Add MethodValidationResult

See gh-29825

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationAdapter.java

@@ -18,6 +18,7 @@
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
@@ -73,6 +74,8 @@ public class MethodValidationAdapter {
 
  private static final Comparator<ParameterValidationResult> RESULT_COMPARATOR = new ResultComparator();
 
+ private static final MethodValidationResult EMPTY_RESULT = new EmptyMethodValidationResult();
+
 
  private final Supplier<Validator> validator;
 
@@ -186,15 +189,19 @@ public static Class<?>[] determineValidationGroups(Object target, Method method)
  }
 
  /**
- * Validate the given method arguments and raise {@link ConstraintViolation}
- * in case of any errors.
+ * Validate the given method arguments and return the result of validation.
  * @param target the target Object
  * @param method the target method
  * @param arguments candidate arguments for a method invocation
  * @param groups groups for validation determined via
  * {@link #determineValidationGroups(Object, Method)}
+ * @return a result with {@link ConstraintViolation violations} and
+ * {@link ParameterValidationResult validationResults}, both possibly empty
+ * in case there are no violations
  */
- public void validateMethodArguments(Object target, Method method, Object[] arguments, Class<?>[] groups) {
+ public MethodValidationResult validateMethodArguments(
+ Object target, Method method, Object[] arguments, Class<?>[] groups) {
+
  ExecutableValidator execVal = this.validator.get().forExecutables();
  Set<ConstraintViolation<Object>> result;
  try {
@@ -207,28 +214,26 @@ public void validateMethodArguments(Object target, Method method, Object[] argum
  Method bridgedMethod = BridgeMethodResolver.findBridgedMethod(mostSpecificMethod);
  result = execVal.validateParameters(target, bridgedMethod, arguments, groups);
  }
- if (!result.isEmpty()) {
- throw createException(target, method, result, i -> arguments[i]);
- }
+ return (result.isEmpty() ? EMPTY_RESULT : createException(target, method, result, i -> arguments[i]));
  }
 
  /**
- * Validate the given return value and raise {@link ConstraintViolation}
- * in case of any errors.
+ * Validate the given return value and return the result of validation.
  * @param target the target Object
  * @param method the target method
  * @param returnValue value returned from invoking the target method
  * @param groups groups for validation determined via
  * {@link #determineValidationGroups(Object, Method)}
+ * @return a result with {@link ConstraintViolation violations} and
+ * {@link ParameterValidationResult validationResults}, both possibly empty
+ * in case there are no violations
  */
- public void validateMethodReturnValue(
+ public MethodValidationResult validateMethodReturnValue(
  Object target, Method method, @Nullable Object returnValue, Class<?>[] groups) {
 
  ExecutableValidator execVal = this.validator.get().forExecutables();
  Set<ConstraintViolation<Object>> result = execVal.validateReturnValue(target, method, returnValue, groups);
- if (!result.isEmpty()) {
- throw createException(target, method, result, i -> returnValue);
- }
+ return (result.isEmpty() ? EMPTY_RESULT : createException(target, method, result, i -> returnValue));
  }
 
  private MethodValidationException createException(
@@ -275,7 +280,7 @@ else if (node.getKind().equals(ElementKind.RETURN_VALUE)) {
  cascadedViolations.forEach((node, builder) -> validatonResultList.add(builder.build()));
  validatonResultList.sort(RESULT_COMPARATOR);
 
- return new MethodValidationException(target, method, validatonResultList, violations);
+ return new MethodValidationException(target, method, violations, validatonResultList);
  }
 
  /**
@@ -470,4 +475,36 @@ private <E> int compareKeys(ParameterErrors errors1, ParameterErrors errors2) {
  }
  }
 
+
+ /**
+ * {@link MethodValidationResult} to use when there are no violations.
+ */
+ private static final class EmptyMethodValidationResult implements MethodValidationResult {
+
+ @Override
+ public Set<ConstraintViolation<?>> getConstraintViolations() {
+ return Collections.emptySet();
+ }
+
+ @Override
+ public List<ParameterValidationResult> getAllValidationResults() {
+ return Collections.emptyList();
+ }
+
+ @Override
+ public List<ParameterValidationResult> getValueResults() {
+ return Collections.emptyList();
+ }
+
+ @Override
+ public List<ParameterErrors> getBeanResults() {
+ return Collections.emptyList();
+ }
+
+ @Override
+ public void throwIfViolationsPresent() {
+ }
+
+ }
+
 }

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationException.java

@@ -23,17 +23,15 @@
 import jakarta.validation.ConstraintViolation;
 import jakarta.validation.ConstraintViolationException;
 
+import org.springframework.util.Assert;
+
 /**
- * Extension of {@link ConstraintViolationException} that exposes an additional
- * list of {@link ParameterValidationResult} with violations adapted to
+ * Extension of {@link ConstraintViolationException} that implements
+ * {@link MethodValidationResult} exposing an additional list of
+ * {@link ParameterValidationResult} that represents violations adapted to
  * {@link org.springframework.context.MessageSourceResolvable} and grouped by
  * method parameter.
  *
- * <p>For {@link jakarta.validation.Valid @Valid}-annotated, Object method
- * parameters or return types with cascaded violations, the {@link ParameterErrors}
- * subclass of {@link ParameterValidationResult} implements
- * {@link org.springframework.validation.Errors} and exposes
- * {@link org.springframework.validation.FieldError field errors}.
  *
  * @author Rossen Stoyanchev
  * @since 6.1
@@ -42,7 +40,7 @@
  * @see MethodValidationAdapter
  */
 @SuppressWarnings("serial")
-public class MethodValidationException extends ConstraintViolationException {
+public class MethodValidationException extends ConstraintViolationException implements MethodValidationResult {
 
  private final Object target;
 
@@ -52,11 +50,11 @@ public class MethodValidationException extends ConstraintViolationException {
 
 
  public MethodValidationException(
- Object target, Method method,
- List<ParameterValidationResult> validationResults,
- Set<? extends ConstraintViolation<?>> violations) {
+ Object target, Method method, Set<? extends ConstraintViolation<?>> violations,
+ List<ParameterValidationResult> validationResults) {
 
  super(violations);
+ Assert.notEmpty(violations, "'violations' must not be empty");
  this.target = target;
  this.method = method;
  this.allValidationResults = validationResults;
@@ -77,42 +75,36 @@ public Method getMethod() {
  return this.method;
  }
 
- /**
- * Return all validation results. This includes method parameters with
-  * constraints declared on them, as well as
-  * {@link jakarta.validation.Valid @Valid} method parameters with
-  * cascaded constraints.
-  * @see #getValueResults()
- * @see #getBeanResults()
-  */
+ // re-declare parent class method for NonNull treatment of interface
+
+ @Override
+ public Set<ConstraintViolation<?>> getConstraintViolations() {
+  return super.getConstraintViolations();
+ }
+
+ @Override
  public List<ParameterValidationResult> getAllValidationResults() {
  return this.allValidationResults;
  }
 
- /**
- * Return only validation results for method parameters with constraints
- * declared directly on them. This excludes
- * {@link jakarta.validation.Valid @Valid} method parameters with cascaded
- * constraints.
- * @see #getAllValidationResults()
- */
+ @Override
  public List<ParameterValidationResult> getValueResults() {
  return this.allValidationResults.stream()
  .filter(result -> !(result instanceof ParameterErrors))
  .toList();
  }
 
- /**
- * Return only validation results for {@link jakarta.validation.Valid @Valid}
- * method parameters with cascaded constraints. This excludes method
- * parameters with constraints declared directly on them.
- * @see #getAllValidationResults()
- */
+ @Override
  public List<ParameterErrors> getBeanResults() {
  return this.allValidationResults.stream()
  .filter(result -> result instanceof ParameterErrors)
  .map(result -> (ParameterErrors) result)
  .toList();
  }
 
+ @Override
+ public void throwIfViolationsPresent() {
+ throw this;
+ }
+
 }

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationInterceptor.java

@@ -103,11 +103,15 @@ public Object invoke(MethodInvocation invocation) throws Throwable {
  Object target = getTarget(invocation);
  Method method = invocation.getMethod();
  Class<?>[] groups = determineValidationGroups(invocation);
- this.delegate.validateMethodArguments(target, method, invocation.getArguments(), groups);
+
+ this.delegate.validateMethodArguments(target, method, invocation.getArguments(), groups)
+ .throwIfViolationsPresent();
 
  Object returnValue = invocation.proceed();
 
- this.delegate.validateMethodReturnValue(target, method, returnValue, groups);
+ this.delegate.validateMethodReturnValue(target, method, returnValue, groups)
+ .throwIfViolationsPresent();
+
  return returnValue;
  }
 

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationResult.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation.beanvalidation;
+
+import java.util.List;
+import java.util.Set;
+
+import jakarta.validation.ConstraintViolation;
+
+/**
+ * Container for method validation results where underlying
+ * {@link ConstraintViolation violations} have been adapted to
+ * {@link ParameterValidationResult} each containing a list of
+ * {@link org.springframework.context.MessageSourceResolvable} grouped by method
+ * parameter.
+ *
+ * <p>For {@link jakarta.validation.Valid @Valid}-annotated, Object method
+ * parameters or return types with cascaded violations, the {@link ParameterErrors}
+ * subclass of {@link ParameterValidationResult} implements
+ * {@link org.springframework.validation.Errors} and exposes
+ * {@link org.springframework.validation.FieldError field errors}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 6.1
+ */
+public interface MethodValidationResult {
+
+ /**
+ * Returns the set of constraint violations reported during a validation.
+ * @return the {@code Set} of {@link ConstraintViolation}s, or an empty Set
+ */
+ Set<ConstraintViolation<?>> getConstraintViolations();
+
+ /**
+ * Return all validation results. This includes method parameters with
+ * constraints declared on them, as well as
+ * {@link jakarta.validation.Valid @Valid} method parameters with
+ * cascaded constraints.
+ * @see #getValueResults()
+ * @see #getBeanResults()
+ */
+ List<ParameterValidationResult> getAllValidationResults();
+
+ /**
+ * Return only validation results for method parameters with constraints
+ * declared directly on them. This excludes
+ * {@link jakarta.validation.Valid @Valid} method parameters with cascaded
+ * constraints.
+ * @see #getAllValidationResults()
+ */
+ List<ParameterValidationResult> getValueResults();
+
+ /**
+ * Return only validation results for {@link jakarta.validation.Valid @Valid}
+ * method parameters with cascaded constraints. This excludes method
+ * parameters with constraints declared directly on them.
+ * @see #getAllValidationResults()
+ */
+ List<ParameterErrors> getBeanResults();
+
+ /**
+ * Check if {@link #getConstraintViolations()} is empty, and if not, raise
+ * {@link MethodValidationException}.
+ * @throws MethodValidationException if the result contains any violations
+ */
+ void throwIfViolationsPresent();
+
+}

spring-context/src/test/java/org/springframework/validation/beanvalidation/MethodValidationAdapterTests.java

@@ -32,14 +32,15 @@
 import org.springframework.validation.FieldError;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Unit tests for {@link MethodValidationAdapter}.
  * @author Rossen Stoyanchev
  */
 public class MethodValidationAdapterTests {
 
+ private static final MethodValidationAdapter validationAdapter = new MethodValidationAdapter();
+
  private static final Person faustino1234 = new Person("Faustino1234");
 
  private static final Person cayetana6789 = new Person("Cayetana6789");
@@ -154,23 +155,17 @@ void validateListArgument() {
  }
 
  private void validateArguments(
- Object target, Method method, Object[] arguments, Consumer<MethodValidationException> assertions) {
-
- MethodValidationAdapter adapter = new MethodValidationAdapter();
+ Object target, Method method, Object[] arguments, Consumer<MethodValidationResult> assertions) {
 
- assertThatExceptionOfType(MethodValidationException.class)
- .isThrownBy(() -> adapter.validateMethodArguments(target, method, arguments, new Class<?>[0]))
- .satisfies(assertions);
+ assertions.accept(
+ validationAdapter.validateMethodArguments(target, method, arguments, new Class<?>[0]));
  }
 
  private void validateReturnValue(
- Object target, Method method, @Nullable Object returnValue, Consumer<MethodValidationException> assertions) {
-
- MethodValidationAdapter adapter = new MethodValidationAdapter();
+ Object target, Method method, @Nullable Object returnValue, Consumer<MethodValidationResult> assertions) {
 
- assertThatExceptionOfType(MethodValidationException.class)
- .isThrownBy(() -> adapter.validateMethodReturnValue(target, method, returnValue, new Class<?>[0]))
- .satisfies(assertions);
+ assertions.accept(
+ validationAdapter.validateMethodReturnValue(target, method, returnValue, new Class<?>[0]));
  }
 
  private static void assertBeanResult(
@@ -225,12 +220,6 @@ public void addPeople(@Valid List<Person> people) {
 
  @SuppressWarnings("unused")
  private record Person(@Size(min = 1, max = 10) String name) {
-
- @Override
- public String name() {
- return this.name;
- }
-
  }
 
 }