fix: guard ValidPageable validator against Pageable.unpaged()

   Calling getPageSize()/getPageNumber() on Pageable.unpaged() throws
   UnsupportedOperationException. Add an isPaged() check so unpaged
   requests pass validation without error.

Author: Picazsoo

modules/openapi-generator/src/main/resources/JavaSpring/validPageable.mustache

@@ -66,6 +66,10 @@ public @interface ValidPageable {
                 return true;
             }
 
+            if (!pageable.isPaged()) {
+                return true;
+            }
+
             boolean valid = true;
             context.disableDefaultConstraintViolation();
 

modules/openapi-generator/src/main/resources/kotlin-spring/validPageable.mustache

@@ -53,6 +53,7 @@ class PageableConstraintValidator : ConstraintValidator<ValidPageable, Pageable>
 
     override fun isValid(pageable: Pageable?, context: ConstraintValidatorContext): Boolean {
         if (pageable == null) return true
+        if (!pageable.isPaged) return true
 
         var valid = true
         context.disableDefaultConstraintViolation()

samples/server/petstore/kotlin-springboot-sort-validation/src/main/kotlin/org/openapitools/configuration/ValidPageable.kt

@@ -53,6 +53,7 @@ class PageableConstraintValidator : ConstraintValidator<ValidPageable, Pageable>
 
     override fun isValid(pageable: Pageable?, context: ConstraintValidatorContext): Boolean {
         if (pageable == null) return true
+        if (!pageable.isPaged) return true
 
         var valid = true
         context.disableDefaultConstraintViolation()

samples/server/petstore/kotlin-springboot-sort-validation/src/test/kotlin/org/openapitools/api/PetApiValidationTest.kt

@@ -92,6 +92,14 @@ class PetApiValidationTest {
         }.andExpect { status { isBadRequest() } }
     }
 
+    @Test
+    fun `ValidPageable - unpaged Pageable is allowed (no params, no PageableDefault)`() {
+        // When no pagination parameters are supplied and no @PageableDefault is configured,
+        // Spring resolves Pageable.unpaged(). The validator must not throw and must return valid.
+        mockMvc.get("${PetApi.BASE_PATH}${PetApi.PATH_FIND_PETS_WITH_SIZE_CONSTRAINT}")
+            .andExpect { status { isOk() } }
+    }
+
     // ── @ValidPageable — size and page constraints combined ───────────────────
     // Endpoint: GET /pet/findWithPageAndSizeConstraint  maxSize = 50, maxPage = 999
 

samples/server/petstore/springboot-sort-validation/src/main/java/org/openapitools/configuration/ValidPageable.java

@@ -66,6 +66,10 @@ public boolean isValid(Pageable pageable, ConstraintValidatorContext context) {
                 return true;
             }
 
+            if (!pageable.isPaged()) {
+                return true;
+            }
+
             boolean valid = true;
             context.disableDefaultConstraintViolation();
 

samples/server/petstore/springboot-sort-validation/src/test/java/org/openapitools/api/PetApiValidationTest.java

@@ -96,6 +96,14 @@ void validPageable_sizeExceedsMaximumReturns400() throws Exception {
                 .andExpect(status().isBadRequest());
     }
 
+    @Test
+    void validPageable_unpagedPageableIsAllowed() throws Exception {
+        // When no pagination parameters are supplied and no @PageableDefault is configured,
+        // Spring resolves Pageable.unpaged(). The validator must not throw and must return valid.
+        mockMvc.perform(get(PetApi.PATH_FIND_PETS_WITH_SIZE_CONSTRAINT))
+                .andExpect(status().isOk());
+    }
+
     // ── @ValidPageable — size and page constraints combined ───────────────────
     // Endpoint: GET /pet/findWithPageAndSizeConstraint  maxSize = 50, maxPage = 999