org.springframework.web.server.handler.DefaultWebFilterChain Maven / Gradle / Ivy
/*
* Copyright 2002-2019 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.server.handler;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.ListIterator;
import reactor.core.publisher.Mono;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import org.springframework.web.server.WebHandler;
/**
* Default implementation of {@link WebFilterChain}.
*
* Each instance of this class represents one link in the chain. The public
* constructor {@link #DefaultWebFilterChain(WebHandler, List)}
* initializes the full chain and represents its first link.
*
*
This class is immutable and thread-safe. It can be created once and
* re-used to handle request concurrently.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public class DefaultWebFilterChain implements WebFilterChain {
private final List allFilters;
private final WebHandler handler;
@Nullable
private final WebFilter currentFilter;
@Nullable
private final DefaultWebFilterChain chain;
/**
* Public constructor with the list of filters and the target handler to use.
* @param handler the target handler
* @param filters the filters ahead of the handler
* @since 5.1
*/
public DefaultWebFilterChain(WebHandler handler, List filters) {
Assert.notNull(handler, "WebHandler is required");
this.allFilters = Collections.unmodifiableList(filters);
this.handler = handler;
DefaultWebFilterChain chain = initChain(filters, handler);
this.currentFilter = chain.currentFilter;
this.chain = chain.chain;
}
private static DefaultWebFilterChain initChain(List filters, WebHandler handler) {
DefaultWebFilterChain chain = new DefaultWebFilterChain(filters, handler, null, null);
ListIterator iterator = filters.listIterator(filters.size());
while (iterator.hasPrevious()) {
chain = new DefaultWebFilterChain(filters, handler, iterator.previous(), chain);
}
return chain;
}
/**
* Private constructor to represent one link in the chain.
*/
private DefaultWebFilterChain(List allFilters, WebHandler handler,
@Nullable WebFilter currentFilter, @Nullable DefaultWebFilterChain chain) {
this.allFilters = allFilters;
this.currentFilter = currentFilter;
this.handler = handler;
this.chain = chain;
}
/**
* Public constructor with the list of filters and the target handler to use.
* @param handler the target handler
* @param filters the filters ahead of the handler
* @deprecated as of 5.1 this constructor is deprecated in favor of
* {@link #DefaultWebFilterChain(WebHandler, List)}.
*/
@Deprecated
public DefaultWebFilterChain(WebHandler handler, WebFilter... filters) {
this(handler, Arrays.asList(filters));
}
public List getFilters() {
return this.allFilters;
}
public WebHandler getHandler() {
return this.handler;
}
@Override
public Mono filter(ServerWebExchange exchange) {
return Mono.defer(() ->
this.currentFilter != null && this.chain != null ?
invokeFilter(this.currentFilter, this.chain, exchange) :
this.handler.handle(exchange));
}
private Mono invokeFilter(WebFilter current, DefaultWebFilterChain chain, ServerWebExchange exchange) {
String currentName = current.getClass().getName();
return current.filter(exchange, chain).checkpoint(currentName + " [DefaultWebFilterChain]");
}
}