/*
* Copyright 2002-2010 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
*
* http://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.net.URI;
import java.nio.charset.Charset;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.TimeZone;
import org.springframework.util.Assert;
import org.springframework.util.LinkedCaseInsensitiveMap;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;
/**
* Represents HTTP request and response headers, mapping string header names to list of string values.
*
* <p>In addition to the normal methods defined by {@link Map}, this class offers the following convenience methods:
* <ul>
* <li>{@link #getFirst(String)} returns the first value associated with a given header name</li>
* <li>{@link #add(String, String)} adds a header value to the list of values for a header name</li>
* <li>{@link #set(String, String)} sets the header value to a single string value</li>
* </ul>
*
* <p>Inspired by {@link com.sun.net.httpserver.Headers}.
*
* @author Arjen Poutsma
* @since 3.0
*/
public class HttpHeaders implements MultiValueMap<String, String> {
private static final String ACCEPT = "Accept";
private static final String ACCEPT_CHARSET = "Accept-Charset";
private static final String ALLOW = "Allow";
private static final String CACHE_CONTROL = "Cache-Control";
private static final String CONTENT_DISPOSITION = "Content-Disposition";
private static final String CONTENT_LENGTH = "Content-Length";
private static final String CONTENT_TYPE = "Content-Type";
private static final String DATE = "Date";
private static final String ETAG = "ETag";
private static final String EXPIRES = "Expires";
private static final String IF_MODIFIED_SINCE = "If-Modified-Since";
private static final String IF_NONE_MATCH = "If-None-Match";
private static final String LAST_MODIFIED = "Last-Modified";
private static final String LOCATION = "Location";
private static final String PRAGMA = "Pragma";
private static final String[] DATE_FORMATS = new String[] {
"EEE, dd MMM yyyy HH:mm:ss zzz",
"EEE, dd-MMM-yy HH:mm:ss zzz",
"EEE MMM dd HH:mm:ss yyyy"
};
private static TimeZone GMT = TimeZone.getTimeZone("GMT");
private final Map<String, List<String>> headers;
/**
* Private constructor that can create read-only {@code HttpHeader} instances.
*/
private HttpHeaders(Map<String, List<String>> headers, boolean readOnly) {
Assert.notNull(headers, "'headers' must not be null");
if (readOnly) {
Map<String, List<String>> map =
new LinkedCaseInsensitiveMap<List<String>>(headers.size(), Locale.ENGLISH);
for (Entry<String, List<String>> entry : headers.entrySet()) {
List<String> values = Collections.unmodifiableList(entry.getValue());
map.put(entry.getKey(), values);
}
this.headers = Collections.unmodifiableMap(map);
}
else {
this.headers = headers;
}
}
/**
* Constructs a new, empty instance of the {@code HttpHeaders} object.
*/
public HttpHeaders() {
this(new LinkedCaseInsensitiveMap<List<String>>(8, Locale.ENGLISH), false);
}
/**
* Returns {@code HttpHeaders} object that can only be read, not written to.
*/
public static HttpHeaders readOnlyHttpHeaders(HttpHeaders headers) {
return new HttpHeaders(headers, true);
}
/**
* Set the list of acceptable {@linkplain MediaType media types}, as specified by the {@code Accept} header.
* @param acceptableMediaTypes the acceptable media types
*/
public void setAccept(List<MediaType> acceptableMediaTypes) {
set(ACCEPT, MediaType.toString(acceptableMediaTypes));
}
/**
* Return the list of acceptable {@linkplain MediaType media types}, as specified by the {@code Accept} header.
* <p>Returns an empty list when the acceptable media types are unspecified.
* @return the acceptable media types
*/
public List<MediaType> getAccept() {
String value = getFirst(ACCEPT);
return (value != null ? MediaType.parseMediaTypes(value) : Collections.<MediaType>emptyList());
}
/**
* Set the list of acceptable {@linkplain Charset charsets}, as specified by the {@code Accept-Charset} header.
* @param acceptableCharsets the acceptable charsets
*/
public void setAcceptCharset(List<Charset> acceptableCharsets) {
StringBuilder builder = new StringBuilder();
for (Iterator<Charset> iterator = acceptableCharsets.iterator(); iterator.hasNext();) {
Charset charset = iterator.next();
builder.append(charset.name().toLowerCase(Locale.ENGLISH));
if (iterator.hasNext()) {
builder.append(", ");
}
}
set(ACCEPT_CHARSET, builder.toString());
}
/**
* Return the list of acceptable {@linkplain Charset charsets}, as specified by the {@code Accept-Charset}
* header.
* @return the acceptable charsets
*/
public List<Charset> getAcceptCharset() {
List<Charset> result = new ArrayList<Charset>();
String value = getFirst(ACCEPT_CHARSET);
if (value != null) {
String[] tokens = value.split(",\\s*");
for (String token : tokens) {
int paramIdx = token.indexOf(';');
if (paramIdx == -1) {
result.add(Charset.forName(token));
}
else {
result.add(Charset.forName(token.substring(0, paramIdx)));
}
}
}
return result;
}
/**
* Set the set of allowed {@link HttpMethod HTTP methods}, as specified by the {@code Allow} header.
* @param allowedMethods the allowed methods
*/
public void setAllow(Set<HttpMethod> allowedMethods) {
set(ALLOW, StringUtils.collectionToCommaDelimitedString(allowedMethods));
}
/**
* Return the set of allowed {@link HttpMethod HTTP methods}, as specified by the {@code Allow} header.
* <p>Returns an empty set when the allowed methods are unspecified.
* @return the allowed methods
*/
public Set<HttpMethod> getAllow() {
String value = getFirst(ALLOW);
if (value != null) {
List<HttpMethod> allowedMethod = new ArrayList<HttpMethod>(5);
String[] tokens = value.split(",\\s*");
for (String token : tokens) {
allowedMethod.add(HttpMethod.valueOf(token));
}
return EnumSet.copyOf(allowedMethod);
}
else {
return EnumSet.noneOf(HttpMethod.class);
}
}
/**
* Sets the (new) value of the {@code Cache-Control} header.
* @param cacheControl the value of the header
*/
public void setCacheControl(String cacheControl) {
set(CACHE_CONTROL, cacheControl);
}
/**
* Returns the value of the {@code Cache-Control} header.
* @return the value of the header
*/
public String getCacheControl() {
return getFirst(CACHE_CONTROL);
}
/**
* Sets the (new) value of the {@code Content-Disposition} header for {@code form-data}.
* @param name the control name
* @param filename the filename, may be {@code null}
*/
public void setContentDispositionFormData(String name, String filename) {
Assert.notNull(name, "'name' must not be null");
StringBuilder builder = new StringBuilder("form-data; name=\"");
builder.append(name).append('\"');
if (filename != null) {
builder.append("; filename=\"");
builder.append(filename).append('\"');
}
set(CONTENT_DISPOSITION, builder.toString());
}
/**
* Set the length of the body in bytes, as specified by the {@code Content-Length} header.
* @param contentLength the content length
*/
public void setContentLength(long contentLength) {
set(CONTENT_LENGTH, Long.toString(contentLength));
}
/**
* Return the length of the body in bytes, as specified by the {@code Content-Length} header.
* <p>Returns -1 when the content-length is unknown.
* @return the content length
*/
public long getContentLength() {
String value = getFirst(CONTENT_LENGTH);
return (value != null ? Long.parseLong(value) : -1);
}
/**
* Set the {@linkplain MediaType media type} of the body, as specified by the {@code Content-Type} header.
* @param mediaType the media type
*/
public void setContentType(MediaType mediaType) {
Assert.isTrue(!mediaType.isWildcardType(), "'Content-Type' cannot contain wildcard type '*'");
Assert.isTrue(!mediaType.isWildcardSubtype(), "'Content-Type' cannot contain wildcard subtype '*'");
set(CONTENT_TYPE, mediaType.toString());
}
/**
* Return the {@linkplain MediaType media type} of the body, as specified by the {@code Content-Type} header.
* <p>Returns {@code null} when the content-type is unknown.
* @return the content type
*/
public MediaType getContentType() {
String value = getFirst(CONTENT_TYPE);
return (value != null ? MediaType.parseMediaType(value) : null);
}
/**
* Sets the date and time at which the message was created, as specified by the {@code Date} header.
* <p>The date should be specified as the number of milliseconds since January 1, 1970 GMT.
* @param date the date
*/
public void setDate(long date) {
setDate(DATE, date);
}
/**
* Returns the date and time at which the message was created, as specified by the {@code Date} header.
* <p>The date is returned as the number of milliseconds since January 1, 1970 GMT. Returns -1 when the date is unknown.
* @return the creation date/time
* @throws IllegalArgumentException if the value can't be converted to a date
*/
public long getDate() {
return getFirstDate(DATE);
}
/**
* Sets the (new) entity tag of the body, as specified by the {@code ETag} header.
* @param eTag the new entity tag
*/
public void setETag(String eTag) {
set(ETAG, quote(eTag));
}
/**
* Returns the entity tag of the body, as specified by the {@code ETag} header.
* @return the entity tag
*/
public String getETag() {
return unquote(getFirst(ETAG));
}
/**
* Sets the date and time at which the message is no longer valid, as specified by the {@code Expires} header.
* <p>The date should be specified as the number of milliseconds since January 1, 1970 GMT.
* @param expires the new expires header value
*/
public void setExpires(long expires) {
setDate(EXPIRES, expires);
}
/**
* Returns the date and time at which the message is no longer valid, as specified by the {@code Expires} header.
* <p>The date is returned as the number of milliseconds since January 1, 1970 GMT. Returns -1 when the date is unknown.
* @return the expires value
*/
public long getExpires() {
return getFirstDate(EXPIRES);
}
/**
* Sets the (new) value of the {@code If-Modified-Since} header.
* <p>The date should be specified as the number of milliseconds since January 1, 1970 GMT.
* @param ifModifiedSince the new value of the header
*/
public void setIfModifiedSince(long ifModifiedSince) {
setDate(IF_MODIFIED_SINCE, ifModifiedSince);
}
/**
* Returns the value of the {@code IfModifiedSince} header.
* <p>The date is returned as the number of milliseconds since January 1, 1970 GMT. Returns -1 when the date is unknown.
* @return the header value
*/
public long getIfNotModifiedSince() {
return getFirstDate(IF_MODIFIED_SINCE);
}
/**
* Sets the (new) value of the {@code If-None-Match} header.
* @param ifNoneMatch the new value of the header
*/
public void setIfNoneMatch(String ifNoneMatch) {
set(IF_NONE_MATCH, quote(ifNoneMatch));
}
/**
* Sets the (new) values of the {@code If-None-Match} header.
* @param ifNoneMatchList the new value of the header
*/
public void setIfNoneMatch(List<String> ifNoneMatchList) {
StringBuilder builder = new StringBuilder();
for (Iterator<String> iterator = ifNoneMatchList.iterator(); iterator.hasNext();) {
String ifNoneMatch = iterator.next();
builder.append(quote(ifNoneMatch));
if (iterator.hasNext()) {
builder.append(", ");
}
}
set(IF_NONE_MATCH, builder.toString());
}
/**
* Returns the value of the {@code If-None-Match} header.
* @return the header value
*/
public List<String> getIfNoneMatch() {
List<String> result = new ArrayList<String>();
String value = getFirst(IF_NONE_MATCH);
if (value != null) {
String[] tokens = value.split(",\\s*");
for (String token : tokens) {
result.add(unquote(token));
}
}
return result;
}
/**
* Sets the time the resource was last changed, as specified by the {@code Last-Modified} header.
* <p>The date should be specified as the number of milliseconds since January 1, 1970 GMT.
* @param lastModified the last modified date
*/
public void setLastModified(long lastModified) {
setDate(LAST_MODIFIED, lastModified);
}
/**
* Returns the time the resource was last changed, as specified by the {@code Last-Modified} header.
* <p>The date is returned as the number of milliseconds since January 1, 1970 GMT. Returns -1 when the date is unknown.
* @return the last modified date
*/
public long getLastModified() {
return getFirstDate(LAST_MODIFIED);
}
/**
* Set the (new) location of a resource, as specified by the {@code Location} header.
* @param location the location
*/
public void setLocation(URI location) {
set(LOCATION, location.toASCIIString());
}
/**
* Return the (new) location of a resource, as specified by the {@code Location} header.
* <p>Returns {@code null} when the location is unknown.
* @return the location
*/
public URI getLocation() {
String value = getFirst(LOCATION);
return (value != null ? URI.create(value) : null);
}
/**
* Sets the (new) value of the {@code Pragma} header.
* @param pragma the value of the header
*/
public void setPragma(String pragma) {
set(PRAGMA, pragma);
}
/**
* Returns the value of the {@code Pragma} header.
* @return the value of the header
*/
public String getPragma() {
return getFirst(PRAGMA);
}
// Utility methods
private String quote(String s) {
Assert.notNull(s);
if (!s.startsWith("\"")) {
s = "\"" + s;
}
if (!s.endsWith("\"")) {
s = s + "\"";
}
return s;
}
private String unquote(String s) {
if (s == null) {
return null;
}
if (s.startsWith("\"")) {
s = s.substring(1);
}
if (s.endsWith("\"")) {
s = s.substring(0, s.length() - 1);
}
return s;
}
private long getFirstDate(String headerName) {
String headerValue = getFirst(headerName);
if (headerValue == null) {
return -1;
}
for (String dateFormat : DATE_FORMATS) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat, Locale.US);
simpleDateFormat.setTimeZone(GMT);
try {
return simpleDateFormat.parse(headerValue).getTime();
}
catch (ParseException e) {
// ignore
}
}
throw new IllegalArgumentException("Cannot parse date value \"" + headerValue +
"\" for \"" + headerName + "\" header");
}
private void setDate(String headerName, long date) {
SimpleDateFormat dateFormat = new SimpleDateFormat(DATE_FORMATS[0], Locale.US);
dateFormat.setTimeZone(GMT);
set(headerName, dateFormat.format(new Date(date)));
}
// Single string methods
/**
* Return the first header value for the given header name, if any.
* @param headerName the header name
* @return the first header value; or {@code null}
*/
public String getFirst(String headerName) {
List<String> headerValues = headers.get(headerName);
return headerValues != null ? headerValues.get(0) : null;
}
/**
* Add the given, single header value under the given name.
* @param headerName the header name
* @param headerValue the header value
* @throws UnsupportedOperationException if adding headers is not supported
* @see #put(String, List)
* @see #set(String, String)
*/
public void add(String headerName, String headerValue) {
List<String> headerValues = headers.get(headerName);
if (headerValues == null) {
headerValues = new LinkedList<String>();
this.headers.put(headerName, headerValues);
}
headerValues.add(headerValue);
}
/**
* Set the given, single header value under the given name.
* @param headerName the header name
* @param headerValue the header value
* @throws UnsupportedOperationException if adding headers is not supported
* @see #put(String, List)
* @see #add(String, String)
*/
public void set(String headerName, String headerValue) {
List<String> headerValues = new LinkedList<String>();
headerValues.add(headerValue);
headers.put(headerName, headerValues);
}
public void setAll(Map<String, String> values) {
for (Entry<String, String> entry : values.entrySet()) {
set(entry.getKey(), entry.getValue());
}
}
public Map<String, String> toSingleValueMap() {
LinkedHashMap<String, String> singleValueMap = new LinkedHashMap<String,String>(this.headers.size());
for (Entry<String, List<String>> entry : headers.entrySet()) {
singleValueMap.put(entry.getKey(), entry.getValue().get(0));
}
return singleValueMap;
}
// Map implementation
public int size() {
return this.headers.size();
}
public boolean isEmpty() {
return this.headers.isEmpty();
}
public boolean containsKey(Object key) {
return this.headers.containsKey(key);
}
public boolean containsValue(Object value) {
return this.headers.containsValue(value);
}
public List<String> get(Object key) {
return this.headers.get(key);
}
public List<String> put(String key, List<String> value) {
return this.headers.put(key, value);
}
public List<String> remove(Object key) {
return this.headers.remove(key);
}
public void putAll(Map<? extends String, ? extends List<String>> m) {
this.headers.putAll(m);
}
public void clear() {
this.headers.clear();
}
public Set<String> keySet() {
return this.headers.keySet();
}
public Collection<List<String>> values() {
return this.headers.values();
}
public Set<Entry<String, List<String>>> entrySet() {
return this.headers.entrySet();
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof HttpHeaders)) {
return false;
}
HttpHeaders otherHeaders = (HttpHeaders) other;
return this.headers.equals(otherHeaders.headers);
}
@Override
public int hashCode() {
return this.headers.hashCode();
}
@Override
public String toString() {
return this.headers.toString();
}
}
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