org.springframework.web.method.HandlerMethod Maven / Gradle / Ivy
/*
* 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.web.method;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.List;
import java.util.StringJoiner;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.MessageSource;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.core.MethodParameter;
import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.core.annotation.AnnotatedMethod;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.MergedAnnotation;
import org.springframework.core.annotation.MergedAnnotationPredicates;
import org.springframework.core.annotation.MergedAnnotations;
import org.springframework.http.HttpStatusCode;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.ResponseStatus;
/**
* Encapsulates information about a handler method consisting of a
* {@linkplain #getMethod() method} and a {@linkplain #getBean() bean}.
* Provides convenient access to method parameters, the method return value,
* method annotations, etc.
*
* The class may be created with a bean instance or with a bean name
* (e.g. lazy-init bean, prototype bean). Use {@link #createWithResolvedBean()}
* to obtain a {@code HandlerMethod} instance with a bean instance resolved
* through the associated {@link BeanFactory}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @author Sam Brannen
* @since 3.1
*/
public class HandlerMethod extends AnnotatedMethod {
/** Logger that is available to subclasses. */
protected static final Log logger = LogFactory.getLog(HandlerMethod.class);
private final Object bean;
@Nullable
private final BeanFactory beanFactory;
@Nullable
private final MessageSource messageSource;
private final Class beanType;
private final boolean validateArguments;
private final boolean validateReturnValue;
@Nullable
private HttpStatusCode responseStatus;
@Nullable
private String responseStatusReason;
@Nullable
private HandlerMethod resolvedFromHandlerMethod;
private final String description;
/**
* Create an instance from a bean instance and a method.
*/
public HandlerMethod(Object bean, Method method) {
this(bean, method, null);
}
/**
* Variant of {@link #HandlerMethod(Object, Method)} that
* also accepts a {@link MessageSource} for use from subclasses.
* @since 5.3.10
*/
protected HandlerMethod(Object bean, Method method, @Nullable MessageSource messageSource) {
super(method);
this.bean = bean;
this.beanFactory = null;
this.messageSource = messageSource;
this.beanType = ClassUtils.getUserClass(bean);
this.validateArguments = MethodValidationInitializer.checkArguments(this.beanType, getMethodParameters());
this.validateReturnValue = MethodValidationInitializer.checkReturnValue(this.beanType, getBridgedMethod());
evaluateResponseStatus();
this.description = initDescription(this.beanType, method);
}
/**
* Create an instance from a bean instance, method name, and parameter types.
* @throws NoSuchMethodException when the method cannot be found
*/
public HandlerMethod(Object bean, String methodName, Class... parameterTypes) throws NoSuchMethodException {
super(bean.getClass().getMethod(methodName, parameterTypes));
this.bean = bean;
this.beanFactory = null;
this.messageSource = null;
this.beanType = ClassUtils.getUserClass(bean);
this.validateArguments = MethodValidationInitializer.checkArguments(this.beanType, getMethodParameters());
this.validateReturnValue = MethodValidationInitializer.checkReturnValue(this.beanType, getBridgedMethod());
evaluateResponseStatus();
this.description = initDescription(this.beanType, getMethod());
}
/**
* Create an instance from a bean name, a method, and a {@code BeanFactory}.
* The method {@link #createWithResolvedBean()} may be used later to
* re-create the {@code HandlerMethod} with an initialized bean.
*/
public HandlerMethod(String beanName, BeanFactory beanFactory, Method method) {
this(beanName, beanFactory, null, method);
}
/**
* Variant of {@link #HandlerMethod(String, BeanFactory, Method)} that
* also accepts a {@link MessageSource}.
*/
public HandlerMethod(
String beanName, BeanFactory beanFactory,
@Nullable MessageSource messageSource, Method method) {
super(method);
Assert.hasText(beanName, "Bean name is required");
Assert.notNull(beanFactory, "BeanFactory is required");
this.bean = beanName;
this.beanFactory = beanFactory;
this.messageSource = messageSource;
Class beanType = beanFactory.getType(beanName);
if (beanType == null) {
throw new IllegalStateException("Cannot resolve bean type for bean with name '" + beanName + "'");
}
this.beanType = ClassUtils.getUserClass(beanType);
this.validateArguments = MethodValidationInitializer.checkArguments(this.beanType, getMethodParameters());
this.validateReturnValue = MethodValidationInitializer.checkReturnValue(this.beanType, getBridgedMethod());
evaluateResponseStatus();
this.description = initDescription(this.beanType, method);
}
/**
* Copy constructor for use in subclasses.
*/
protected HandlerMethod(HandlerMethod handlerMethod) {
super(handlerMethod);
this.bean = handlerMethod.bean;
this.beanFactory = handlerMethod.beanFactory;
this.messageSource = handlerMethod.messageSource;
this.beanType = handlerMethod.beanType;
this.validateArguments = handlerMethod.validateArguments;
this.validateReturnValue = handlerMethod.validateReturnValue;
this.responseStatus = handlerMethod.responseStatus;
this.responseStatusReason = handlerMethod.responseStatusReason;
this.description = handlerMethod.description;
this.resolvedFromHandlerMethod = handlerMethod.resolvedFromHandlerMethod;
}
/**
* Re-create HandlerMethod with the resolved handler.
*/
private HandlerMethod(HandlerMethod handlerMethod, Object handler) {
super(handlerMethod);
Assert.notNull(handler, "Handler object is required");
this.bean = handler;
this.beanFactory = handlerMethod.beanFactory;
this.messageSource = handlerMethod.messageSource;
this.beanType = handlerMethod.beanType;
this.validateArguments = handlerMethod.validateArguments;
this.validateReturnValue = handlerMethod.validateReturnValue;
this.responseStatus = handlerMethod.responseStatus;
this.responseStatusReason = handlerMethod.responseStatusReason;
this.resolvedFromHandlerMethod = handlerMethod;
this.description = handlerMethod.description;
}
private void evaluateResponseStatus() {
ResponseStatus annotation = getMethodAnnotation(ResponseStatus.class);
if (annotation == null) {
annotation = AnnotatedElementUtils.findMergedAnnotation(getBeanType(), ResponseStatus.class);
}
if (annotation != null) {
String reason = annotation.reason();
String resolvedReason = (StringUtils.hasText(reason) && this.messageSource != null ?
this.messageSource.getMessage(reason, null, reason, LocaleContextHolder.getLocale()) :
reason);
this.responseStatus = annotation.code();
this.responseStatusReason = resolvedReason;
if (StringUtils.hasText(this.responseStatusReason) && getMethod().getReturnType() != void.class) {
logger.warn("Return value of [" + getMethod() + "] will be ignored since @ResponseStatus 'reason' attribute is set.");
}
}
}
private static String initDescription(Class beanType, Method method) {
StringJoiner joiner = new StringJoiner(", ", "(", ")");
for (Class paramType : method.getParameterTypes()) {
joiner.add(paramType.getSimpleName());
}
return beanType.getName() + "#" + method.getName() + joiner;
}
/**
* Return the bean for this handler method.
*/
public Object getBean() {
return this.bean;
}
/**
* This method returns the type of the handler for this handler method.
*
Note that if the bean type is a CGLIB-generated class, the original
* user-defined class is returned.
*/
public Class getBeanType() {
return this.beanType;
}
@Override
protected Class getContainingClass() {
return this.beanType;
}
/**
* Whether the method arguments are a candidate for method validation, which
* is the case when there are parameter {@code jakarta.validation.Constraint}
* annotations.
*
The presence of {@code jakarta.validation.Valid} by itself does not
* trigger method validation since such parameters are already validated at
* the level of argument resolvers.
*
Note: if the class is annotated with {@link Validated},
* this method returns false, deferring to method validation via AOP proxy.
* @since 6.1
*/
public boolean shouldValidateArguments() {
return this.validateArguments;
}
/**
* Whether the method return value is a candidate for method validation, which
* is the case when there are method {@code jakarta.validation.Constraint}
* or {@code jakarta.validation.Valid} annotations.
*
Note: if the class is annotated with {@link Validated},
* this method returns false, deferring to method validation via AOP proxy.
* @since 6.1
*/
public boolean shouldValidateReturnValue() {
return this.validateReturnValue;
}
/**
* Return the specified response status, if any.
* @since 4.3.8
* @see ResponseStatus#code()
*/
@Nullable
protected HttpStatusCode getResponseStatus() {
return this.responseStatus;
}
/**
* Return the associated response status reason, if any.
* @since 4.3.8
* @see ResponseStatus#reason()
*/
@Nullable
protected String getResponseStatusReason() {
return this.responseStatusReason;
}
/**
* Return the HandlerMethod from which this HandlerMethod instance was
* resolved via {@link #createWithResolvedBean()}.
*/
@Nullable
public HandlerMethod getResolvedFromHandlerMethod() {
return this.resolvedFromHandlerMethod;
}
/**
* If the provided instance contains a bean name rather than an object instance,
* the bean name is resolved before a {@link HandlerMethod} is created and returned.
*/
public HandlerMethod createWithResolvedBean() {
Object handler = this.bean;
if (this.bean instanceof String beanName) {
Assert.state(this.beanFactory != null, "Cannot resolve bean name without BeanFactory");
handler = this.beanFactory.getBean(beanName);
}
return new HandlerMethod(this, handler);
}
/**
* Return a short representation of this handler method for log message purposes.
* @since 4.3
*/
public String getShortLogMessage() {
return getBeanType().getName() + "#" + getMethod().getName() +
"[" + getMethod().getParameterCount() + " args]";
}
@Override
public boolean equals(@Nullable Object other) {
return (this == other || (super.equals(other) && this.bean.equals(((HandlerMethod) other).bean)));
}
@Override
public int hashCode() {
return (this.bean.hashCode() * 31 + super.hashCode());
}
@Override
public String toString() {
return this.description;
}
// Support methods for use in subclass variants
/**
* Assert that the target bean class is an instance of the class where the given
* method is declared. In some cases the actual controller instance at request-
* processing time may be a JDK dynamic proxy (lazy initialization, prototype
* beans, and others). {@code @Controller}'s that require proxying should prefer
* class-based proxy mechanisms.
*/
protected void assertTargetBean(Method method, Object targetBean, Object[] args) {
Class methodDeclaringClass = method.getDeclaringClass();
Class targetBeanClass = targetBean.getClass();
if (!methodDeclaringClass.isAssignableFrom(targetBeanClass)) {
String text = "The mapped handler method class '" + methodDeclaringClass.getName() +
"' is not an instance of the actual controller bean class '" +
targetBeanClass.getName() + "'. If the controller requires proxying " +
"(e.g. due to @Transactional), please use class-based proxying.";
throw new IllegalStateException(formatInvokeError(text, args));
}
}
protected String formatInvokeError(String text, Object[] args) {
String formattedArgs = IntStream.range(0, args.length)
.mapToObj(i -> (args[i] != null ?
"[" + i + "] [type=" + args[i].getClass().getName() + "] [value=" + args[i] + "]" :
"[" + i + "] [null]"))
.collect(Collectors.joining(",\n", " ", " "));
return text + "\n" +
"Controller [" + getBeanType().getName() + "]\n" +
"Method [" + getBridgedMethod().toGenericString() + "] " +
"with argument values:\n" + formattedArgs;
}
/**
* Checks for the presence of {@code @Constraint} and {@code @Valid}
* annotations on the method and method parameters.
*/
private static class MethodValidationInitializer {
private static final Predicate> CONSTRAINT_PREDICATE =
MergedAnnotationPredicates.typeIn("jakarta.validation.Constraint");
private static final Predicate> VALID_PREDICATE =
MergedAnnotationPredicates.typeIn("jakarta.validation.Valid");
public static boolean checkArguments(Class beanType, MethodParameter[] parameters) {
if (AnnotationUtils.findAnnotation(beanType, Validated.class) == null) {
for (MethodParameter parameter : parameters) {
MergedAnnotations merged = MergedAnnotations.from(parameter.getParameterAnnotations());
if (merged.stream().anyMatch(CONSTRAINT_PREDICATE)) {
return true;
}
else {
Class type = parameter.getParameterType();
if (merged.stream().anyMatch(VALID_PREDICATE) && List.class.isAssignableFrom(type)) {
return true;
}
}
}
}
return false;
}
public static boolean checkReturnValue(Class beanType, Method method) {
if (AnnotationUtils.findAnnotation(beanType, Validated.class) == null) {
MergedAnnotations merged = MergedAnnotations.from(method, MergedAnnotations.SearchStrategy.TYPE_HIERARCHY);
return merged.stream().anyMatch(CONSTRAINT_PREDICATE.or(VALID_PREDICATE));
}
return false;
}
}
}