Update README.md

Author: malczuuu

README.md

@@ -49,24 +49,24 @@ import org.springframework.web.context.request.WebRequest;
 @RestControllerAdvice
 public class ExampleExceptionAdvice {
 
-    @ExceptionHandler(ExampleException.class)
-    public ResponseEntity<Problem> method(ExampleException ex, WebRequest request) {
-        Problem problem =
-                Problem.builder()
-                        .type("http://example.com/errors/example-error")
-                        .title("Example Title")
-                        .status(400)
-                        .detail(ex.getMessage())
-                        .instance("https://example.com/instances/example-instance")
-                        .build();
-
-        HttpHeaders headers = new HttpHeaders();
-        headers.setContentType(MediaType.APPLICATION_PROBLEM_JSON);
-
-        HttpStatus status = HttpStatus.valueOf(problem.getStatus());
-
-        return new ResponseEntity<>(problem, headers, status);
-    }
+  @ExceptionHandler(ExampleException.class)
+  public ResponseEntity<Problem> method(ExampleException ex, WebRequest request) {
+    Problem problem =
+        Problem.builder()
+            .type("http://example.com/errors/example-error")
+            .title("Example Title")
+            .status(400)
+            .detail(ex.getMessage())
+            .instance("https://example.com/instances/example-instance")
+            .build();
+
+    HttpHeaders headers = new HttpHeaders();
+    headers.setContentType(MediaType.APPLICATION_PROBLEM_JSON);
+
+    HttpStatus status = HttpStatus.valueOf(problem.getStatus());
+
+    return new ResponseEntity<>(problem, headers, status);
+  }
 }
 ```
 

problem4j-spring-web/README.md

@@ -1,4 +1,15 @@
-# Built-in Spring Exception Mappings
+# Mapping exceptions to `application/problem+json` responses
+
+1. [Overview](#overview)
+2. [Returning response bodies from custom exceptions](#returning-response-bodies-from-custom-exceptions)
+    1. [Extending `ProblemException`](#extending-problemexception)
+    2. [Annotating `@ProblemMapping`](#annotating-problemmapping)
+3. [Validation](#validation)
+4. [Occurrences of `TypeMismatchException`](#occurrences-of-typemismatchexception)
+5. [Occurrences of `ErrorResponseException`](#occurrences-of-errorresponseexception)
+6. [General HTTP Stuff](#general-http-stuff)
+
+## Overview
 
 This module overrides Spring Web's default (often minimal or plain-text) responses for many framework exceptions and
 produces structured RFC 7807 `Problem` objects. [`ExceptionMappingConfiguration`][ExceptionMappingConfiguration]
@@ -67,7 +78,7 @@ To extract values from target exception, it's possible to use placeholders for i
 
 ```java
 /**
-  * <pre>{@code
+ * <pre>{@code
  * {
  *   "type": "https://example.com/errors/invalid-request",
  *   "title": "Invalid Request",
@@ -127,7 +138,9 @@ property `spring.validation.method.adapt-constraint-violations` to `true`. Enabl
 not rely on raw `ConstraintViolationException`, but rather on `MethodValidationException`, which contains more details
 about validated element.
 
-Let's say we have following `@RestController`, where `idx` query param has different Java parameter name.
+Let's say we have following `@RestController`, where `customerId` query param has different Java parameter name (its
+`String customerIdParam`). We would like to have `customerId` in our response body as potential API clients do not have
+knowledge about internal technologies used by backend.
 
 ```java
 @Validated
@@ -175,6 +188,8 @@ or not. For `true` it will use value from `@RequestParam` (if able) (the same go
 </tr>
 </table>
 
+*Note* that this is not build-in behaviour. It was implemented in [`MethodValidationMapping`][MethodValidationMapping].
+
 ## Occurrences of `TypeMismatchException`
 
 Triggered for example when trying to pass `String` value into `@RequestParam("param") Integer param`.
@@ -240,7 +255,7 @@ Example:
    }
    ```
 5. If passing request that's too large by configuration, service will write following response. Note that reason phrase
-   for `413` was changed into `Content Too Large` in [RFC 9110 §15.5.14][rfc9110-15.5.4]. 
+   for `413` was changed into `Content Too Large` in [RFC 9110 §15.5.14][rfc9110-15.5.4].
    ```json
    {
      "status": 413,
@@ -253,3 +268,5 @@ Example:
 [ExceptionMapping]: src/main/java/io/github/malczuuu/problem4j/spring/web/mapping/ExceptionMapping.java
 
 [ExceptionMappingConfiguration]: src/main/java/io/github/malczuuu/problem4j/spring/web/mapping/ExceptionMappingConfiguration.java
+
+[MethodValidationMapping]: src/main/java/io/github/malczuuu/problem4j/spring/web/mapping/MethodValidationMapping.java

problem4j-spring-webflux/README.md

@@ -16,6 +16,8 @@ RFC 7807 `Problem` objects, with exceptions that are specific to `spring-webflux
 8. What happens if HTTP method (`GET`,`POST`, etc.) is invalid - [`MethodNotAllowedTest`][MethodNotAllowedTest].
 9. What happens if unknown endpoint (or resource) is accessed - [`NotFoundTest`][NotFoundTest].
 10. What happens if `ErrorResponseException` is thrown - [`ErrorResponseTest`][ErrorResponseTest].
+11. What happens if `ProblemException` is thrown [`ProblemFluxAdviceTest`][ProblemFluxAdviceTest] (or exception
+    annotated with`@ProblemMapping`).
 
 [MissingParameterTest]: src/test/java/io/github/malczuuu/problem4j/spring/webflux/integration/MissingParameterTest.java
 
@@ -36,3 +38,5 @@ RFC 7807 `Problem` objects, with exceptions that are specific to `spring-webflux
 [NotFoundTest]: src/test/java/io/github/malczuuu/problem4j/spring/webflux/integration/NotFoundTest.java
 
 [ErrorResponseTest]: src/test/java/io/github/malczuuu/problem4j/spring/webflux/integration/ErrorResponseTest.java
+
+[ProblemFluxAdviceTest]: src/test/java/io/github/malczuuu/problem4j/spring/webflux/integration/ProblemFluxAdviceTest.java

problem4j-spring-webmvc/README.md

@@ -31,6 +31,8 @@ controller never leaks.
 8. What happens if HTTP method (`GET`,`POST`, etc.) is invalid - [`MethodNotAllowedTest`][MethodNotAllowedTest].
 9. What happens if unknown endpoint (or resource) is accessed - [`NotFoundTest`][NotFoundTest].
 10. What happens if `ErrorResponseException` is thrown - [`ErrorResponseTest`][ErrorResponseTest].
+11. What happens if `ProblemException` is thrown [`ProblemMvcAdviceTest`][ProblemMvcAdviceTest] (or exception
+    annotated with`@ProblemMapping`).
 
 [MissingParameterTest]: src/test/java/io/github/malczuuu/problem4j/spring/webmvc/integration/MissingParameterTest.java
 
@@ -51,3 +53,5 @@ controller never leaks.
 [NotFoundTest]: src/test/java/io/github/malczuuu/problem4j/spring/webmvc/integration/NotFoundTest.java
 
 [ErrorResponseTest]: src/test/java/io/github/malczuuu/problem4j/spring/webmvc/integration/ErrorResponseTest.java
+
+[ProblemMvcAdviceTest]: src/test/java/io/github/malczuuu/problem4j/spring/webmvc/integration/ProblemMvcAdviceTest.java