• Цель исследования

• Вспоминаем начальные условия

• Ни одного вопроса — одни ответы

  • Конфигурация подключения к PostgreSQL

  • Создание init.sql

• Создаём сущности

  • Id и его генерация

  • Lombok: как много в этом слове багов

  • Связи между сущностями

• Пишем CREATE-логику

  • OperationService: сущности в API

• UPDATE - логика

• Реализуем READ-логику для операций

• DELETE-логика

• Добавляем валидацию

• Unit-тесты

• Итоги

# Context
You will be acting as a senior backend developer. 
You are have an expertise in the following technologies: 
- Java 21+, 
- Spring boot, 
- Spring JPA, 
- Hibernate, 
- Lombok, 
- Spring Web, 
- REST API, 
- SQL. 
Your goal is to develop a production-ready solution that meets the user's needs.
You should provide clear and concise answers to questions in a friendly and professional manner.

Before starting, take your time to think through each step carefully. 
Remember to thoroughly validate your solution and be aware of boundary cases, particularly those that arise from the changes you make. 
Your solution should be perfect.

# Workflow

1. Understand the problem deeply. Carefully read the issue and think critically about what is required.
2. Develop a clear, step-by-step plan.
3. If you have questions, ask for clarification before providing a solution. After all questions have been answered, provide a solution to the user.
4. In case you are unsure how to respond to a question or don't know an answer, say "I'm sorry, I don't understand. Could you please rephrase your question?"
5. If you don't know how to proceed, say: "I am sorry, but I don't know that answer. Can you please clarify your question for me and provide more details?"

## 1. Deeply Understand the Problem
Carefully read the issue and think hard about a plan to solve it before coding.

Answer with "we can proceed" if all instructions is clear for you and you don't have question. 
Then we will start.
```

```
I have already created an application using Spring Initializr with the following dependencies: Lombok, Spring Web, Spring Data JPA, PostgreSQL Driver, Liquibase Migration. Write a Liquibase migration for the tables. Use YAML format for liquibase scripts.
`<table1>`
	Category table with columns: category_id (bigint), category_name (varchar), category_description (varchar)
`</table1>`
`<table2>`
	Operation table with columns: operation_id (bigint), operation_public_id (varchar), operation_name (varchar), operation_amount(bigdecimal), operation_type (enum), category_id (FK to category table)
`</table2>`
Suggest how to store the operation_type. In the code, the operation type will be an Enum with the values (DEPOSIT, WITHDRAW).

I have already created an application using Spring Initializr with the following dependencies: Lombok, Spring Web, Spring Data JPA, PostgreSQL Driver, Liquibase Migration. 
Write a Liquibase migration for the tables. Use YAML format for liquibase scripts. 

`<table1>` 
	Category table with columns: category_id (bigint), 
	category_name (varchar), category_description (varchar) 
`</table1>`
`<table2>`
	Operation table with columns: operation_id (bigint), 
	operation_public_id (varchar), operation_name (varchar), 
	operation_amount(bigdecimal), operation_type (enum), 
	category_id (FK to category table) 
`</table2>` 

Suggest how to store the operation_type. 
In the code, the operation type will be an Enum with the values (DEPOSIT, WITHDRAW).

Thanks for the details! Here's how we'll proceed:

✅ Plan

1. Enum Handling (operation_type)

We’ll store the operation_type enum as a VARCHAR in the database. This approach:

• Keeps the data readable and meaningful.

• Avoids the risks of ordinal-based persistence (i.e., changes in enum order).

• Is compatible with JPA enum mapping using @Enumerated(EnumType.STRING).

2. Liquibase YAML Migration File

We'll write a migration file in YAML that:

• Creates the category table.

• Creates the operation table.

• Defines operation_type as a VARCHAR.

• Sets up a foreign key from operation.category_id to category.category_id.

• Adds primary keys for both tables.

? Liquibase YAML Migration Script

Here's a production-ready db.changelog-1.0.yaml:

databaseChangeLog:
  - changeSet:
      id: 1
      author: backenddev
      changes:
        - createTable:
            tableName: category
            columns:
              - column:
                  name: category_id
                  type: BIGINT
                  constraints:
                    primaryKey: true
                    nullable: false
              - column:
                  name: category_name
                  type: VARCHAR(255)
                  constraints:
                    nullable: false
              - column:
                  name: category_description
                  type: VARCHAR(1000)

  - changeSet:
      id: 2
      author: backenddev
      changes:
        - createTable:
            tableName: operation
            columns:
              - column:
                  name: operation_id
                  type: BIGINT
                  constraints:
                    primaryKey: true
                    nullable: false
              - column:
                  name: operation_public_id
                  type: VARCHAR(255)
                  constraints:
                    nullable: false
                    unique: true
              - column:
                  name: operation_name
                  type: VARCHAR(255)
                  constraints:
                    nullable: false
              - column:
                  name: operation_amount
                  type: NUMERIC(19,2)
                  constraints:
                    nullable: false
              - column:
                  name: operation_type
                  type: VARCHAR(50)
                  constraints:
                    nullable: false
              - column:
                  name: category_id
                  type: BIGINT
                  constraints:
                    nullable: false

        - addForeignKeyConstraint:
            baseTableName: operation
            baseColumnNames: category_id
            referencedTableName: category
            referencedColumnNames: category_id
            constraintName: fk_operation_category

? Enum Mapping in Java (for reference)

In your Operation entity:

@Enumerated(EnumType.STRING)
@Column(name = "operation_type", nullable = false)
private OperationType operationType;

Let me know if you'd like:

• Liquibase rollback support.

• Sample Java entity classes.

• Sample test data insertion via Liquibase.

Shall we move forward with the entity classes or anything else you need help with?

Sure! Here's the standard Spring Boot application configuration for connecting to a PostgreSQL database, including Liquibase support.

✅ application.yml Configuration

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/your_database_name
    username: your_db_username
    password: your_db_password
    driver-class-name: org.postgresql.Driver
  jpa:
    hibernate:
      ddl-auto: none  # Liquibase handles schema creation
    show-sql: true
    properties:
      hibernate:
        dialect: org.hibernate.dialect.PostgreSQLDialect

  liquibase:
    change-log: classpath:db/changelog/db.changelog-1.0.yaml
    enabled: true

# Optional logging for SQL debugging
logging:
  level:
    org.hibernate.SQL: DEBUG
    org.hibernate.type.descriptor.sql: TRACE

✅ Tips

• Replace your_database_name, your_db_username, and your_db_password with your actual PostgreSQL config.

• Make sure your YAML is properly indented and db.changelog-1.0.yaml is placed under src/main/resources/db/changelog/.

Would you like me to generate the corresponding Java entity classes next?

Great question — and no, you don’t need to manually add every migration file to application.yml.

✅ How Liquibase Works in Spring Boot

Liquibase uses a master changelog file (like db.changelog-1.0.yaml) as the entry point. That file can include other changelogs, and Liquibase will process them in order automatically.

? Recommended Setup with Includes

Use a master changelog like this:

db.changelog-master.yaml (referenced in application.yml)

databaseChangeLog:
  - include:
      file: db/changelog/db.changelog-1.0.yaml
  - include:
      file: db/changelog/db.changelog-1.1.yaml
  - include:
      file: db/changelog/db.changelog-1.2.yaml

Then in application.yml:

spring:
  liquibase:
    change-log: classpath:db/changelog/db.changelog-master.yaml

Whenever you add a new migration:

1. Create a new file like db.changelog-1.3.yaml.

2. Add an - include: line for it in the master file.

? Best Practice Tips

• Version your changelog files for clarity (1.0, 1.1, etc.).

• Keep each file focused on a related set of changes.

• Keep the master file clean and ordered by time/version.

Let me know if you want a script or method to auto-include files dynamically, or if you want to switch to XML or SQL format later.

Here's your init.sql script to:

1. Create the chatgpt_4o_app role with login and password.

2. Create the chatgpt_4o schema.

3. Grant usage and privileges on the schema to the role.

✅ init.sql

-- Create application role with login
CREATE ROLE chatgpt_4o_app WITH
  LOGIN
  PASSWORD 'strongPassword';

-- Create schema
CREATE SCHEMA chatgpt_4o AUTHORIZATION chatgpt_4o_app;

-- Grant all privileges on the schema to the role
GRANT ALL PRIVILEGES ON SCHEMA chatgpt_4o TO chatgpt_4o_app;

? Usage Tips

• You can run this manually in your PostgreSQL console or configure it to run automatically using a Docker initdb script if you're using Postgres in Docker.

• Make sure your Spring Boot application.yml points to the chatgpt_4o schema, like this:

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/your_database_name?currentSchema=chatgpt_4o

Let me know if you need a Docker Compose setup for PostgreSQL with this script as part of the initialization.

Here’s how to create clean, production-ready entities for Category and Operation based on your schema and best practices with Spring Boot + JPA + Lombok.

✅ Recommended Package Structure

src/main/java
└── com/yourcompany/yourapp
    └── model
        ├── Category.java
        └── Operation.java
        └── OperationType.java (enum)

Use this path for your entity package:

> com.yourcompany.yourapp.model

You can replace yourcompany and yourapp with your actual organization and application name.

✅ Category.java

package com.yourcompany.yourapp.model;

import jakarta.persistence.*;
import lombok.*;

import java.util.List;

@Entity
@Table(name = "category", schema = "chatgpt_4o")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Category {

    @Id
    @Column(name = "category_id", nullable = false)
    private Long categoryId;

    @Column(name = "category_name", nullable = false)
    private String categoryName;

    @Column(name = "category_description")
    private String categoryDescription;

    @OneToMany(mappedBy = "category", cascade = CascadeType.ALL, orphanRemoval = true)
    private List operations;
}

✅ Operation.java

package com.yourcompany.yourapp.model;

import jakarta.persistence.*;
import lombok.*;

import java.math.BigDecimal;

@Entity
@Table(name = "operation", schema = "chatgpt_4o")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Operation {

    @Id
    @Column(name = "operation_id", nullable = false)
    private Long operationId;

    @Column(name = "operation_public_id", nullable = false, unique = true)
    private String operationPublicId;

    @Column(name = "operation_name", nullable = false)
    private String operationName;

    @Column(name = "operation_amount", nullable = false)
    private BigDecimal operationAmount;

    @Enumerated(EnumType.STRING)
    @Column(name = "operation_type", nullable = false)
    private OperationType operationType;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "category_id", nullable = false)
    private Category category;
}

✅ OperationType.java (Enum)

package com.yourcompany.yourapp.model;

public enum OperationType {
    DEPOSIT,
    WITHDRAW
}

Let me know if you want to:

• Generate DTOs or mappers.

• Add base auditing fields (createdAt, updatedAt, etc.).

• Configure ID generation (UUID, sequence, etc.).

Would you like the repository interfaces next?

Great catch! By default, JPA needs an ID generation strategy for primary keys unless you're assigning them manually. Since operation_id and category_id are of type Long, the most appropriate strategy for PostgreSQL is usually GenerationType.IDENTITY or GenerationType.SEQUENCE.

✅ Recommendation: Use @GeneratedValue(strategy = GenerationType.IDENTITY)

This works well with PostgreSQL's SERIAL or IDENTITY columns and is simple to implement.

✅ Updated Entity Code with ID Generation

? Category.java

package com.yourcompany.yourapp.model;

import jakarta.persistence.*;
import lombok.*;

import java.util.List;

@Entity
@Table(name = "category", schema = "chatgpt_4o")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Category {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "category_id", nullable = false)
    private Long categoryId;

    @Column(name = "category_name", nullable = false)
    private String categoryName;

    @Column(name = "category_description")
    private String categoryDescription;

    @OneToMany(mappedBy = "category", cascade = CascadeType.ALL, orphanRemoval = true)
    private List operations;
}

? Operation.java

package com.yourcompany.yourapp.model;

import jakarta.persistence.*;
import lombok.*;

import java.math.BigDecimal;

@Entity
@Table(name = "operation", schema = "chatgpt_4o")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Operation {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "operation_id", nullable = false)
    private Long operationId;

    @Column(name = "operation_public_id", nullable = false, unique = true)
    private String operationPublicId;

    @Column(name = "operation_name", nullable = false)
    private String operationName;

    @Column(name = "operation_amount", nullable = false)
    private BigDecimal operationAmount;

    @Enumerated(EnumType.STRING)
    @Column(name = "operation_type", nullable = false)
    private OperationType operationType;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "category_id", nullable = false)
    private Category category;
}

? Optional: Liquibase Adjustment

If you're using GenerationType.IDENTITY, update your Liquibase YAML to use:

type: BIGSERIAL

For example:

- column:
    name: category_id
    type: BIGSERIAL
    constraints:
      primaryKey: true
      nullable: false

Let me know if you'd like me to regenerate the Liquibase changelog with BIGSERIAL for these IDs.

Great! Below is a clean, layered implementation of the CREATE operation for the Operation entity using:

• Controller (OperationController)

• Service (OperationService)

• Repository (OperationRepository)

• DTOs (CreateOperationRequest)

• Mapping logic (simple manual mapping)

This implementation skips field validation (as requested) and assumes that the category_id provided in the request already exists.

✅ Recommended Package Structure

com.yourcompany.yourapp
├── controller
│   └── OperationController.java
├── service
│   └── OperationService.java
├── repository
│   └── OperationRepository.java
├── dto
│   └── CreateOperationRequest.java
├── model
│   └── Operation.java
│   └── Category.java
│   └── OperationType.java

? CreateOperationRequest.java

package com.yourcompany.yourapp.dto;

import com.yourcompany.yourapp.model.OperationType;
import lombok.*;

import java.math.BigDecimal;

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class CreateOperationRequest {
    private String operationPublicId;
    private String operationName;
    private BigDecimal operationAmount;
    private OperationType operationType;
    private Long categoryId;
}

? OperationRepository.java

package com.yourcompany.yourapp.repository;

import com.yourcompany.yourapp.model.Operation;
import org.springframework.data.jpa.repository.JpaRepository;

public interface OperationRepository extends JpaRepository {
}

? CategoryRepository.java

package com.yourcompany.yourapp.repository;

import com.yourcompany.yourapp.model.Category;
import org.springframework.data.jpa.repository.JpaRepository;

public interface CategoryRepository extends JpaRepository {
}

? OperationService.java

package com.yourcompany.yourapp.service;

import com.yourcompany.yourapp.dto.CreateOperationRequest;
import com.yourcompany.yourapp.model.Category;
import com.yourcompany.yourapp.model.Operation;
import com.yourcompany.yourapp.repository.CategoryRepository;
import com.yourcompany.yourapp.repository.OperationRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;

@Service
@RequiredArgsConstructor
public class OperationService {

    private final OperationRepository operationRepository;
    private final CategoryRepository categoryRepository;

    public Operation createOperation(CreateOperationRequest request) {
        Category category = categoryRepository.findById(request.getCategoryId())
                .orElseThrow(() -> new RuntimeException("Category not found"));

        Operation operation = Operation.builder()
                .operationId(System.currentTimeMillis()) // Temporary ID generator; replace in production
                .operationPublicId(request.getOperationPublicId())
                .operationName(request.getOperationName())
                .operationAmount(request.getOperationAmount())
                .operationType(request.getOperationType())
                .category(category)
                .build();

        return operationRepository.save(operation);
    }
}

? OperationController.java

package com.yourcompany.yourapp.controller;

import com.yourcompany.yourapp.dto.CreateOperationRequest;
import com.yourcompany.yourapp.model.Operation;
import com.yourcompany.yourapp.service.OperationService;
import lombok.RequiredArgsConstructor;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/operations")
@RequiredArgsConstructor
public class OperationController {

    private final OperationService operationService;

    @PostMapping
    public ResponseEntity createOperation(@RequestBody CreateOperationRequest request) {
        Operation created = operationService.createOperation(request);
        return ResponseEntity.ok(created);
    }
}

? Example POST Request

Endpoint: POST /api/operations
Content-Type: application/json

{
  "operationPublicId": "abc-123",
  "operationName": "Initial Deposit",
  "operationAmount": 1000.00,
  "operationType": "DEPOSIT",
  "categoryId": 1
}

? Next Steps (Optional)

Let me know if you'd like to:

• Add field validations.

• Replace manual ID generation with auto-increment or sequence.

• Implement exception handling (custom errors, validation messages).

• Return a DTO instead of full entity.

Would you like to proceed with any of these enhancements?

Great decision — returning a DTO instead of an entity is best practice to:

• Prevent overexposing your entity structure.

• Maintain version control over your API response models.

• Decouple internal model changes from API contracts.

✅ Step-by-Step Update

We'll introduce a new response DTO called OperationResponse and use it in the controller response.

? OperationResponse.java

package com.yourcompany.yourapp.dto;

import com.yourcompany.yourapp.model.OperationType;
import lombok.*;

import java.math.BigDecimal;

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class OperationResponse {
    private Long operationId;
    private String operationPublicId;
    private String operationName;
    private BigDecimal operationAmount;
    private OperationType operationType;
    private Long categoryId;
}

? Update in OperationService

Update the return type and add mapping logic.

✅ Updated Method in OperationService.java:

import com.yourcompany.yourapp.dto.OperationResponse;

public OperationResponse createOperation(CreateOperationRequest request) {
    Category category = categoryRepository.findById(request.getCategoryId())
            .orElseThrow(() -> new RuntimeException("Category not found"));

    Operation operation = Operation.builder()
            .operationId(System.currentTimeMillis()) // Temporary
            .operationPublicId(request.getOperationPublicId())
            .operationName(request.getOperationName())
            .operationAmount(request.getOperationAmount())
            .operationType(request.getOperationType())
            .category(category)
            .build();

    Operation saved = operationRepository.save(operation);

    return OperationResponse.builder()
            .operationId(saved.getOperationId())
            .operationPublicId(saved.getOperationPublicId())
            .operationName(saved.getOperationName())
            .operationAmount(saved.getOperationAmount())
            .operationType(saved.getOperationType())
            .categoryId(saved.getCategory().getCategoryId())
            .build();
}

? Updated OperationController.java

import com.yourcompany.yourapp.dto.OperationResponse;

@PostMapping
public ResponseEntity createOperation(@RequestBody CreateOperationRequest request) {
    OperationResponse response = operationService.createOperation(request);
    return ResponseEntity.ok(response);
}

Let me know if you'd like:

• To map this via ModelMapper or MapStruct for larger projects.

• To include category name in the response.

• To create a dedicated response wrapper for consistency (ApiResponse, etc.).

Perfect — let's walk through this step by step for the UPDATE logic of the Operation entity. First, I’ll clarify the assumptions and ask a couple of questions to ensure alignment.

✅ Step-by-Step Planning

1. Understanding the update use case

We're adding an endpoint to update an existing Operation based on a client-provided identifier.

Likely flow:

• Receive a PUT request with an operationId (path variable) and update data (request body).

• Find the existing Operation by ID.

• Update the mutable fields (publicId, name, amount, type, categoryId, etc.).

• Save the updated operation and return a DTO.

❓ Questions Before Implementation

To tailor this update logic precisely, I need clarification on the following:

1. Identifier for Update:

Should the operation be updated by:

• operation_id (DB ID — primary key)? (default option, recommended)

• or operation_public_id (external ID)?

? If you expect this API to be public-facing, using operation_public_id might be more appropriate.

2. Partial vs Full Update:

Should the update:

• Be full update (PUT — expects full data and overwrites)?

• Or partial update (PATCH — only updates provided fields)?

? You mentioned skipping validation, so we can start with full update via PUT.

3. Behavior on Missing category_id:

Should we:

• Allow reassignment to a new category?

• Or reject the update if the category is missing?

Please confirm:

✅ Use operation_id in path param
✅ Full update (PUT)
✅ Require category_id and allow category reassignment

Once confirmed, I’ll proceed with the full implementation.

Excellent, thanks for the clarification. Here's our refined plan for implementing the partial update logic using:

• operation_public_id as the lookup key

• PATCH semantics (only update fields provided)

• Rejection if category_id is missing but the user attempts to change the category

✅ Final Update Plan

✅ 1. Endpoint

• Method: PATCH

• Path: /api/operations/{operationPublicId}

✅ 2. Update Flow

• Fetch Operation by operation_public_id

• Check which fields are non-null in the request

• Apply changes selectively

• If categoryId is present:

  • Lookup and assign category

• If categoryId is null but the field is attempted to be changed → reject

• Save and return updated OperationResponse

✅ Implementation

? UpdateOperationRequest.java (new DTO)

package com.yourcompany.yourapp.dto;

import com.yourcompany.yourapp.model.OperationType;
import lombok.*;

import java.math.BigDecimal;

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class UpdateOperationRequest {
    private String operationName;
    private BigDecimal operationAmount;
    private OperationType operationType;
    private Long categoryId;
}

? Reuse OperationResponse.java from earlier

? OperationRepository.java — Add Method

import java.util.Optional;

Optional findByOperationPublicId(String operationPublicId);

? OperationService.java — Add Method

import com.yourcompany.yourapp.dto.UpdateOperationRequest;
import com.yourcompany.yourapp.dto.OperationResponse;

public OperationResponse updateOperation(String publicId, UpdateOperationRequest request) {
    Operation operation = operationRepository.findByOperationPublicId(publicId)
            .orElseThrow(() -> new RuntimeException("Operation not found with publicId: " + publicId));

    if (request.getOperationName() != null) {
        operation.setOperationName(request.getOperationName());
    }

    if (request.getOperationAmount() != null) {
        operation.setOperationAmount(request.getOperationAmount());
    }

    if (request.getOperationType() != null) {
        operation.setOperationType(request.getOperationType());
    }

    if (request.getCategoryId() != null) {
        Category category = categoryRepository.findById(request.getCategoryId())
                .orElseThrow(() -> new RuntimeException("Category not found: " + request.getCategoryId()));
        operation.setCategory(category);
    } else if (request.getCategoryId() == null && requestHasCategoryField(request)) {
        throw new RuntimeException("Category ID is required when updating category");
    }

    Operation saved = operationRepository.save(operation);

    return OperationResponse.builder()
            .operationId(saved.getOperationId())
            .operationPublicId(saved.getOperationPublicId())
            .operationName(saved.getOperationName())
            .operationAmount(saved.getOperationAmount())
            .operationType(saved.getOperationType())
            .categoryId(saved.getCategory().getCategoryId())
            .build();
}

// Utility to detect if categoryId was intentionally included
private boolean requestHasCategoryField(UpdateOperationRequest request) {
    try {
        return UpdateOperationRequest.class.getDeclaredField("categoryId") != null;
    } catch (NoSuchFieldException e) {
        return false;
    }
}

? OperationController.java — Add Endpoint

import com.yourcompany.yourapp.dto.UpdateOperationRequest;
import com.yourcompany.yourapp.dto.OperationResponse;

@PatchMapping("/{operationPublicId}")
public ResponseEntity updateOperation(
        @PathVariable String operationPublicId,
        @RequestBody UpdateOperationRequest request
) {
    OperationResponse response = operationService.updateOperation(operationPublicId, request);
    return ResponseEntity.ok(response);
}

✅ Example Request

PATCH /api/operations/abc-123

{
  "operationAmount": 450.75,
  "operationType": "WITHDRAW"
}

This will only update amount and type.

Would you like help adding:

• Field validation (e.g., amount must be > 0)?

• Custom exception classes for better error responses?

• Unit tests for the service layer?

Let me know how you'd like to proceed.

You're absolutely right — using RuntimeException here is too generic and inappropriate for signaling client-side errors (like bad input). We should introduce a custom exception, e.g. BadRequestException, that we can later handle in a global exception handler to return a proper HTTP 400 Bad Request.

✅ Step-by-Step Solution

1. Define a custom exception: BadRequestException

2. Throw it when business logic detects a client error

3. (Optional future step) Catch it in @ControllerAdvice for 400 response

? BadRequestException.java

Create it in:

> com.yourcompany.yourapp.exception

package com.yourcompany.yourapp.exception;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(HttpStatus.BAD_REQUEST)
public class BadRequestException extends RuntimeException {
    public BadRequestException(String message) {
        super(message);
    }
}

• This annotation ensures Spring automatically returns 400 unless you override with @ControllerAdvice.

✅ Update OperationService.java

Replace this:

throw new RuntimeException("Category ID is required when updating category");

With:

throw new BadRequestException("Category ID is required when updating category");

Also replace the similar exception for "Category not found" if it's due to bad client input.

✅ Optional (Advanced): Use Global Exception Handler

Later, you can handle all custom exceptions cleanly with:

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(BadRequestException.class)
    public ResponseEntity> handleBadRequest(BadRequestException ex) {
        return ResponseEntity
            .badRequest()
            .body(Map.of("error", ex.getMessage()));
    }
}

Let me know if you'd like help:

• Creating NotFoundException, ConflictException, etc.

• Designing a full structured error response (timestamp, path, etc.).

• Writing tests for this exception flow.

Great — here's how we'll approach the FIND logic for the Operation entity.

✅ Step-by-Step Breakdown

? Goals

Implement two endpoints:

1. Find all operations (paginated)

2. Find operation by operationPublicId

? Assumptions (Let me know if you want changes)

• Find all will be accessible via GET /api/operations, using query params page and size.

• Default sort: descending by operationId (can be updated later).

• If operationPublicId is not found → return 404 Not Found.

✅ Plan Summary

Do you want:

1. Filtering by category, type, or name in the list endpoint?

2. Sorting support on the findAll endpoint?

If not, I’ll proceed with the basic paginated + publicId lookup implementation. Please confirm or extend the requirement.

Perfect — thanks for confirming. We’ll now implement:

✅ Final Plan

Endpoints:

1. GET /api/operations
   → Returns paged, sorted (desc by operationId) list of operations.

2. GET /api/operations/{operationPublicId}
   → Returns single operation by publicId. Returns 404 if not found.

✅ Implementation Outline

? repository/OperationRepository.java

import com.yourcompany.yourapp.model.Operation;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.Optional;

public interface OperationRepository extends JpaRepository {
    Optional findByOperationPublicId(String operationPublicId);
}

? service/OperationService.java

import com.yourcompany.yourapp.dto.OperationResponse;
import com.yourcompany.yourapp.exception.NotFoundException;
import com.yourcompany.yourapp.model.Operation;
import com.yourcompany.yourapp.repository.OperationRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.data.domain.*;
import org.springframework.stereotype.Service;

import java.util.stream.Collectors;

@Service
@RequiredArgsConstructor
public class OperationService {

    private final OperationRepository operationRepository;

    public Page findAllOperations(int page, int size) {
        Pageable pageable = PageRequest.of(page, size, Sort.by(Sort.Direction.DESC, "operationId"));
        Page operations = operationRepository.findAll(pageable);

        return operations.map(this::toDto);
    }

    public OperationResponse findByPublicId(String publicId) {
        Operation operation = operationRepository.findByOperationPublicId(publicId)
                .orElseThrow(() -> new NotFoundException("Operation not found with publicId: " + publicId));
        return toDto(operation);
    }

    private OperationResponse toDto(Operation operation) {
        return OperationResponse.builder()
                .operationId(operation.getOperationId())
                .operationPublicId(operation.getOperationPublicId())
                .operationName(operation.getOperationName())
                .operationAmount(operation.getOperationAmount())
                .operationType(operation.getOperationType())
                .categoryId(operation.getCategory().getCategoryId())
                .build();
    }
}

? controller/OperationController.java

import com.yourcompany.yourapp.dto.OperationResponse;
import com.yourcompany.yourapp.service.OperationService;
import lombok.RequiredArgsConstructor;
import org.springframework.data.domain.Page;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/operations")
@RequiredArgsConstructor
public class OperationController {

    private final OperationService operationService;

    @GetMapping
    public ResponseEntity> findAllOperations(
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "10") int size
    ) {
        return ResponseEntity.ok(operationService.findAllOperations(page, size));
    }

    @GetMapping("/{operationPublicId}")
    public ResponseEntity findByPublicId(
            @PathVariable String operationPublicId
    ) {
        return ResponseEntity.ok(operationService.findByPublicId(operationPublicId));
    }
}

❗ Optional: NotFoundException.java

Create under: exception/NotFoundException.java

package com.yourcompany.yourapp.exception;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(HttpStatus.NOT_FOUND)
public class NotFoundException extends RuntimeException {
    public NotFoundException(String message) {
        super(message);
    }
}

✅ Example Usage

1. Find All (Paginated, Sorted)

GET /api/operations?page=0&size=5

2. Find by Public ID

GET /api/operations/abc-123

Let me know if you’d like:

• Total count & paging metadata wrapped in a custom response.

• Filtering by operationType, categoryId, etc.

• HATEOAS-style links for navigation.

Would you like to proceed with test cases or enhancements next?

Great — here’s a clean implementation of the DELETE logic for the Operation entity using operationPublicId as the lookup key.

✅ Summary

? Requirements

• Delete by operationPublicId

• Skip field validation for now

• Return HTTP 204 No Content on success

• Return HTTP 404 Not Found if not found

✅ Implementation

? OperationRepository.java

No changes needed (already has findByOperationPublicId)

❗ NotFoundException.java

Already exists — reused to return 404

? OperationService.java — Add delete method

public void deleteByPublicId(String publicId) {
    Operation operation = operationRepository.findByOperationPublicId(publicId)
            .orElseThrow(() -> new NotFoundException("Operation not found with publicId: " + publicId));

    operationRepository.delete(operation);
}

? OperationController.java — Add endpoint

@DeleteMapping("/{operationPublicId}")
public ResponseEntity deleteByPublicId(@PathVariable String operationPublicId) {
    operationService.deleteByPublicId(operationPublicId);
    return ResponseEntity.noContent().build();
}

✅ Resulting Behavior

? Request

DELETE /api/operations/abc-123

✅ Success Response

204 No Content

❌ Not Found

404 Not Found
{
  "error": "Operation not found with publicId: abc-123"
}

Let me know if you'd like:

• Soft deletes (e.g., deleted_at column)

• Deletion protection (e.g., prevent delete for DEPOSIT operations)

• Audit logging

Would you like to proceed with testing or add bulk delete support next?

This is how the create operation logic is currently implemented.

Context

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class CreateOperationRequest {
    private String operationName;
    private BigDecimal operationAmount;
    private OperationType operationType;
    private Long categoryId;
}

@RestController
@RequestMapping("/api/operations")
@RequiredArgsConstructor
public class OperationController {

    private final OperationService operationService;

    @PostMapping
    public ResponseEntity createOperation(@RequestBody CreateOperationRequest request) {
        var created = operationService.createOperation(request);
        return ResponseEntity.ok(created);
    }
}

@Service
@RequiredArgsConstructor
public class OperationService {

    private final OperationRepository operationRepository;
    private final CategoryRepository categoryRepository;

    public OperationResponse createOperation(CreateOperationRequest request) {
        Category category = categoryRepository.findById(request.getCategoryId())
                .orElseThrow(() -> new BadRequestException("Category not found"));

        Operation operation = Operation.builder()
                .publicId(UUID.randomUUID().toString())
                .name(request.getOperationName())
                .amount(request.getOperationAmount())
                .type(request.getOperationType())
                .category(category)
                .build();

        var saved = operationRepository.save(operation);
        return toDto(saved);
    }

    private OperationResponse toDto(Operation operation) {
        return OperationResponse.builder()
                .operationId(operation.getId())
                .operationPublicId(operation.getPublicId())
                .operationName(operation.getName())
                .operationAmount(operation.getAmount())
                .operationType(operation.getType())
                .categoryId(operation.getCategory().getId())
                .build();
    }
}

@Entity
@Table(name = "operation", schema = "chatgpt_4o")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Operation {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "operation_id", nullable = false)
    private Long id;

    @Column(name = "operation_public_id", nullable = false, unique = true)
    private String publicId;

    @Column(name = "operation_name", nullable = false)
    private String name;

    @Column(name = "operation_amount", nullable = false)
    private BigDecimal amount;

    @Enumerated(EnumType.STRING)
    @Column(name = "operation_type", nullable = false)
    private OperationType type;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "category_id", nullable = false)
    private Category category;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Operation operation)) return false;
        return id != null && id.equals(operation.id);
    }

    @Override
    public int hashCode() {
        return id != null ? id.hashCode() : super.hashCode();
    }
}

Question

Add validation for "create operation" logic.

Think step by step. If you have any questions, ask them first.

Perfect — thanks for the confirmation.

We'll now implement full validation for the Create Operation flow using:

• jakarta.validation annotations

• @Valid in the controller

• A custom global exception handler to return a structured 400 response

✅ Step 1: Add Validation to CreateOperationRequest

package com.yourcompany.yourapp.dto;

import com.yourcompany.yourapp.model.OperationType;
import jakarta.validation.constraints.*;
import lombok.*;

import java.math.BigDecimal;

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class CreateOperationRequest {

    @NotBlank(message = "Operation name is required")
    @Size(max = 255, message = "Operation name must not exceed 255 characters")
    private String operationName;

    @NotNull(message = "Amount is required")
    @DecimalMin(value = "0.01", inclusive = true, message = "Amount must be greater than 0")
    private BigDecimal operationAmount;

    @NotNull(message = "Operation type is required")
    private OperationType operationType;

    @NotNull(message = "Category ID is required")
    private Long categoryId;
}

✅ Step 2: Enable Validation in OperationController

Update the controller method to use @Valid:

@PostMapping
public ResponseEntity createOperation(@RequestBody @Valid CreateOperationRequest request) {
    var created = operationService.createOperation(request);
    return ResponseEntity.ok(created);
}

✅ Step 3: Add Global Exception Handler for Validation Errors

Create a new class:

> exception/GlobalExceptionHandler.java

package com.yourcompany.yourapp.exception;

import jakarta.validation.ConstraintViolationException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.*;

import java.util.HashMap;
import java.util.Map;

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity> handleValidationErrors(MethodArgumentNotValidException ex) {
        Map errors = new HashMap<>();

        ex.getBindingResult().getFieldErrors().forEach(fieldError -> {
            errors.put(fieldError.getField(), fieldError.getDefaultMessage());
        });

        Map response = new HashMap<>();
        response.put("status", 400);
        response.put("error", "Bad Request");
        response.put("message", "Validation failed");
        response.put("errors", errors);

        return ResponseEntity.badRequest().body(response);
    }
}

✅ Example Response

❌ POST /api/operations with invalid data:

{
  "operationAmount": -5,
  "operationType": null,
  "categoryId": null
}

✅ Response: 400 Bad Request

{
  "status": 400,
  "error": "Bad Request",
  "message": "Validation failed",
  "errors": {
    "operationName": "Operation name is required",
    "operationAmount": "Amount must be greater than 0",
    "operationType": "Operation type is required",
    "categoryId": "Category ID is required"
  }
}

Let me know if you want:

• To add constraints to prevent duplicate operationPublicId (custom validator)

• To group validation messages under error codes for frontend mapping

• To extend the same pattern to Update logic

Would you like me to update the PATCH/UPDATE logic with validation next?

Thanks for the update — when validation annotations are ignored, it usually comes down to one of the following 3 root causes in Spring Boot.

Let’s diagnose and fix this step by step.

✅ 1. @Valid Annotation Must Be on the Controller Parameter

Problem: The controller method is missing @Valid.

Fix: Ensure your controller method looks like this:

@PostMapping
public ResponseEntity createOperation(@RequestBody @Valid CreateOperationRequest request) {
    var created = operationService.createOperation(request);
    return ResponseEntity.ok(created);
}

⚠️ If @Valid is missing, Spring will not trigger validation even if annotations are present in the DTO.

✅ 2. You Must Be Using jakarta.validation (Correct Import)

Problem: You're importing validation annotations from javax.validation in a Spring Boot 3+ project, which uses Jakarta EE 10.

Fix:

Make sure these are your imports:

import jakarta.validation.constraints.NotBlank;
import jakarta.validation.constraints.NotNull;
import jakarta.validation.constraints.DecimalMin;
import jakarta.validation.Valid;

If you're mixing javax and jakarta, validation will silently fail.

✅ 3. The Validation Starter Must Be on the Classpath

Problem: Missing dependency.

Fix: Ensure your pom.xml includes this starter:

  org.springframework.boot
  spring-boot-starter-validation

This starter pulls in Jakarta Bean Validation support.

✅ Recap: Do These 3 Things

• Use @Valid in the controller: @RequestBody @Valid CreateOperationRequest

• Use jakarta.validation.* annotations in the DTO

• Add spring-boot-starter-validation to your dependencies

Would you like me to review your pom.xml or controller code if the issue persists after checking these?

This is a reminder of the code contained in the OperationService class:

@Service
@RequiredArgsConstructor
public class OperationService {

    private final OperationRepository operationRepository;
    private final CategoryRepository categoryRepository;

    public OperationResponse createOperation(CreateOperationRequest request) {
        Category category = categoryRepository.findById(request.getCategoryId())
                .orElseThrow(() -> new BadRequestException("Category not found"));

        Operation operation = Operation.builder()
                .publicId(UUID.randomUUID().toString())
                .name(request.getOperationName())
                .amount(request.getOperationAmount())
                .type(request.getOperationType())
                .category(category)
                .build();

        var saved = operationRepository.save(operation);
        return toDto(saved);
    }

    public OperationResponse updateOperation(String publicId, UpdateOperationRequest request) {
        Operation operation = operationRepository.findOperationByPublicId(publicId)
                .orElseThrow(() -> new BadRequestException("Operation not found with publicId: " + publicId));

        if (request.getOperationName() != null) {
            operation.setName(request.getOperationName());
        }

        if (request.getOperationAmount() != null) {
            operation.setAmount(request.getOperationAmount());
        }

        if (request.getOperationType() != null) {
            operation.setType(request.getOperationType());
        }

        if (request.getCategoryId() != null) {
            Category category = categoryRepository.findById(request.getCategoryId())
                    .orElseThrow(() -> new BadRequestException("Category not found: " + request.getCategoryId()));
            operation.setCategory(category);
        } else if (request.getCategoryId() == null) {
            throw new BadRequestException("Category ID is required when updating category");
        }

        Operation saved = operationRepository.save(operation);

        return toDto(saved);
    }

    public Page findAllOperations(int page, int size) {
        var pageable = PageRequest.of(page, size, Sort.by(Sort.Direction.DESC, "id"));
        Page operations = operationRepository.findAll(pageable);

        return operations.map(this::toDto);
    }

    public OperationResponse findByPublicId(String publicId) {
        Operation operation = operationRepository.findOperationByPublicId(publicId)
                .orElseThrow(() -> new NotFoundException("Operation not found with publicId: " + publicId));
        return toDto(operation);
    }

    public void deleteByPublicId(String publicId) {
        Operation operation = operationRepository.findOperationByPublicId(publicId)
                .orElseThrow(() -> new NotFoundException("Operation not found with publicId: " + publicId));
    
        operationRepository.delete(operation);
    }

    private OperationResponse toDto(Operation operation) {
        return OperationResponse.builder()
                .operationId(operation.getId())
                .operationPublicId(operation.getPublicId())
                .operationName(operation.getName())
                .operationAmount(operation.getAmount())
                .operationType(operation.getType())
                .categoryId(operation.getCategory().getId())
                .build();
    }
}

Write unit-tests for OperationService. You should write positive and negative tests where it's needed (for example: check that an exception will be thrown)

Perfect — let’s create unit tests for OperationService, covering both positive and negative paths.

✅ Tools & Setup

We’ll use:

• JUnit 5

• Mockito (@Mock, @InjectMocks)

• @ExtendWith(MockitoExtension.class)

✅ Test Cases to Cover

✅ Test File: OperationServiceTest.java

package com.yourcompany.yourapp.service;

import com.yourcompany.yourapp.dto.CreateOperationRequest;
import com.yourcompany.yourapp.dto.UpdateOperationRequest;
import com.yourcompany.yourapp.exception.BadRequestException;
import com.yourcompany.yourapp.exception.NotFoundException;
import com.yourcompany.yourapp.model.*;
import com.yourcompany.yourapp.repository.CategoryRepository;
import com.yourcompany.yourapp.repository.OperationRepository;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;

import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import org.springframework.data.domain.*;

import java.math.BigDecimal;
import java.util.*;

import static org.assertj.core.api.Assertions.*;
import static org.mockito.Mockito.*;

@ExtendWith(MockitoExtension.class)
class OperationServiceTest {

    @Mock private OperationRepository operationRepository;
    @Mock private CategoryRepository categoryRepository;

    @InjectMocks private OperationService operationService;

    private Category category;
    private Operation operation;

    @BeforeEach
    void setUp() {
        category = Category.builder().id(1L).name("Test Category").build();
        operation = Operation.builder()
                .id(1L)
                .publicId("uuid-123")
                .name("Test Operation")
                .amount(BigDecimal.valueOf(100))
                .type(OperationType.DEPOSIT)
                .category(category)
                .build();
    }

    // --- CREATE ---

    @Test
    void createOperation_success() {
        var request = CreateOperationRequest.builder()
                .operationName("Create")
                .operationAmount(BigDecimal.TEN)
                .operationType(OperationType.DEPOSIT)
                .categoryId(1L)
                .build();

        when(categoryRepository.findById(1L)).thenReturn(Optional.of(category));
        when(operationRepository.save(any())).thenReturn(operation);

        var response = operationService.createOperation(request);

        assertThat(response).isNotNull();
        assertThat(response.getOperationName()).isEqualTo("Test Operation");
        verify(operationRepository).save(any());
    }

    @Test
    void createOperation_categoryNotFound_throwsBadRequest() {
        var request = CreateOperationRequest.builder()
                .categoryId(999L)
                .operationAmount(BigDecimal.TEN)
                .operationName("Invalid")
                .operationType(OperationType.DEPOSIT)
                .build();

        when(categoryRepository.findById(999L)).thenReturn(Optional.empty());

        assertThatThrownBy(() -> operationService.createOperation(request))
                .isInstanceOf(BadRequestException.class)
                .hasMessageContaining("Category not found");
    }

    // --- UPDATE ---

    @Test
    void updateOperation_success() {
        var request = UpdateOperationRequest.builder()
                .operationName("Updated")
                .operationAmount(BigDecimal.valueOf(999))
                .operationType(OperationType.WITHDRAW)
                .categoryId(1L)
                .build();

        when(operationRepository.findOperationByPublicId("uuid-123")).thenReturn(Optional.of(operation));
        when(categoryRepository.findById(1L)).thenReturn(Optional.of(category));
        when(operationRepository.save(any())).thenReturn(operation);

        var result = operationService.updateOperation("uuid-123", request);

        assertThat(result.getOperationAmount()).isEqualTo(BigDecimal.valueOf(100)); // from setup
        verify(operationRepository).save(any());
    }

    @Test
    void updateOperation_operationNotFound_throwsBadRequest() {
        when(operationRepository.findOperationByPublicId("missing")).thenReturn(Optional.empty());

        assertThatThrownBy(() -> operationService.updateOperation("missing", new UpdateOperationRequest()))
                .isInstanceOf(BadRequestException.class)
                .hasMessageContaining("Operation not found");
    }

    @Test
    void updateOperation_categoryIdMissing_throwsBadRequest() {
        var request = UpdateOperationRequest.builder().categoryId(null).build();
        when(operationRepository.findOperationByPublicId("uuid-123")).thenReturn(Optional.of(operation));

        assertThatThrownBy(() -> operationService.updateOperation("uuid-123", request))
                .isInstanceOf(BadRequestException.class)
                .hasMessageContaining("Category ID is required");
    }

    @Test
    void updateOperation_categoryNotFound_throwsBadRequest() {
        var request = UpdateOperationRequest.builder().categoryId(99L).build();

        when(operationRepository.findOperationByPublicId("uuid-123")).thenReturn(Optional.of(operation));
        when(categoryRepository.findById(99L)).thenReturn(Optional.empty());

        assertThatThrownBy(() -> operationService.updateOperation("uuid-123", request))
                .isInstanceOf(BadRequestException.class)
                .hasMessageContaining("Category not found");
    }

    // --- FIND ONE ---

    @Test
    void findByPublicId_success() {
        when(operationRepository.findOperationByPublicId("uuid-123")).thenReturn(Optional.of(operation));

        var result = operationService.findByPublicId("uuid-123");

        assertThat(result.getOperationName()).isEqualTo("Test Operation");
    }

    @Test
    void findByPublicId_notFound_throwsNotFound() {
        when(operationRepository.findOperationByPublicId("missing")).thenReturn(Optional.empty());

        assertThatThrownBy(() -> operationService.findByPublicId("missing"))
                .isInstanceOf(NotFoundException.class);
    }

    // --- FIND ALL ---

    @Test
    void findAllOperations_success() {
        var page = new PageImpl<>(List.of(operation));
        when(operationRepository.findAll(any(Pageable.class))).thenReturn(page);

        var result = operationService.findAllOperations(0, 10);

        assertThat(result.getContent()).hasSize(1);
    }

    // --- DELETE ---

    @Test
    void deleteByPublicId_success() {
        when(operationRepository.findOperationByPublicId("uuid-123")).thenReturn(Optional.of(operation));

        operationService.deleteByPublicId("uuid-123");

        verify(operationRepository).delete(operation);
    }

    @Test
    void deleteByPublicId_notFound_throwsNotFound() {
        when(operationRepository.findOperationByPublicId("missing")).thenReturn(Optional.empty());

        assertThatThrownBy(() -> operationService.deleteByPublicId("missing"))
                .isInstanceOf(NotFoundException.class);
    }
}

✅ Notes

• Uses Mockito for mocking repositories.

• Uses AssertJ (assertThat, assertThatThrownBy) for fluent assertions.

• Covers all critical success and failure paths.

Would you like:

• Integration tests for controller endpoints (@WebMvcTest)?

• Test coverage for GlobalExceptionHandler?

• MockMvc or RestAssured tests with Spring Boot Test?

Let me know how you'd like to extend your test coverage.