MatrixVariable class

Binds a matrix variable from a specific path segment of the URI to a method parameter.

Matrix variables are key-value pairs embedded in URI path segments using semicolon syntax. They provide a way to attach metadata to individual path segments in a RESTful URL structure.

Matrix Variable Syntax

/resources/{id};key=value/other;param=42

Parameters

• value: Name of the matrix variable to bind
• pathVar: The name of the path variable segment containing the matrix variable
• required: Whether this variable is mandatory (default: true)
• defaultValue: Fallback value if the matrix variable is missing

Example

@RestController()
class ProductController {
  @GetMapping('/products/{category}/items/{id}')
  Product getProduct(
    @MatrixVariable(value: 'sort', pathVar: 'category') String sortBy,
    @MatrixVariable(value: 'version', pathVar: 'id', required: false) String? version
  ) {
    // URL: /products/electronics;sort=price/items/123;version=2
    // sortBy = "price", version = "2"
    return productService.findProduct(sortBy: sortBy, version: version);
  }
}

Framework Integration

This annotation is processed by the MatrixVariableResolver which extracts matrix variables from the appropriate path segments.

Related Components

• MatrixVariableResolver - The resolver implementation for this annotation
• MatrixVariables - Data structure holding resolved matrix variables
• MatrixVariableUtils - Parser for extracting matrix variables from URIs