org.springframework.web.servlet.mvc.condition.RequestMethodsRequestCondition Maven / Gradle / Ivy
/*
* Copyright 2002-2020 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.servlet.mvc.condition;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import javax.servlet.DispatcherType;
import javax.servlet.http.HttpServletRequest;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.lang.Nullable;
import org.springframework.util.ObjectUtils;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.cors.CorsUtils;
/**
* A logical disjunction (' || ') request condition that matches a request
* against a set of {@link RequestMethod RequestMethods}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 3.1
*/
public final class RequestMethodsRequestCondition extends AbstractRequestCondition {
/** Per HTTP method cache to return ready instances from getMatchingCondition. */
private static final Map requestMethodConditionCache;
static {
requestMethodConditionCache = new HashMap<>(RequestMethod.values().length);
for (RequestMethod method : RequestMethod.values()) {
requestMethodConditionCache.put(method.name(), new RequestMethodsRequestCondition(method));
}
}
private final Set methods;
/**
* Create a new instance with the given request methods.
* @param requestMethods 0 or more HTTP request methods;
* if, 0 the condition will match to every request
*/
public RequestMethodsRequestCondition(RequestMethod... requestMethods) {
this.methods = (ObjectUtils.isEmpty(requestMethods) ?
Collections.emptySet() : new LinkedHashSet<>(Arrays.asList(requestMethods)));
}
/**
* Private constructor for internal use when combining conditions.
*/
private RequestMethodsRequestCondition(Set methods) {
this.methods = methods;
}
/**
* Returns all {@link RequestMethod RequestMethods} contained in this condition.
*/
public Set getMethods() {
return this.methods;
}
@Override
protected Collection getContent() {
return this.methods;
}
@Override
protected String getToStringInfix() {
return " || ";
}
/**
* Returns a new instance with a union of the HTTP request methods
* from "this" and the "other" instance.
*/
@Override
public RequestMethodsRequestCondition combine(RequestMethodsRequestCondition other) {
if (isEmpty() && other.isEmpty()) {
return this;
}
else if (other.isEmpty()) {
return this;
}
else if (isEmpty()) {
return other;
}
Set set = new LinkedHashSet<>(this.methods);
set.addAll(other.methods);
return new RequestMethodsRequestCondition(set);
}
/**
* Check if any of the HTTP request methods match the given request and
* return an instance that contains the matching HTTP request method only.
* @param request the current request
* @return the same instance if the condition is empty (unless the request
* method is HTTP OPTIONS), a new condition with the matched request method,
* or {@code null} if there is no match or the condition is empty and the
* request method is OPTIONS.
*/
@Override
@Nullable
public RequestMethodsRequestCondition getMatchingCondition(HttpServletRequest request) {
if (CorsUtils.isPreFlightRequest(request)) {
return matchPreFlight(request);
}
if (getMethods().isEmpty()) {
if (RequestMethod.OPTIONS.name().equals(request.getMethod()) &&
!DispatcherType.ERROR.equals(request.getDispatcherType())) {
return null; // We handle OPTIONS transparently, so don't match if no explicit declarations
}
return this;
}
return matchRequestMethod(request.getMethod());
}
/**
* On a pre-flight request match to the would-be, actual request.
* Hence empty conditions is a match, otherwise try to match to the HTTP
* method in the "Access-Control-Request-Method" header.
*/
@Nullable
private RequestMethodsRequestCondition matchPreFlight(HttpServletRequest request) {
if (getMethods().isEmpty()) {
return this;
}
String expectedMethod = request.getHeader(HttpHeaders.ACCESS_CONTROL_REQUEST_METHOD);
return matchRequestMethod(expectedMethod);
}
@Nullable
private RequestMethodsRequestCondition matchRequestMethod(String httpMethodValue) {
RequestMethod requestMethod;
try {
requestMethod = RequestMethod.valueOf(httpMethodValue);
if (getMethods().contains(requestMethod)) {
return requestMethodConditionCache.get(httpMethodValue);
}
if (requestMethod.equals(RequestMethod.HEAD) && getMethods().contains(RequestMethod.GET)) {
return requestMethodConditionCache.get(HttpMethod.GET.name());
}
}
catch (IllegalArgumentException ex) {
// Custom request method
}
return null;
}
/**
* Returns:
*
* - 0 if the two conditions contain the same number of HTTP request methods
*
- Less than 0 if "this" instance has an HTTP request method but "other" doesn't
*
- Greater than 0 "other" has an HTTP request method but "this" doesn't
*
* It is assumed that both instances have been obtained via
* {@link #getMatchingCondition(HttpServletRequest)} and therefore each instance
* contains the matching HTTP request method only or is otherwise empty.
*/
@Override
public int compareTo(RequestMethodsRequestCondition other, HttpServletRequest request) {
if (other.methods.size() != this.methods.size()) {
return other.methods.size() - this.methods.size();
}
else if (this.methods.size() == 1) {
if (this.methods.contains(RequestMethod.HEAD) && other.methods.contains(RequestMethod.GET)) {
return -1;
}
else if (this.methods.contains(RequestMethod.GET) && other.methods.contains(RequestMethod.HEAD)) {
return 1;
}
}
return 0;
}
}