ca.uhn.hl7v2.parser.GenericParser Maven / Gradle / Ivy
/**
The contents of this file are subject to the Mozilla Public License Version 1.1
(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.mozilla.org/MPL/
Software distributed under the License is distributed on an "AS IS" basis,
WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the
specific language governing rights and limitations under the License.
The Original Code is "GroupPointer.java". Description:
"A GroupPointer is used when parsing traditionally encoded HL7 messages"
The Initial Developer of the Original Code is University Health Network. Copyright (C)
2001. All Rights Reserved.
Contributor(s): ______________________________________.
Alternatively, the contents of this file may be used under the terms of the
GNU General Public License (the �GPL�), in which case the provisions of the GPL are
applicable instead of those above. If you wish to allow use of your version of this
file only under the terms of the GPL and not to allow others to use your version
of this file under the MPL, indicate your decision by deleting the provisions above
and replace them with the notice and other provisions required by the GPL License.
If you do not delete the provisions above, a recipient may use your version of
this file under either the MPL or the GPL.
*/
package ca.uhn.hl7v2.parser;
import ca.uhn.hl7v2.HL7Exception;
import ca.uhn.hl7v2.model.Message;
import ca.uhn.hl7v2.model.Segment;
import ca.uhn.hl7v2.model.Type;
import ca.uhn.hl7v2.validation.ValidationContext;
/**
* A Parser that delegates parsing tasks to an underlying PipeParser and DefaultXMLParser
* as needed. Messages to be parsed are inspected in order to determine which Parser
* to use. If a message is to be encoded, the "primary" Parser will be used. The
* primary parser defaults to PipeParser, and can be configured using the
* set...AsPrimary() methods.
* @author Bryan Tripp
*/
public class GenericParser extends Parser {
private Parser primaryParser;
private Parser secondaryParser;
private final PipeParser pipeParser;
private final XMLParser xmlParser;
/** Creates a new instance of GenericParser */
public GenericParser() {
this(null);
}
/**
* Creates a new instance of GenericParser
*
* @param theFactory custom factory to use for model class lookup
*/
public GenericParser(ModelClassFactory theFactory) {
super(theFactory);
pipeParser = new PipeParser(theFactory);
xmlParser = new DefaultXMLParser(theFactory);
setPipeParserAsPrimary();
}
/**
* Sets the underlying XMLParser as the primary parser, so that subsequent calls to
* encode() will return XML encoded messages, and an attempt will be made to use the
* XMLParser first for parsing.
*/
public void setXMLParserAsPrimary() {
primaryParser = xmlParser;
secondaryParser = pipeParser;
}
/**
* Sets the underlying PipeParser as the primary parser, so that subsequent calls to
* encode() will return traditionally encoded messages, and an attempt will be made to use the
* PipeParser first for parsing. This is the default setting.
*/
public void setPipeParserAsPrimary() {
primaryParser = pipeParser;
secondaryParser = xmlParser;
}
/**
* @param theContext the set of validation rules to be applied to messages parsed or
* encoded by this parser (defaults to ValidationContextFactory.DefaultValidation)
*/
public void setValidationContext(ValidationContext theContext) {
super.setValidationContext(theContext);
// These parsers are not yet initialized when this is called during the Parser constructor
if (xmlParser != null) {
pipeParser.setValidationContext(theContext);
xmlParser.setValidationContext(theContext);
}
}
/**
* Checks the encoding of the message using getEncoding(), and returns the corresponding
* parser (either pipeParser or xmlParser). If the encoding is not recognized an
* HL7Exception is thrown.
*/
private Parser getAppropriateParser(String message) throws HL7Exception {
String encoding = getEncoding(message);
if (encoding == null)
encoding = ""; //prevent null pointer exception
Parser appropriateParser = null;
if (encoding.equalsIgnoreCase("VB")) {
appropriateParser = pipeParser;
}
else if (encoding.equalsIgnoreCase("XML")) {
appropriateParser = xmlParser;
}
else {
throw new HL7Exception(
"Can't find appropriate parser - encoding not recognized",
HL7Exception.APPLICATION_INTERNAL_ERROR);
}
return appropriateParser;
}
/**
* Formats a Message object into an HL7 message string using the given
* encoding.
* @throws HL7Exception if the data fields in the message do not permit encoding
* (e.g. required fields are null)
* @throws EncodingNotSupportedException if the requested encoding is not
* supported by this parser.
*/
protected String doEncode(Message source, String encoding) throws HL7Exception, EncodingNotSupportedException {
String ret = null;
if (encoding == null)
encoding = ""; //prevent null pointer exception
if (encoding.equalsIgnoreCase("VB")) {
ret = pipeParser.doEncode(source);
}
else if (encoding.equalsIgnoreCase("XML")) {
ret = xmlParser.doEncode(source);
}
else {
throw new EncodingNotSupportedException(
"The encoding " + encoding + " is not supported by " + this.getClass().getName());
}
return ret;
}
/**
* Returns a minimal amount of data from a message string, including only the
* data needed to send a response to the remote system. This includes the
* following fields:
*
- field separator
* - encoding characters
* - processing ID
* - message control ID
* This method is intended for use when there is an error parsing a message,
* (so the Message object is unavailable) but an error message must be sent
* back to the remote system including some of the information in the inbound
* message. This method parses only that required information, hopefully
* avoiding the condition that caused the original error.
*/
public Segment getCriticalResponseData(String message) throws HL7Exception {
return getAppropriateParser(message).getCriticalResponseData(message);
}
/**
* Returns the version ID (MSH-12) from the given message, without fully parsing the message.
* The version is needed prior to parsing in order to determine the message class
* into which the text of the message should be parsed.
* @throws HL7Exception if the version field can not be found.
*/
public String getVersion(String message) throws HL7Exception {
return getAppropriateParser(message).getVersion(message);
}
/**
* Returns a String representing the encoding of the given message, if
* the encoding is recognized. For example if the given message appears
* to be encoded using HL7 2.x XML rules then "XML" would be returned.
* If the encoding is not recognized then null is returned. That this
* method returns a specific encoding does not guarantee that the
* message is correctly encoded (e.g. well formed XML) - just that
* it is not encoded using any other encoding than the one returned.
* Returns null if the encoding is not recognized.
*/
public String getEncoding(String message) {
String encoding = primaryParser.getEncoding(message);
if (encoding == null)
encoding = secondaryParser.getEncoding(message);
return encoding;
}
/**
* For response messages, returns the value of MSA-2 (the message ID of the message
* sent by the sending system). This value may be needed prior to main message parsing,
* so that (particularly in a multi-threaded scenario) the message can be routed to
* the thread that sent the request. We need this information first so that any
* parse exceptions are thrown to the correct thread. Implementers of Parsers should
* take care to make the implementation of this method very fast and robust.
* Returns null if MSA-2 can not be found (e.g. if the message is not a
* response message).
*/
public String getAckID(String message) {
try {
return getAppropriateParser(message).getAckID(message);
}
catch (HL7Exception e) {
return null;
}
}
/**
* Returns true if and only if the given encoding is supported
* by this Parser.
*/
public boolean supportsEncoding(String encoding) {
boolean supported = false;
if ("VB".equalsIgnoreCase(encoding) || "XML".equalsIgnoreCase(encoding))
supported = true;
return supported;
}
/**
* @return the preferred encoding of the current primary Parser
*/
public String getDefaultEncoding() {
return primaryParser.getDefaultEncoding();
}
/**
* Parses a message string and returns the corresponding Message
* object.
* @throws HL7Exception if the message is not correctly formatted.
* @throws EncodingNotSupportedException if the message encoded
* is not supported by this parser.
*/
protected Message doParse(String message, String version) throws HL7Exception, EncodingNotSupportedException {
return getAppropriateParser(message).doParse(message, version);
}
/**
* Formats a Message object into an HL7 message string using this parser's
* default encoding.
* @throws HL7Exception if the data fields in the message do not permit encoding
* (e.g. required fields are null)
*/
protected String doEncode(Message source) throws HL7Exception {
return primaryParser.doEncode(source);
}
/**
* {@inheritDoc }
*/
@Override
public String doEncode(Segment structure, EncodingCharacters encodingCharacters) throws HL7Exception {
return primaryParser.doEncode(structure, encodingCharacters);
}
/**
* {@inheritDoc }
*/
@Override
public String doEncode(Type type, EncodingCharacters encodingCharacters) throws HL7Exception {
return primaryParser.doEncode(type, encodingCharacters);
}
/**
* {@inheritDoc }
*/
@Override
public void parse(Type type, String string, EncodingCharacters encodingCharacters) throws HL7Exception {
primaryParser.parse(type, string, encodingCharacters);
}
/**
* {@inheritDoc }
*/
@Override
public void parse(Segment segment, String string, EncodingCharacters encodingCharacters) throws HL7Exception {
primaryParser.parse(segment, string, encodingCharacters);
}
@Override
public void parse(Message message, String string) throws HL7Exception {
primaryParser.parse(message, string);
}
}