/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.message;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import org.apache.http.Header;
import org.apache.http.HeaderIterator;
import org.apache.http.annotation.NotThreadSafe;
import org.apache.http.util.CharArrayBuffer;
/**
* A class for combining a set of headers.
* This class allows for multiple headers with the same name and
* keeps track of the order in which headers were added.
*
*
* @since 4.0
*/
@NotThreadSafe
public class HeaderGroup implements Cloneable, Serializable {
private static final long serialVersionUID = 2608834160639271617L;
private final Header[] EMPTY = new Header[] {};
/** The list of headers for this group, in the order in which they were added */
private final List<Header> headers;
/**
* Constructor for HeaderGroup.
*/
public HeaderGroup() {
this.headers = new ArrayList<Header>(16);
}
/**
* Removes any contained headers.
*/
public void clear() {
headers.clear();
}
/**
* Adds the given header to the group. The order in which this header was
* added is preserved.
*
* @param header the header to add
*/
public void addHeader(final Header header) {
if (header == null) {
return;
}
headers.add(header);
}
/**
* Removes the given header.
*
* @param header the header to remove
*/
public void removeHeader(final Header header) {
if (header == null) {
return;
}
headers.remove(header);
}
/**
* Replaces the first occurence of the header with the same name. If no header with
* the same name is found the given header is added to the end of the list.
*
* @param header the new header that should replace the first header with the same
* name if present in the list.
*/
public void updateHeader(final Header header) {
if (header == null) {
return;
}
// HTTPCORE-361 : we don't use the for-each syntax, i.e.
// for (Header header : headers)
// as that creates an Iterator that needs to be garbage-collected
for (int i = 0; i < this.headers.size(); i++) {
final Header current = this.headers.get(i);
if (current.getName().equalsIgnoreCase(header.getName())) {
this.headers.set(i, header);
return;
}
}
this.headers.add(header);
}
/**
* Sets all of the headers contained within this group overriding any
* existing headers. The headers are added in the order in which they appear
* in the array.
*
* @param headers the headers to set
*/
public void setHeaders(final Header[] headers) {
clear();
if (headers == null) {
return;
}
Collections.addAll(this.headers, headers);
}
/**
* Gets a header representing all of the header values with the given name.
* If more that one header with the given name exists the values will be
* combined with a "," as per RFC 2616.
*
* <p>Header name comparison is case insensitive.
*
* @param name the name of the header(s) to get
* @return a header with a condensed value or {@code null} if no
* headers by the given name are present
*/
public Header getCondensedHeader(final String name) {
final Header[] hdrs = getHeaders(name);
if (hdrs.length == 0) {
return null;
} else if (hdrs.length == 1) {
return hdrs[0];
} else {
final CharArrayBuffer valueBuffer = new CharArrayBuffer(128);
valueBuffer.append(hdrs[0].getValue());
for (int i = 1; i < hdrs.length; i++) {
valueBuffer.append(", ");
valueBuffer.append(hdrs[i].getValue());
}
return new BasicHeader(name.toLowerCase(Locale.ROOT), valueBuffer.toString());
}
}
/**
* Gets all of the headers with the given name. The returned array
* maintains the relative order in which the headers were added.
*
* <p>Header name comparison is case insensitive.
*
* @param name the name of the header(s) to get
*
* @return an array of length ≥ 0
*/
public Header[] getHeaders(final String name) {
List<Header> headersFound = null;
// HTTPCORE-361 : we don't use the for-each syntax, i.e.
// for (Header header : headers)
// as that creates an Iterator that needs to be garbage-collected
for (int i = 0; i < this.headers.size(); i++) {
final Header header = this.headers.get(i);
if (header.getName().equalsIgnoreCase(name)) {
if (headersFound == null) {
headersFound = new ArrayList<Header>();
}
headersFound.add(header);
}
}
return headersFound != null ? headersFound.toArray(new Header[headersFound.size()]) : EMPTY;
}
/**
* Gets the first header with the given name.
*
* <p>Header name comparison is case insensitive.
*
* @param name the name of the header to get
* @return the first header or {@code null}
*/
public Header getFirstHeader(final String name) {
// HTTPCORE-361 : we don't use the for-each syntax, i.e.
// for (Header header : headers)
// as that creates an Iterator that needs to be garbage-collected
for (int i = 0; i < this.headers.size(); i++) {
final Header header = this.headers.get(i);
if (header.getName().equalsIgnoreCase(name)) {
return header;
}
}
return null;
}
/**
* Gets the last header with the given name.
*
* <p>Header name comparison is case insensitive.
*
* @param name the name of the header to get
* @return the last header or {@code null}
*/
public Header getLastHeader(final String name) {
// start at the end of the list and work backwards
for (int i = headers.size() - 1; i >= 0; i--) {
final Header header = headers.get(i);
if (header.getName().equalsIgnoreCase(name)) {
return header;
}
}
return null;
}
/**
* Gets all of the headers contained within this group.
*
* @return an array of length ≥ 0
*/
public Header[] getAllHeaders() {
return headers.toArray(new Header[headers.size()]);
}
/**
* Tests if headers with the given name are contained within this group.
*
* <p>Header name comparison is case insensitive.
*
* @param name the header name to test for
* @return {@code true} if at least one header with the name is
* contained, {@code false} otherwise
*/
public boolean containsHeader(final String name) {
// HTTPCORE-361 : we don't use the for-each syntax, i.e.
// for (Header header : headers)
// as that creates an Iterator that needs to be garbage-collected
for (int i = 0; i < this.headers.size(); i++) {
final Header header = this.headers.get(i);
if (header.getName().equalsIgnoreCase(name)) {
return true;
}
}
return false;
}
/**
* Returns an iterator over this group of headers.
*
* @return iterator over this group of headers.
*
* @since 4.0
*/
public HeaderIterator iterator() {
return new BasicListHeaderIterator(this.headers, null);
}
/**
* Returns an iterator over the headers with a given name in this group.
*
* @param name the name of the headers over which to iterate, or
* {@code null} for all headers
*
* @return iterator over some headers in this group.
*
* @since 4.0
*/
public HeaderIterator iterator(final String name) {
return new BasicListHeaderIterator(this.headers, name);
}
/**
* Returns a copy of this object
*
* @return copy of this object
*
* @since 4.0
*/
public HeaderGroup copy() {
final HeaderGroup clone = new HeaderGroup();
clone.headers.addAll(this.headers);
return clone;
}
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
@Override
public String toString() {
return this.headers.toString();
}
}