What is the use of @ApiModel annotation?

The @ApiModel annotation in Swagger (now OpenAPI) is primarily used to provide additional, descriptive information and metadata about a data model. This model typically represents a Java class or object that serves as a data structure in your API's requests or responses.

What is the Use of @ApiModel Annotation?

The @ApiModel annotation is a crucial component of Swagger's documentation capabilities, enhancing the clarity and comprehensibility of your API's data models for consumers. When Swagger tools process your codebase, this annotation helps generate a more detailed and user-friendly OpenAPI specification for your data structures.

Key Purposes and Benefits

Using @ApiModel allows you to override default names and add descriptions, making your API documentation more intuitive and easier to navigate:

• Customizing Model Name: By default, Swagger uses the class name as the model's name in the documentation. @ApiModel allows you to define a more readable or specific name (e.g., changing UserDTO to UserProfile).
• Adding Model Description: You can provide a comprehensive, high-level explanation of what the model represents, its purpose, and its overall structure. This helps API consumers quickly grasp the significance of a particular data type.
• Improving Readability and Comprehension: Well-documented models reduce ambiguity and make it simpler for developers consuming your API to understand the expected data formats and their meaning.

Practical Example

Consider a scenario where you have a Java class representing product details. Without @ApiModel, Swagger might just display Product with its properties. With the annotation, you can enrich this:

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;

@ApiModel(value = "ProductDetails", description = "Represents a complete product item with all its attributes in the inventory system.")
public class Product {

    @ApiModelProperty(value = "Unique identifier of the product", example = "PROD001")
    private String productId;

    @ApiModelProperty(value = "Name of the product", example = "Laptop Pro")
    private String name;

    @ApiModelProperty(value = "Current price of the product", example = "1200.00")
    private double price;

    // Getters and setters
}

In this example:

• value = "ProductDetails" renames the model from Product to ProductDetails in the Swagger UI.
• description = "Represents a complete product item..." provides a detailed overview of the Product model itself.

Relationship with Other Swagger Annotations

@ApiModel focuses on the model (class) level. It often works in conjunction with other Swagger annotations to provide a complete picture:

Annotation	Description	Purpose
@ApiModel	Provides additional information about Swagger models.	Describes the entire data structure (class).
@ApiModelProperty	Adds and manipulates data of a model property.	Describes individual fields/properties within a data structure.
@ApiOperation	Describes an operation or typically a HTTP method against a specific path.	Documents API endpoints (e.g., GET, POST, PUT, DELETE operations).
@ApiParam	Adds additional meta-data for operation parameters.	Documents parameters of an API operation (e.g., path variables, query parameters).

By leveraging @ApiModel alongside other annotations, developers can create comprehensive, machine-readable API documentation that clearly outlines all aspects of their API's operations and data structures.