/*
* Copyright 2002-2017 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.integration.stream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.springframework.integration.context.IntegrationObjectSupport;
import org.springframework.integration.core.MessageSource;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessagingException;
import org.springframework.messaging.support.GenericMessage;
/**
* A pollable source for receiving bytes from an {@link InputStream}.
*
* @author Mark Fisher
* @author Artem Bilan
*/
public class ByteStreamReadingMessageSource extends IntegrationObjectSupport implements MessageSource<byte[]> {
private BufferedInputStream stream;
private Object streamMonitor;
private int bytesPerMessage = 1024;
private boolean shouldTruncate = true;
public ByteStreamReadingMessageSource(InputStream stream) {
this(stream, -1);
}
public ByteStreamReadingMessageSource(InputStream stream, int bufferSize) {
this.streamMonitor = stream;
if (stream instanceof BufferedInputStream) {
this.stream = (BufferedInputStream) stream;
}
else if (bufferSize > 0) {
this.stream = new BufferedInputStream(stream, bufferSize);
}
else {
this.stream = new BufferedInputStream(stream);
}
}
public void setBytesPerMessage(int bytesPerMessage) {
this.bytesPerMessage = bytesPerMessage;
}
public void setShouldTruncate(boolean shouldTruncate) {
this.shouldTruncate = shouldTruncate;
}
@Override
public String getComponentType() {
return "stream:stdin-channel-adapter(byte)";
}
public Message<byte[]> receive() {
try {
byte[] bytes;
int bytesRead = 0;
synchronized (this.streamMonitor) {
if (this.stream.available() == 0) {
return null;
}
bytes = new byte[this.bytesPerMessage];
bytesRead = this.stream.read(bytes, 0, bytes.length);
}
if (bytesRead <= 0) {
return null;
}
if (!this.shouldTruncate) {
return new GenericMessage<byte[]>(bytes);
}
else {
byte[] result = new byte[bytesRead];
System.arraycopy(bytes, 0, result, 0, result.length);
return new GenericMessage<byte[]>(result);
}
}
catch (IOException e) {
throw new MessagingException("IO failure occurred in adapter", e);
}
}
}