ca.uhn.hl7v2.util.Hl7InputStreamMessageIterator Maven / Gradle / Ivy
package ca.uhn.hl7v2.util;
import java.io.InputStream;
import java.io.Reader;
import java.util.Iterator;
import ca.uhn.hl7v2.DefaultHapiContext;
import ca.uhn.hl7v2.HL7Exception;
import ca.uhn.hl7v2.HapiContext;
import ca.uhn.hl7v2.HapiContextSupport;
import ca.uhn.hl7v2.model.Message;
import ca.uhn.hl7v2.parser.EncodingNotSupportedException;
import ca.uhn.hl7v2.util.Hl7InputStreamMessageStringIterator.ParseFailureError;
import ca.uhn.hl7v2.validation.impl.ValidationContextFactory;
/**
*
* Reads from an {@link InputStream} containing a stream of encoded HL7 messages
* and iterates over those messages. This class is geared towards reading from
* files, and tries to be very lenient about the format of the stream,
* specifically concerning control characters and line endings. It should be
* safe to provide a stream containing Windows or Unix line endings (which will
* be treated as segment delimiters). It is also safe to provide a stream containing
* MLLP control blocks before and after each message (although these will not be
* validated! Do not use this class to read MLLP messages from a socket stream!)
*
*
* The input stream could, for example, be a FileInputStream reading from a text
* file containing a number of HL7 messages in plain text format.
*
*
* Usage note: If an IOException occurs while reading from the stream or a
* message parsing exception occurs, it will be thrown as an unchecked
* {@link ParseFailureError}
*
*/
public class Hl7InputStreamMessageIterator extends HapiContextSupport implements Iterator {
private Class myMessageType;
private Hl7InputStreamMessageStringIterator myWrapped;
/**
* Constructor
*
* @param theInputStream
* The input stream to read from
*/
public Hl7InputStreamMessageIterator(InputStream theInputStream) {
this(theInputStream, new DefaultHapiContext(ValidationContextFactory.noValidation()));
}
/**
* Constructor
*
* @param theReader
* The reader to read from
*/
public Hl7InputStreamMessageIterator(Reader theReader) {
this(theReader, new DefaultHapiContext(ValidationContextFactory.noValidation()));
}
/**
* Constructor
*
* @param theInputStream
* The input stream to read from
* @param theHapiContext
* The HapiContext from which to obtain the parser
*/
public Hl7InputStreamMessageIterator(InputStream theInputStream, HapiContext theHapiContext) {
super(theHapiContext);
myWrapped = new Hl7InputStreamMessageStringIterator(theInputStream);
}
/**
* Constructor
*
* @param theReader
* The reader to read from
* @param theHapiContext
* The HapiContext from which to obtain the parser
*/
public Hl7InputStreamMessageIterator(Reader theReader, HapiContext theHapiContext) {
super(theHapiContext);
myWrapped = new Hl7InputStreamMessageStringIterator(theReader);
}
/**
* Factory method which returns an instance which reads from a file on the
* classpath
*/
public static Hl7InputStreamMessageIterator getForClasspathResource(String theClasspath) {
InputStream is = Hl7InputStreamMessageIterator.class.getResourceAsStream(theClasspath);
if (is == null) {
throw new IllegalArgumentException("Can't find resource: " + theClasspath);
}
return new Hl7InputStreamMessageIterator(is);
}
/**
* {@inheritDoc}
*/
public boolean hasNext() {
return myWrapped.hasNext();
}
/**
* {@inheritDoc}
*/
public Message next() {
String nextString = myWrapped.next();
Message retVal;
try {
if (myMessageType != null) {
retVal = ReflectionUtil.instantiateMessage(myMessageType, getHapiContext().getModelClassFactory());
retVal.parse(nextString);
} else {
retVal = getHapiContext().getPipeParser().parse(nextString);
}
} catch (EncodingNotSupportedException e) {
throw new Hl7InputStreamMessageStringIterator.ParseFailureError("Failed to parse message", e);
} catch (HL7Exception e) {
throw new Hl7InputStreamMessageStringIterator.ParseFailureError("Failed to parse message", e);
}
return retVal;
}
/**
* Unsupported method!
*
* @throws UnsupportedOperationException
* If called
*/
public void remove() {
throw new UnsupportedOperationException();
}
/**
* If set to true, any lines beginning with a hash (#) will be ignored. This allows
* you to place comments in a file to be read if needed.
*/
public void setIgnoreComments(boolean theIgnoreComments) {
myWrapped.setIgnoreComments(theIgnoreComments);
}
/**
* If set (default is null), all messages will be parsed into
* instances of this type.
*/
public void setMessageType(Class theMessageType) {
myMessageType = theMessageType;
}
}