/**
* 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.processor.mllp;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.Processor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.camel.component.mllp.MllpConstants.MLLP_ACKNOWLEDGEMENT;
import static org.apache.camel.component.mllp.MllpConstants.MLLP_ACKNOWLEDGEMENT_TYPE;
import static org.apache.camel.component.mllp.MllpEndpoint.MESSAGE_TERMINATOR;
import static org.apache.camel.component.mllp.MllpEndpoint.SEGMENT_DELIMITER;
/**
* A Camel Processor for generating HL7 Acknowledgements
*/
public class Hl7AcknowledgementGenerator implements Processor {
private static final Logger LOG = LoggerFactory.getLogger(Hl7AcknowledgementGenerator.class);
String defaultNack = "MSH|^~\\&|||||||NACK||P|2.2" + SEGMENT_DELIMITER
+ "MSA|AR|" + SEGMENT_DELIMITER
+ MESSAGE_TERMINATOR;
@Override
public void process(Exchange exchange) throws Exception {
Message message;
if (exchange.hasOut()) {
message = exchange.getOut();
} else {
message = exchange.getIn();
}
byte[] hl7Bytes = message.getMandatoryBody(byte[].class);
byte[] acknowledgementBytes = null;
if (null == exchange.getException()) {
acknowledgementBytes = generateApplicationAcceptAcknowledgementMessage(hl7Bytes);
exchange.setProperty(MLLP_ACKNOWLEDGEMENT_TYPE, "AA");
} else {
acknowledgementBytes = generateApplicationErrorAcknowledgementMessage(hl7Bytes);
exchange.setProperty(MLLP_ACKNOWLEDGEMENT_TYPE, "AE");
}
exchange.setProperty(MLLP_ACKNOWLEDGEMENT, acknowledgementBytes);
}
public byte[] generateApplicationAcceptAcknowledgementMessage(byte[] hl7MessageBytes) throws Hl7AcknowledgementGenerationException {
return generateAcknowledgementMessage(hl7MessageBytes, "AA");
}
public byte[] generateApplicationRejectAcknowledgementMessage(byte[] hl7MessageBytes) throws Hl7AcknowledgementGenerationException {
return generateAcknowledgementMessage(hl7MessageBytes, "AR");
}
public byte[] generateApplicationErrorAcknowledgementMessage(byte[] hl7MessageBytes) throws Hl7AcknowledgementGenerationException {
return generateAcknowledgementMessage(hl7MessageBytes, "AE");
}
byte[] generateAcknowledgementMessage(byte[] hl7MessageBytes, String acknowledgementCode) throws Hl7AcknowledgementGenerationException {
if (hl7MessageBytes == null) {
throw new Hl7AcknowledgementGenerationException("Null HL7 message received for parsing operation");
}
final byte fieldSeparator = hl7MessageBytes[3];
final byte componentSeparator = hl7MessageBytes[4];
List<Integer> fieldSeparatorIndexes = new ArrayList<>(10); // We need at least 10 fields to create the acknowledgment
// Find the end of the MSH and indexes of the fields in the MSH
int endOfMSH = -1;
for (int i = 0; i < hl7MessageBytes.length; ++i) {
if (fieldSeparator == hl7MessageBytes[i]) {
fieldSeparatorIndexes.add(i);
} else if (SEGMENT_DELIMITER == hl7MessageBytes[i]) {
endOfMSH = i;
break;
}
}
if (-1 == endOfMSH) {
throw new Hl7AcknowledgementGenerationException("Failed to find the end of the MSH Segment while attempting to generate response", hl7MessageBytes);
}
if (8 > fieldSeparatorIndexes.size()) {
throw new Hl7AcknowledgementGenerationException("Insufficient number of fields in after MSH-2 in MSH to generate a response - 8 are required but "
+ fieldSeparatorIndexes.size() + " " + "were found", hl7MessageBytes);
}
// Build the MSH Segment
ByteArrayOutputStream acknowledgement = new ByteArrayOutputStream(1024);
acknowledgement.write(hl7MessageBytes, 0, fieldSeparatorIndexes.get(1)); // through MSH-2 (without trailing field separator)
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(3), fieldSeparatorIndexes.get(4) - fieldSeparatorIndexes.get(3)); // MSH-5
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(4), fieldSeparatorIndexes.get(5) - fieldSeparatorIndexes.get(4)); // MSH-6
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(1), fieldSeparatorIndexes.get(2) - fieldSeparatorIndexes.get(1)); // MSH-3
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(2), fieldSeparatorIndexes.get(3) - fieldSeparatorIndexes.get(2)); // MSH-4
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(5), fieldSeparatorIndexes.get(7) - fieldSeparatorIndexes.get(5)); // MSH-7 and MSH-8
// Need to generate the correct MSH-9
acknowledgement.write(fieldSeparator);
acknowledgement.write("ACK".getBytes(), 0, 3); // MSH-9.1
int msh92start = -1;
for (int j = fieldSeparatorIndexes.get(7) + 1; j < fieldSeparatorIndexes.get(8); ++j) {
if (componentSeparator == hl7MessageBytes[j]) {
msh92start = j;
break;
}
}
if (-1 == msh92start) {
LOG.warn("Didn't find component separator for MSH-9.2 - sending ACK in MSH-9");
} else {
acknowledgement.write(hl7MessageBytes, msh92start, fieldSeparatorIndexes.get(8) - msh92start); // MSH-9.2
}
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(8), endOfMSH - fieldSeparatorIndexes.get(8)); // MSH-10 through the end of the MSH
acknowledgement.write(SEGMENT_DELIMITER);
// Build the MSA Segment
acknowledgement.write("MSA".getBytes(), 0, 3);
acknowledgement.write(fieldSeparator);
acknowledgement.write(acknowledgementCode.getBytes(), 0, 2);
acknowledgement.write(hl7MessageBytes, fieldSeparatorIndexes.get(8), fieldSeparatorIndexes.get(9) - fieldSeparatorIndexes.get(8)); // MSH-10 end
acknowledgement.write(SEGMENT_DELIMITER);
// Terminate the message
acknowledgement.write(SEGMENT_DELIMITER);
acknowledgement.write(MESSAGE_TERMINATOR);
return acknowledgement.toByteArray();
}
}