/**
* 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.
*/
package org.apache.camel.util;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.Scanner;
import org.apache.camel.CamelContext;
import org.apache.camel.Exchange;
import org.apache.camel.NoTypeConversionAvailableException;
/**
* Group based {@link Iterator} which groups the given {@link Iterator} a number of times
* and then return a combined response as a String.
* <p/>
* This implementation uses as internal byte array buffer, to combine the response.
* The token is inserted between the individual parts.
* <p/>
* For example if you group by new line, then a new line token is inserted between the lines.
*/
public final class GroupIterator implements Iterator<Object>, Closeable {
private final CamelContext camelContext;
private final Exchange exchange;
private final Iterator<?> it;
private final String token;
private final int group;
private boolean closed;
private final ByteArrayOutputStream bos = new ByteArrayOutputStream();
/**
* Creates a new group iterator
*
* @param camelContext the camel context
* @param it the iterator to group
* @param token then token used to separate between the parts, use <tt>null</tt> to not add the token
* @param group number of parts to group together
* @throws IllegalArgumentException is thrown if group is not a positive number
* @deprecated Please use GroupIterator(Exchange exchange, Iterator<?> it, String token, int group) instead
*/
@Deprecated
public GroupIterator(CamelContext camelContext, Iterator<?> it, String token, int group) {
this.exchange = null;
this.camelContext = camelContext;
this.it = it;
this.token = token;
this.group = group;
if (group <= 0) {
throw new IllegalArgumentException("Group must be a positive number, was: " + group);
}
}
/**
* Creates a new group iterator
*
* @param exchange the exchange used to create this group iterator
* @param it the iterator to group
* @param token then token used to separate between the parts, use <tt>null</tt> to not add the token
* @param group number of parts to group together
* @throws IllegalArgumentException is thrown if group is not a positive number
*/
public GroupIterator(Exchange exchange, Iterator<?> it, String token, int group) {
this.exchange = exchange;
this.camelContext = exchange.getContext();
this.it = it;
this.token = token;
this.group = group;
if (group <= 0) {
throw new IllegalArgumentException("Group must be a positive number, was: " + group);
}
}
@Override
public void close() throws IOException {
try {
if (it instanceof Scanner) {
// special for Scanner which implement the Closeable since JDK7
Scanner scanner = (Scanner) it;
scanner.close();
IOException ioException = scanner.ioException();
if (ioException != null) {
throw ioException;
}
} else if (it instanceof Closeable) {
IOHelper.closeWithException((Closeable) it);
}
} finally {
// close the buffer as well
bos.close();
// we are now closed
closed = true;
}
}
@Override
public boolean hasNext() {
if (closed) {
return false;
}
boolean answer = it.hasNext();
if (!answer) {
// auto close
try {
close();
} catch (IOException e) {
// ignore
}
}
return answer;
}
@Override
public Object next() {
try {
return doNext();
} catch (Exception e) {
throw ObjectHelper.wrapRuntimeCamelException(e);
}
}
private Object doNext() throws IOException, NoTypeConversionAvailableException {
int count = 0;
Object data = "";
while (count < group && it.hasNext()) {
data = it.next();
// include token in between
if (data != null && count > 0 && token != null) {
bos.write(token.getBytes());
}
if (data instanceof InputStream) {
InputStream is = (InputStream) data;
IOHelper.copy(is, bos);
} else if (data instanceof byte[]) {
byte[] bytes = (byte[]) data;
bos.write(bytes);
} else if (data != null) {
// convert to input stream
InputStream is = camelContext.getTypeConverter().mandatoryConvertTo(InputStream.class, data);
IOHelper.copy(is, bos);
}
count++;
}
// prepare and return answer as String using exchange's charset
String answer = bos.toString(IOHelper.getCharsetName(exchange));
bos.reset();
return answer;
}
@Override
public void remove() {
it.remove();
}
}