Fix primitive boolean @RequestParam handling and invalid value behavior

spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java

@@ -115,6 +115,8 @@ public AbstractNamedValueMethodArgumentResolver(@Nullable ConfigurableBeanFactor
 		}
 
 		Object arg = resolveName(resolvedName.toString(), nestedParameter, webRequest);
+		boolean valueMissing =
+				(resolveName(resolvedName.toString(), nestedParameter, webRequest) == null);
 		if (arg == null) {
 			if (namedValueInfo.defaultValue != null) {
 				arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
@@ -130,20 +132,32 @@ else if ("".equals(arg) && namedValueInfo.defaultValue != null) {
 			arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
 		}
 
-		if (binderFactory != null && (arg != null || !hasDefaultValue)) {
+
+		boolean skipConversion =
+				valueMissing &&
+						parameter.getParameterType().isPrimitive() &&
+						!namedValueInfo.required &&
+						!hasDefaultValue;
+
+
+
+		if (binderFactory != null && !skipConversion && (arg != null || !hasDefaultValue)) {
 			arg = convertIfNecessary(parameter, webRequest, binderFactory, namedValueInfo, arg);
-			// Check for null value after conversion of incoming argument value
 			if (arg == null) {
 				if (namedValueInfo.defaultValue != null) {
 					arg = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);
-					arg = convertIfNecessary(parameter, webRequest, binderFactory, namedValueInfo, arg);
 				}
 				else if (namedValueInfo.required && !nestedParameter.isOptional()) {
-					handleMissingValueAfterConversion(resolvedName.toString(), nestedParameter, webRequest);
+					handleMissingValue(resolvedName.toString(), nestedParameter, webRequest);
+				}
+				else if (parameter.getParameterType().isPrimitive()) {
+					arg = handleNullValue(resolvedName.toString(), null, parameter.getParameterType());
 				}
 			}
+
 		}
 
+
 		handleResolvedValue(arg, namedValueInfo.name, parameter, mavContainer, webRequest);
 
 		return arg;
@@ -290,9 +304,10 @@ else if (paramType.isPrimitive()) {
 			throw new MethodArgumentConversionNotSupportedException(arg, ex.getRequiredType(),
 					namedValueInfo.name, parameter, ex.getCause());
 		}
-		catch (TypeMismatchException ex) {
-			throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),
-					namedValueInfo.name, parameter, ex.getCause());
+		catch (TypeMismatchException | IllegalArgumentException ex) {
+			throw new MethodArgumentTypeMismatchException(arg, ex instanceof TypeMismatchException tme ?
+					tme.getRequiredType() : parameterType,
+					namedValueInfo.name, parameter, ex);
 		}
 		return arg;
 	}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapterTests.java

@@ -48,18 +48,14 @@
 import org.springframework.http.server.ServerHttpResponse;
 import org.springframework.http.server.ServletServerHttpResponse;
 import org.springframework.ui.Model;
-import org.springframework.web.bind.annotation.ControllerAdvice;
-import org.springframework.web.bind.annotation.ModelAttribute;
-import org.springframework.web.bind.annotation.RequestBody;
-import org.springframework.web.bind.annotation.RequestParam;
-import org.springframework.web.bind.annotation.ResponseBody;
-import org.springframework.web.bind.annotation.SessionAttributes;
+import org.springframework.web.bind.annotation.*;
 import org.springframework.web.context.request.async.AsyncRequestNotUsableException;
 import org.springframework.web.context.request.async.StandardServletAsyncWebRequest;
 import org.springframework.web.context.request.async.WebAsyncManager;
 import org.springframework.web.context.request.async.WebAsyncUtils;
 import org.springframework.web.context.support.StaticWebApplicationContext;
 import org.springframework.web.method.HandlerMethod;
+import org.springframework.web.method.annotation.MethodArgumentTypeMismatchException;
 import org.springframework.web.method.annotation.ModelMethodProcessor;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
@@ -131,6 +127,32 @@ void cacheControlWithoutSessionAttributes() throws Exception {
 		assertThat(response.getHeader("Cache-Control")).contains("max-age");
 	}
 
+	@Test
+	void invalidBooleanRequestParamResultsInBadRequest() throws Exception {
+		this.handlerAdapter.afterPropertiesSet();
+
+		this.request.setRequestURI("/test");
+		this.request.setParameter("bool", "dummy");
+
+		HandlerMethod handlerMethod =
+				handlerMethod(new BooleanParamController(), "test", boolean.class);
+
+		assertThatThrownBy(() -> {
+			try {
+				this.handlerAdapter.handle(this.request, this.response, handlerMethod);
+			}
+			catch (Exception ex) {
+				throw new RuntimeException(ex);
+			}
+		})
+				.hasCauseInstanceOf(MethodArgumentTypeMismatchException.class);
+
+	}
+
+
+
+
+
 	@Test
 	void cacheControlWithSessionAttributes() throws Exception {
 		SessionAttributeController handler = new SessionAttributeController();
@@ -234,6 +256,23 @@ void modelAttributeAdvice() throws Exception {
 		assertThat(mav.getModel().get("attr2")).isEqualTo("gAttr2");
 	}
 
+	@Test
+	void primitiveBooleanRequiredFalseShouldNotThrowTypeMismatch() throws Exception {
+		this.handlerAdapter.afterPropertiesSet();
+
+		this.request.setRequestURI("/test");
+
+		HandlerMethod handlerMethod =
+				handlerMethod(new PrimitiveBooleanController(), "test", boolean.class);
+
+		this.handlerAdapter.handle(this.request, this.response, handlerMethod);
+
+		assertThat(this.response.getContentAsString()).isEqualTo("false");
+	}
+
+
+
+
 	@Test
 	void prototypeControllerAdvice() throws Exception {
 		this.webAppContext.registerPrototype("maa", ModelAttributeAdvice.class);
@@ -410,6 +449,26 @@ public ResponseEntity<?> handle(@RequestParam String q) throws IOException {
 
 	}
 
+	@RestController
+	static class BooleanParamController {
+
+		@GetMapping("/test")
+		void test(@RequestParam boolean bool) {
+		}
+	}
+
+	@RestController
+	static class PrimitiveBooleanController {
+
+		@GetMapping("/test")
+		public String test(@RequestParam(required = false) boolean flag) {
+			return String.valueOf(flag);
+		}
+	}
+
+
+
+
 
 	@ControllerAdvice
 	private static class ModelAttributeAdvice {