org.apache.camel.support.InputStreamIterator Maven / Gradle / Ivy
/*
* 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.support;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import org.apache.camel.NoTypeConversionAvailableException;
import org.apache.camel.TypeConverter;
/**
* An {@link InputStream} that wraps an {@link Iterator} which reads iterations as byte array data.
*/
public final class InputStreamIterator extends InputStream {
private final TypeConverter converter;
private final Iterator it;
private InputStream chunk;
public InputStreamIterator(TypeConverter converter, Iterator it) {
this.converter = converter;
this.it = it;
}
@Override
public int read() throws IOException {
if (chunk == null) {
chunk = nextChunk();
}
if (chunk == null) {
return -1;
}
int data = chunk.read();
if (data == -1) {
// initialize for next chunk
chunk = null;
return read();
}
return data;
}
@Override
public int available() throws IOException {
if (chunk == null) {
chunk = nextChunk();
}
return chunk != null ? chunk.available() : 0;
}
private InputStream nextChunk() throws IOException {
if (it.hasNext()) {
try {
byte[] buf = converter.mandatoryConvertTo(byte[].class, it.next());
return new ByteArrayInputStream(buf);
} catch (NoTypeConversionAvailableException e) {
throw new IOException(e);
}
} else {
return null;
}
}
}