ca.uhn.hl7v2.parser.XMLParser 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 "XMLParser.java". Description:
* "Parses and encodes HL7 messages in XML form, according to HL7's normative XML encoding
* specification."
*
* The Initial Developer of the Original Code is University Health Network. Copyright (C)
* 2002. 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 java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import ca.uhn.hl7v2.ErrorCode;
import ca.uhn.hl7v2.HL7Exception;
import ca.uhn.hl7v2.HapiContext;
import ca.uhn.hl7v2.model.Composite;
import ca.uhn.hl7v2.model.DataTypeException;
import ca.uhn.hl7v2.model.GenericComposite;
import ca.uhn.hl7v2.model.GenericMessage;
import ca.uhn.hl7v2.model.GenericPrimitive;
import ca.uhn.hl7v2.model.Message;
import ca.uhn.hl7v2.model.Primitive;
import ca.uhn.hl7v2.model.Segment;
import ca.uhn.hl7v2.model.Type;
import ca.uhn.hl7v2.model.Varies;
import ca.uhn.hl7v2.util.Terser;
import ca.uhn.hl7v2.util.XMLUtils;
/**
* Parses and encodes HL7 messages in XML form, according to HL7's normative XML encoding
* specification. This is an abstract class that handles datatype and segment parsing/encoding, but
* not the parsing/encoding of entire messages. To use the XML parser, you should create a subclass
* for a certain message structure. This subclass must be able to identify the Segment objects that
* correspond to various Segment nodes in an XML document, and call the methods
* parse(Segment segment, ElementNode segmentNode) and
* encode(Segment segment, ElementNode segmentNode)
* as appropriate. XMLParser uses the Xerces parser, which must be installed in your
* classpath.
*
* @see ParserConfiguration for configuration options which may affect parser encoding and decoding behaviour
* @author Bryan Tripp, Shawn Bellina
*/
public abstract class XMLParser extends Parser {
private static final String ESCAPE_ATTRNAME = "V";
private static final String ESCAPE_NODENAME = "escape";
private static final Logger log = LoggerFactory.getLogger(XMLParser.class);
protected static final String NS = "urn:hl7-org:v2xml";
private static final Pattern NS_PATTERN = Pattern.compile("xmlns(.*)=\"" + NS + "\"");
private String textEncoding;
private boolean disableWhitespaceTrimming;
/** Constructor */
public XMLParser() {
super();
}
/**
*
* @param context the HAPI context
*/
public XMLParser(HapiContext context) {
super(context);
}
/**
* Constructor
*
* @param theFactory custom factory to use for model class lookup
*/
public XMLParser(ModelClassFactory theFactory) {
super(theFactory);
}
/**
* 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) {
return EncodingDetector.isXmlEncoded(message) ? getDefaultEncoding() : null;
}
/**
* @return the preferred encoding of this Parser
*/
public String getDefaultEncoding() {
return "XML";
}
/**
* Sets the keepAsOriginalNodes
*
* The nodes whose names match the keepAsOriginalNodes will be kept as original, meaning
* that no white space treaming will occur on them
*
* @param keepAsOriginalNodes of the nodes to be kept as original
* @deprecated Use {@link ParserConfiguration#setXmlDisableWhitespaceTrimmingOnNodeNames(Set)} instead. That method works exactly the same as this one but has been renamed for a more clear meaning.
*/
@Deprecated()
public void setKeepAsOriginalNodes(String[] keepAsOriginalNodes) {
getParserConfiguration().setXmlDisableWhitespaceTrimmingOnNodeNames(keepAsOriginalNodes);
}
/**
* Sets the keepAsOriginalNodes
*
* @deprecated Use {@link ParserConfiguration#getXmlDisableWhitespaceTrimmingOnNodeNames()} instead
*/
@Deprecated
public String[] getKeepAsOriginalNodes() {
return getParserConfiguration().getXmlDisableWhitespaceTrimmingOnNodeNames().toArray(new String[getParserConfiguration().getXmlDisableWhitespaceTrimmingOnNodeNames().size()]);
}
/**
*
* Creates and populates a Message object from an XML Document that contains an XML-encoded HL7
* message.
*
*
* The easiest way to implement this method for a particular message structure is as follows:
*
* - Create an instance of the Message type you are going to handle with your subclass of
* XMLParser
* - Go through the given Document and find the Elements that represent the top level of each
* message segment.
* - For each of these segments, call
*
parse(Segment segmentObject, Element segmentElement), providing the appropriate
* Segment from your Message object, and the corresponding Element.
*
* At the end of this process, your Message object should be populated with data from the XML
* Document.
*
*
* @param xmlMessage DOM message object to be parsed
* @param version HL7 version
* @throws HL7Exception if the message is not correctly formatted.
* @throws EncodingNotSupportedException if the message encoded is not supported by this parser.
*/
public abstract Message parseDocument(Document xmlMessage, String version) throws HL7Exception;
/**
*
* Parses a message string and returns the corresponding Message object. This method checks that
* the given message string is XML encoded, creates an XML Document object (using Xerces) from
* the given String, and calls the abstract method parse(Document XMLMessage)
*
*/
protected Message doParse(String message, String version) throws HL7Exception {
Message m;
// parse message string into a DOM document
Document doc;
doc = parseStringIntoDocument(message);
m = parseDocument(doc, version);
return m;
}
/**
* Parses a string containing an XML document into a Document object.
*
* Note that this method is synchronized currently, as the XML parser is not thread safe
*
* @throws HL7Exception
*/
protected synchronized Document parseStringIntoDocument(String message) throws HL7Exception {
try {
return XMLUtils.parse(message);
} catch (Exception e) {
throw new HL7Exception("Exception parsing XML", e);
}
}
/**
* 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 {
if (!encoding.equals("XML"))
throw new EncodingNotSupportedException("XMLParser supports only XML encoding");
return encode(source);
}
/**
* Formats a Message object into an HL7 message string using this parser's default encoding (XML
* encoding). This method calls the abstract method encodeDocument(...) in order to
* obtain XML Document object representation of the Message, then serializes it to a String.
*
* @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 {
if (source instanceof GenericMessage) {
throw new HL7Exception(
"Can't XML-encode a GenericMessage. Message must have a recognized structure.");
}
Document doc = encodeDocument(source);
// Element documentElement = doc.getDocumentElement();
// if (!documentElement.hasAttribute("xmlns"))
// documentElement.setAttribute("xmlns", "urn:hl7-org:v2xml");
try {
return XMLUtils.serialize(doc, getParserConfiguration().isPrettyPrintWhenEncodingXml());
} catch (Exception e) {
throw new HL7Exception("Exception serializing XML document to string", e);
}
}
/**
*
* Creates an XML Document that corresponds to the given Message object.
*
*
* If you are implementing this method, you should create an XML Document, and insert XML
* Elements into it that correspond to the groups and segments that belong to the message type
* that your subclass of XMLParser supports. Then, for each segment in the message, call the
* method encode(Segment segmentObject, Element segmentElement) using the Element
* for that segment and the corresponding Segment object from the given Message.
*
*
* @param source message
* @return the DOM document object of the encoded message
*/
public abstract Document encodeDocument(Message source) throws HL7Exception;
protected void assertNamespaceURI(String ns) throws HL7Exception {
if (!NS.equals(ns)) {
throw new HL7Exception("Namespace URI must be " + NS);
}
}
/**
* Populates the given Segment object with data from the given XML Element.
*
* @param segmentObject the segment to parse into
* @param segmentElement the DOM element to be parsed
* @throws HL7Exception if the XML Element does not have the correct name and structure for the
* given Segment, or if there is an error while setting individual field values.
*/
public void parse(Segment segmentObject, Element segmentElement) throws HL7Exception {
Set done = new HashSet();
NodeList all = segmentElement.getChildNodes();
for (int i = 0; i < all.getLength(); i++) {
String elementName = all.item(i).getNodeName();
if (all.item(i).getNodeType() == Node.ELEMENT_NODE && !done.contains(elementName)) {
assertNamespaceURI(all.item(i).getNamespaceURI());
done.add(elementName);
int index = elementName.indexOf('.');
if (index >= 0 && elementName.length() > index) { // properly formatted element
String fieldNumString = elementName.substring(index + 1);
int fieldNum = Integer.parseInt(fieldNumString);
parseReps(segmentObject, segmentElement, elementName, fieldNum);
} else {
log.debug("Child of segment {} doesn't look like a field {}",
segmentObject.getName(), elementName);
}
}
}
// set data type of OBX-5
if (segmentObject.getClass().getName().contains("OBX")) {
Varies.fixOBX5(segmentObject, getFactory(), getHapiContext().getParserConfiguration());
}
}
private void parseReps(Segment segmentObject, Element segmentElement, String fieldName,
int fieldNum) throws HL7Exception {
NodeList reps = segmentElement.getElementsByTagName(fieldName);
for (int i = 0; i < reps.getLength(); i++) {
parse(segmentObject.getField(fieldNum, i), (Element) reps.item(i));
}
}
/**
* Populates the given Element with data from the given Segment, by inserting Elements
* corresponding to the Segment's fields, their components, etc. Returns true if there is at
* least one data value in the segment.
*
* @param segmentObject the segment to be encoded
* @param segmentElement the DOM element to encode into
* @return true if there is at least one data value in the segment
* @throws HL7Exception if an erro occurred while encoding
*/
public boolean encode(Segment segmentObject, Element segmentElement) throws HL7Exception {
boolean hasValue = false;
int n = segmentObject.numFields();
for (int i = 1; i <= n; i++) {
String name = makeElementName(segmentObject, i);
Type[] reps = segmentObject.getField(i);
for (Type rep : reps) {
Element newNode = segmentElement.getOwnerDocument().createElement(name);
boolean componentHasValue = encode(rep, newNode);
if (componentHasValue) {
try {
segmentElement.appendChild(newNode);
} catch (DOMException e) {
throw new HL7Exception("DOMException encoding Segment: ", e);
}
hasValue = true;
}
}
}
return hasValue;
}
/**
* Populates the given Type object with data from the given XML Element.
*
* @param datatypeObject the type to parse into
* @param datatypeElement the DOM element to be parsed
* @throws DataTypeException if the data did not match the expected type rules
*/
public void parse(Type datatypeObject, Element datatypeElement) throws HL7Exception {
if (datatypeObject instanceof Varies) {
parseVaries((Varies) datatypeObject, datatypeElement);
} else if (datatypeObject instanceof Primitive) {
parsePrimitive((Primitive) datatypeObject, datatypeElement);
} else if (datatypeObject instanceof Composite) {
parseComposite((Composite) datatypeObject, datatypeElement);
}
}
/**
* Parses an XML element into a Varies by determining whether the element is primitive or
* composite, calling setData() on the Varies with a new generic primitive or composite as
* appropriate, and then calling parse again with the new Type object.
*/
private void parseVaries(Varies datatypeObject, Element datatypeElement)
throws HL7Exception {
// figure out what data type it holds
// short nodeType = datatypeElement.getFirstChild().getNodeType();
if (!hasChildElement(datatypeElement)) {
// it's a primitive
datatypeObject.setData(new GenericPrimitive(datatypeObject.getMessage()));
} else {
// it's a composite ... almost know what type, except that we don't have the version
// here
datatypeObject.setData(new GenericComposite(datatypeObject.getMessage()));
}
parse(datatypeObject.getData(), datatypeElement);
}
/** Returns true if any of the given element's children are (non-escape) elements */
private boolean hasChildElement(Element e) {
NodeList children = e.getChildNodes();
boolean hasElement = false;
int c = 0;
while (c < children.getLength() && !hasElement) {
if (children.item(c).getNodeType() == Node.ELEMENT_NODE
&& !ESCAPE_NODENAME.equals(children.item(c).getNodeName())) {
hasElement = true;
}
c++;
}
return hasElement;
}
/**
* Parses a primitive type by filling it with text child, if any. If the datatype element
* contains escape elements, resolve them properly.
*/
private void parsePrimitive(Primitive datatypeObject, Element datatypeElement)
throws HL7Exception {
NodeList children = datatypeElement.getChildNodes();
StringBuilder builder = new StringBuilder();
for (int c = 0; c < children.getLength(); c++) {
Node child = children.item(c);
try {
if (child.getNodeType() == Node.TEXT_NODE) {
String value = child.getNodeValue();
if (value != null && value.length() > 0) {
if (keepAsOriginal(child.getParentNode())) {
builder.append(value);
} else {
builder.append(removeWhitespace(value));
}
}
// Check for formatting elements
} else if (child.getNodeType() == Node.ELEMENT_NODE
&& ESCAPE_NODENAME.equals(child.getLocalName())) {
assertNamespaceURI(child.getNamespaceURI());
EncodingCharacters ec = EncodingCharacters.getInstance(datatypeObject
.getMessage());
Element elem = (Element) child;
String attr = elem.getAttribute(ESCAPE_ATTRNAME).trim();
if (attr != null && attr.length() > 0) {
builder.append(ec.getEscapeCharacter()).append(attr)
.append(ec.getEscapeCharacter());
}
}
} catch (Exception e) {
log.error("Error parsing primitive value from TEXT_NODE", e);
}
}
datatypeObject.setValue(builder.toString());
}
/**
* Checks if Node content should be kept as original (ie.: whitespaces won't be
* removed)
*
* @param node The target Node
* @return boolean true if whitespaces should not be removed from node content,
* false otherwise
*/
protected boolean keepAsOriginal(Node node) {
if (getParserConfiguration().isXmlDisableWhitespaceTrimmingOnAllNodes()) {
return true;
}
return (node.getNodeName() != null) && getParserConfiguration().getXmlDisableWhitespaceTrimmingOnNodeNames().contains(node.getNodeName());
}
/**
* Removes all unnecessary whitespace from the given String (intended to be used with Primitive
* values). This includes leading and trailing whitespace, and repeated space characters.
* Carriage returns, line feeds, and tabs are replaced with spaces.
*/
protected String removeWhitespace(String s) {
if (this.disableWhitespaceTrimming) {
return s;
}
s = s.replace('\r', ' ');
s = s.replace('\n', ' ');
s = s.replace('\t', ' ');
boolean repeatedSpacesExist = true;
while (repeatedSpacesExist) {
int loc = s.indexOf(" ");
if (loc < 0) {
repeatedSpacesExist = false;
} else {
StringBuilder buf = new StringBuilder();
buf.append(s.substring(0, loc));
buf.append(" ");
buf.append(s.substring(loc + 2));
s = buf.toString();
}
}
return s.trim();
}
/**
* Populates a Composite type by looping through it's children, finding corresponding Elements
* among the children of the given Element, and calling parse(Type, Element) for each.
*/
private void parseComposite(Composite datatypeObject, Element datatypeElement)
throws HL7Exception {
if (datatypeObject instanceof GenericComposite) { // elements won't be named
// GenericComposite.x
NodeList children = datatypeElement.getChildNodes();
int compNum = 0;
for (int i = 0; i < children.getLength(); i++) {
if (children.item(i).getNodeType() == Node.ELEMENT_NODE) {
Element nextElement = (Element) children.item(i);
assertNamespaceURI(nextElement.getNamespaceURI());
String localName = nextElement.getLocalName();
int dotIndex = localName.indexOf(".");
if (dotIndex > -1) {
compNum = Integer.parseInt(localName.substring(dotIndex + 1)) - 1;
} else {
log.debug(
"Datatype element {} doesn't have a valid numbered name, usgin default index of {}",
datatypeElement.getLocalName(), compNum);
}
Type nextComponent = datatypeObject.getComponent(compNum);
parse(nextComponent, nextElement);
compNum++;
}
}
} else {
Type[] children = datatypeObject.getComponents();
for (int i = 0; i < children.length; i++) {
NodeList matchingElements = datatypeElement.getElementsByTagNameNS(NS, makeElementName(
datatypeObject, i + 1));
if (matchingElements.getLength() > 0) {
parse(children[i], (Element) matchingElements.item(0));
}
}
int nextExtraCmpIndex = 0;
boolean foundExtraComponent;
do {
foundExtraComponent = false;
NodeList matchingElements = datatypeElement.getElementsByTagNameNS(NS, makeElementName(datatypeObject, children.length + nextExtraCmpIndex + 1));
if (matchingElements.getLength() > 0) {
parse(datatypeObject.getExtraComponents().getComponent(nextExtraCmpIndex), (Element) matchingElements.item(0));
foundExtraComponent = true;
}
nextExtraCmpIndex++;
} while (foundExtraComponent);
}
}
/** Returns the expected XML element name for the given child of the given Segment */
private String makeElementName(Segment s, int child) {
return s.getName() + "." + child;
}
/** Returns the expected XML element name for the given child of the given Composite */
private String makeElementName(Composite composite, int child) {
return composite.getName() + "." + child;
}
/**
* Populates the given Element with data from the given Type, by inserting Elements
* corresponding to the Type's components and values. Returns true if the given type contains a
* value (i.e. for Primitives, if getValue() doesn't return null, and for Composites, if at
* least one underlying Primitive doesn't return null).
*/
private boolean encode(Type datatypeObject, Element datatypeElement) throws DataTypeException {
boolean hasData = false;
if (datatypeObject instanceof Varies) {
hasData = encodeVaries((Varies) datatypeObject, datatypeElement);
} else if (datatypeObject instanceof Primitive) {
hasData = encodePrimitive((Primitive) datatypeObject, datatypeElement);
} else if (datatypeObject instanceof Composite) {
hasData = encodeComposite((Composite) datatypeObject, datatypeElement);
}
return hasData;
}
/**
* Encodes a Varies type by extracting it's data field and encoding that. Returns true if the
* data field (or one of its components) contains a value.
*/
private boolean encodeVaries(Varies datatypeObject, Element datatypeElement)
throws DataTypeException {
boolean hasData = false;
if (datatypeObject.getData() != null) {
hasData = encode(datatypeObject.getData(), datatypeElement);
}
return hasData;
}
/**
* Encodes a Primitive in XML by adding it's value as a child of the given Element. Detects
* escape character and creates proper elements in the DOM tree. Returns true if the
* given Primitive contains a value.
*/
private boolean encodePrimitive(Primitive datatypeObject, Element datatypeElement)
throws DataTypeException {
String value = datatypeObject.getValue();
boolean hasValue = (value != null && value.length() > 0);
if (hasValue) {
try {
EncodingCharacters ec = EncodingCharacters.getInstance(datatypeObject.getMessage());
char esc = ec.getEscapeCharacter();
int pos;
int oldpos = 0;
boolean escaping = false;
// Find next escape character
while ((pos = value.indexOf(esc, oldpos)) >= 0) {
// string until next escape character
String v = value.substring(oldpos, pos);
if (!escaping) {
// currently in "text mode", so create textnode from it
if (v.length() > 0)
datatypeElement.appendChild(datatypeElement.getOwnerDocument()
.createTextNode(v));
escaping = true;
} else {
if (v.startsWith(".") || "H".equals(v) || "N".equals(v)) {
// currently in "escape mode", so create escape element from it
Element escape = datatypeElement.getOwnerDocument().createElement(
ESCAPE_NODENAME);
escape.setAttribute(ESCAPE_ATTRNAME, v);
datatypeElement.appendChild(escape);
escaping = false;
} else {
// no proper escape sequence, assume text
datatypeElement.appendChild(datatypeElement.getOwnerDocument()
.createTextNode(esc + v));
}
}
oldpos = pos + 1;
}
// create text from the remainder
if (oldpos <= value.length()) {
StringBuilder sb = new StringBuilder();
// If we are in escaping mode, there appears no closing escape character,
// so we treat the string as text
if (escaping)
sb.append(esc);
sb.append(value.substring(oldpos));
datatypeElement.appendChild(datatypeElement.getOwnerDocument().createTextNode(
sb.toString()));
}
} catch (Exception e) {
throw new DataTypeException("Exception encoding Primitive: ", e);
}
}
return hasValue;
}
/**
* Encodes a Composite in XML by looping through it's components, creating new children for each
* of them (with the appropriate names) and populating them by calling encode(Type, Element)
* using these children. Returns true if at least one component contains a value.
*/
private boolean encodeComposite(Composite datatypeObject, Element datatypeElement)
throws DataTypeException {
Type[] components = datatypeObject.getComponents();
boolean hasValue = false;
for (int i = 0; i < components.length; i++) {
String name = makeElementName(datatypeObject, i + 1);
Element newNode = datatypeElement.getOwnerDocument().createElement(name);
boolean componentHasValue = encode(components[i], newNode);
if (componentHasValue) {
try {
datatypeElement.appendChild(newNode);
} catch (DOMException e) {
throw new DataTypeException("DOMException encoding Composite: ", e);
}
hasValue = true;
}
}
return hasValue;
}
/**
*
* 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 {
String version = getVersion(message);
Segment criticalData = Parser.makeControlMSH(version, getFactory());
Terser.set(criticalData, 1, 0, 1, 1, parseLeaf(message, "MSH.1", 0));
Terser.set(criticalData, 2, 0, 1, 1, parseLeaf(message, "MSH.2", 0));
Terser.set(criticalData, 10, 0, 1, 1, parseLeaf(message, "MSH.10", 0));
String procID = parseLeaf(message, "MSH.11", 0);
if (procID == null || procID.length() == 0) {
procID = parseLeaf(message, "PT.1", message.indexOf("MSH.11"));
// this field is a composite in later versions
}
Terser.set(criticalData, 11, 0, 1, 1, procID);
return criticalData;
}
/**
* 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). Trims whitespace from around the MSA-2 field.
*/
public String getAckID(String message) {
String ackID = null;
try {
ackID = parseLeaf(message, "msa.2", 0).trim();
} catch (HL7Exception e) { /* OK ... assume it isn't a response message */
}
return ackID;
}
public String getVersion(String message) throws HL7Exception {
String version = parseLeaf(message, "MSH.12", 0);
if (version == null || version.trim().length() == 0) {
version = parseLeaf(message, "VID.1", message.indexOf("MSH.12"));
}
return version;
}
/**
* Attempts to retrieve the value of a leaf tag without using DOM or SAX. This method searches
* the given message string for the given tag name, and returns everything after the given tag
* and before the start of the next tag. Whitespace is stripped. This is intended only for lead
* nodes, as the value is considered to end at the start of the next tag, regardless of whether
* it is the matching end tag or some other nested tag.
*
* @param message a string message in XML form
* @param tagName the name of the XML tag, e.g. "MSA.2"
* @param startAt the character location at which to start searching
* @throws HL7Exception if the tag can not be found
*/
protected static String parseLeaf(String message, String tagName, int startAt) throws HL7Exception {
// Workaround #176: XML may include explicit namespaces. It would be more stable to use some
// kind of pull parser for this method instead of manually digging for tags in the XML structure.
String prefix = "";
Matcher m = NS_PATTERN.matcher(message);
if (m.find()) {
String ns = m.group(1);
if (ns != null && ns.length() > 0) {
prefix = ns.substring(1) + ":";
}
}
int tagStart = message.indexOf("<" + prefix + tagName, startAt);
if (tagStart < 0)
tagStart = message.indexOf("<" + prefix + tagName.toUpperCase(), startAt);
int valStart = message.indexOf(">", tagStart) + 1;
int valEnd = message.indexOf("<", valStart);
String value;
if (tagStart >= 0 && valEnd >= valStart) {
value = message.substring(valStart, valEnd);
} else {
throw new HL7Exception("Couldn't find " + tagName + " in message beginning: "
+ message.substring(0, Math.min(150, message.length())),
ErrorCode.REQUIRED_FIELD_MISSING);
}
// Escape codes, as defined at http://hdf.ncsa.uiuc.edu/HDF5/XML/xml_escape_chars.htm
value = value.replaceAll(""", "\"");
value = value.replaceAll("'", "'");
value = value.replaceAll("&", "&");
value = value.replaceAll("<", "<");
value = value.replaceAll(">", ">");
return value;
}
/**
* Throws unsupported operation exception
*
* @throws UnsupportedOperationException
*/
@Override
public String doEncode(Segment structure, EncodingCharacters encodingCharacters)
throws HL7Exception {
throw new UnsupportedOperationException("Not supported yet.");
}
/**
* Throws unsupported operation exception
*
* @throws UnsupportedOperationException
*/
@Override
protected Message doParseForSpecificPackage(String theMessage, String theVersion,
String thePackageName) throws HL7Exception {
throw new UnsupportedOperationException("Not supported yet.");
}
/**
* Throws unsupported operation exception
*
* @throws UnsupportedOperationException
*/
@Override
public String doEncode(Type type, EncodingCharacters encodingCharacters) throws HL7Exception {
throw new UnsupportedOperationException("Not supported yet.");
}
/**
* Throws unsupported operation exception
*
* @throws UnsupportedOperationException
*/
@Override
public void parse(Type type, String string, EncodingCharacters encodingCharacters)
throws HL7Exception {
throw new UnsupportedOperationException("Not supported yet.");
}
/**
* Throws unsupported operation exception
*
* @throws UnsupportedOperationException
*/
@Override
public void parse(Segment segment, String string, EncodingCharacters encodingCharacters)
throws HL7Exception {
throw new UnsupportedOperationException("Not supported yet.");
}
/**
* Returns the text encoding to be used in generating new messages. Note that this affects
* encoding to string only, not parsing.
*
* @return text encoding
*/
public String getTextEncoding() {
return textEncoding;
}
/**
* Sets the text encoding to be used in generating new messages. Note that this affects encoding
* to string only, not parsing.
*
* @param textEncoding The encoding. Default is the platform default.
*/
public void setTextEncoding(String textEncoding) {
this.textEncoding = textEncoding;
}
}