org.springframework.http.ReadOnlyHttpHeaders 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.http;
import java.util.AbstractMap.SimpleImmutableEntry;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import org.springframework.lang.Nullable;
import org.springframework.util.MultiValueMap;
/**
* {@code HttpHeaders} object that can only be read, not written to.
*
* @author Brian Clozel
* @author Sam Brannen
* @since 5.1.1
*/
class ReadOnlyHttpHeaders extends HttpHeaders {
private static final long serialVersionUID = -8578554704772377436L;
@Nullable
private MediaType cachedContentType;
@Nullable
@SuppressWarnings("serial")
private List cachedAccept;
ReadOnlyHttpHeaders(MultiValueMap headers) {
super(headers);
}
@Override
public MediaType getContentType() {
if (this.cachedContentType != null) {
return this.cachedContentType;
}
else {
MediaType contentType = super.getContentType();
this.cachedContentType = contentType;
return contentType;
}
}
@Override
public List getAccept() {
if (this.cachedAccept != null) {
return this.cachedAccept;
}
else {
List accept = super.getAccept();
this.cachedAccept = accept;
return accept;
}
}
@Override
public void clearContentHeaders() {
// No-op.
}
@Override
public List get(Object key) {
List values = this.headers.get(key);
return (values != null ? Collections.unmodifiableList(values) : null);
}
@Override
public void add(String headerName, @Nullable String headerValue) {
throw new UnsupportedOperationException();
}
@Override
public void addAll(String key, List values) {
throw new UnsupportedOperationException();
}
@Override
public void addAll(MultiValueMap values) {
throw new UnsupportedOperationException();
}
@Override
public void set(String headerName, @Nullable String headerValue) {
throw new UnsupportedOperationException();
}
@Override
public void setAll(Map values) {
throw new UnsupportedOperationException();
}
@Override
public Map toSingleValueMap() {
return Collections.unmodifiableMap(this.headers.toSingleValueMap());
}
@Override
public Set keySet() {
return Collections.unmodifiableSet(this.headers.keySet());
}
@Override
public List put(String key, List value) {
throw new UnsupportedOperationException();
}
@Override
public List remove(Object key) {
throw new UnsupportedOperationException();
}
@Override
public void putAll(Map> map) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
@Override
public Collection> values() {
return Collections.unmodifiableCollection(this.headers.values());
}
@Override
public Set>> entrySet() {
return this.headers.entrySet().stream().map(SimpleImmutableEntry::new)
.collect(Collectors.collectingAndThen(
Collectors.toCollection(LinkedHashSet::new), // Retain original ordering of entries
Collections::unmodifiableSet));
}
}