/*
* ====================================================================
* 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.util.NoSuchElementException;
import org.apache.http.FormattedHeader;
import org.apache.http.Header;
import org.apache.http.HeaderElement;
import org.apache.http.HeaderElementIterator;
import org.apache.http.HeaderIterator;
import org.apache.http.annotation.NotThreadSafe;
import org.apache.http.util.CharArrayBuffer;
/**
* Basic implementation of a {@link HeaderElementIterator}.
*
* @since 4.0
*/
@NotThreadSafe
public class BasicHeaderElementIterator implements HeaderElementIterator {
private final HeaderIterator headerIt;
private final HeaderValueParser parser;
private HeaderElement currentElement = null;
private CharArrayBuffer buffer = null;
private ParserCursor cursor = null;
/**
* Creates a new instance of BasicHeaderElementIterator
*/
public BasicHeaderElementIterator(
final HeaderIterator headerIterator,
final HeaderValueParser parser) {
if (headerIterator == null) {
throw new IllegalArgumentException("Header iterator may not be null");
}
if (parser == null) {
throw new IllegalArgumentException("Parser may not be null");
}
this.headerIt = headerIterator;
this.parser = parser;
}
public BasicHeaderElementIterator(final HeaderIterator headerIterator) {
this(headerIterator, BasicHeaderValueParser.DEFAULT);
}
private void bufferHeaderValue() {
this.cursor = null;
this.buffer = null;
while (this.headerIt.hasNext()) {
Header h = this.headerIt.nextHeader();
if (h instanceof FormattedHeader) {
this.buffer = ((FormattedHeader) h).getBuffer();
this.cursor = new ParserCursor(0, this.buffer.length());
this.cursor.updatePos(((FormattedHeader) h).getValuePos());
break;
} else {
String value = h.getValue();
if (value != null) {
this.buffer = new CharArrayBuffer(value.length());
this.buffer.append(value);
this.cursor = new ParserCursor(0, this.buffer.length());
break;
}
}
}
}
private void parseNextElement() {
// loop while there are headers left to parse
while (this.headerIt.hasNext() || this.cursor != null) {
if (this.cursor == null || this.cursor.atEnd()) {
// get next header value
bufferHeaderValue();
}
// Anything buffered?
if (this.cursor != null) {
// loop while there is data in the buffer
while (!this.cursor.atEnd()) {
HeaderElement e = this.parser.parseHeaderElement(this.buffer, this.cursor);
if (!(e.getName().length() == 0 && e.getValue() == null)) {
// Found something
this.currentElement = e;
return;
}
}
// if at the end of the buffer
if (this.cursor.atEnd()) {
// discard it
this.cursor = null;
this.buffer = null;
}
}
}
}
public boolean hasNext() {
if (this.currentElement == null) {
parseNextElement();
}
return this.currentElement != null;
}
public HeaderElement nextElement() throws NoSuchElementException {
if (this.currentElement == null) {
parseNextElement();
}
if (this.currentElement == null) {
throw new NoSuchElementException("No more header elements available");
}
HeaderElement element = this.currentElement;
this.currentElement = null;
return element;
}
public final HeaderElement next() throws NoSuchElementException {
return nextElement();
}
public void remove() throws UnsupportedOperationException {
throw new UnsupportedOperationException("Remove not supported");
}
}