.name=mandate-management-system

spring.datasource.url=jdbc:h2:mem:testdb spring.datasource.driver-class-name=org.h2.Driver spring.datasource.username=sa spring.datasource.password=password spring.datasource.initialization-mode=always

spring.jpa.hibernate.ddl-auto=update spring.jpa.show-sql=true

spring.graphql.path=/graphql spring.graphql.graphiql.enabled=true spring.graphql.graphiql.path=/graphiql

spring.h2.console.enabled=true spring.h2.console.path=/h2-console logging.level.org.hibernate.SQL=DEBUG logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE Testing Access the H2 Console:

URL: http://localhost:8080/h2-console JDBC URL: jdbc:h2:mem:testdb Username: sa, Password: password Use GraphiQL or Postman to test the GraphQL queries and mutations.

Future Improvements Implement additional error handling and input validation. Add pagination and filtering for getMandates. Integrate with a persistent database like MySQL or PostgreSQL. Contributing Feel free to fork the repository and submit pull requests. For major changes, please open an issue first to discuss what you would like to change.

License This project is licensed under the MIT License. See the LICENSE file for details.

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Steps to Add This File

1. Create a README.md file at the root of your repository.
2. Paste the content above into the file.
3. Commit the changes:

   git add README.md
   git commit -m "Add README with project details"
   git push

This README should provide clear, concise instructions and act as a guide for developers working on or reviewing the project. Let me know if any further adjustments are needed!