Package ca.uhn.hl7v2.parser

Class DefaultModelClassFactory

java.lang.Object
ca.uhn.hl7v2.parser.AbstractModelClassFactory
ca.uhn.hl7v2.parser.DefaultModelClassFactory
All Implemented Interfaces:
ModelClassFactory, Serializable
Direct Known Subclasses:
CanonicalModelClassFactory
public class DefaultModelClassFactory extends AbstractModelClassFactory
Default implementation of ModelClassFactory. See packageList() for configuration instructions.
Version:
$Revision: 1.9 $ updated on $Date: 2010-08-05 17:51:16 $ by $Author: jamesagnew $
Author:
Bryan Tripp
See Also:

  • Constructor Details

  • Method Details

    • getMessageClass

      public Class<? extends Message> getMessageClass(String theName, String theVersion, boolean isExplicit) throws HL7Exception

      Attempts to return the message class corresponding to the given name, by searching through default and user-defined (as per packageList()) packages. Returns GenericMessage if the class is not found.

      It is important to note that there can only be one implementation of a particular message structure (i.e. one class with the message structure name, regardless of its package) among the packages defined as per the packageList() method. If there are duplicates (e.g. two ADT_A01 classes) the first one in the search order will always be used. However, this restriction only applies to message classes, not (normally) segment classes, etc. This is because classes representing parts of a message are referenced explicitly in the code for the message class, rather than being looked up (using findMessageClass() ) based on the String value of MSH-9. The exception is that Segments may have to be looked up by name when they appear in unexpected locations (e.g. by local extension) -- see findSegmentClass().

      Note: the current implementation will be slow if there are multiple user- defined packages, because the JVM will try to load a number of non-existent classes every parse. This should be changed so that specific classes, rather than packages, are registered by name.

      Parameters:
      theName - name of the desired structure in the form XXX_YYY
      theVersion - HL7 version (e.g. "2.3")
      isExplicit - true if the structure was specified explicitly in MSH-9-3, false if it was inferred from MSH-9-1 and MSH-9-2. If false, a lookup may be performed to find an alternate structure corresponding to that message type and event.
      Returns:
      corresponding message subclass if found; GenericMessage otherwise
      Throws:
      HL7Exception - if the version if not recognized or an appropriate class can not be found

    • getGroupClass

      public Class<? extends Group> getGroupClass(String theName, String theVersion) throws HL7Exception
      Parameters:
      theName - name of group
      theVersion - HL7 version
      Returns:
      a class that implements the specified group
      Throws:
      HL7Exception - if the version if not recognized or an appropriate class can not be found
      See Also:

    • getSegmentClass

      public Class<? extends Segment> getSegmentClass(String theName, String theVersion) throws HL7Exception
      Parameters:
      theName - name of segment
      theVersion - HL7 version
      Returns:
      a class that implements the specified segment
      Throws:
      HL7Exception - if the version if not recognized or an appropriate class can not be found
      See Also:

    • getTypeClass

      public Class<? extends Type> getTypeClass(String theName, String theVersion) throws HL7Exception
      Parameters:
      theName - name of type
      theVersion - HL7 version
      Returns:
      a class that implements the specified type
      Throws:
      HL7Exception - if the version if not recognized or an appropriate class can not be found
      See Also:

    • getMessageClassInASpecificPackage

      public Class<? extends Message> getMessageClassInASpecificPackage(String theName, String theVersion, boolean isExplicit, String packageName) throws HL7Exception
      Retrieves and instantiates a message class by looking in a specific java package for the message type.
      Parameters:
      theName - The message structure type (e.g. "ADT_A01")
      theVersion - The HL7 version (e.g. "2.3.1")
      isExplicit - If false, the message structure is looked up using Parser.getMessageStructureForEvent(String, String) and converted to the appropriate structure type. For example, "ADT_A04" would be converted to "ADT_A01" because the A04 trigger uses the A01 message structure according to HL7.
      packageName - The package name to use. Note that if the message type can't be found in this package, HAPI will return the standard type returned by getMessageClass(String, String, boolean)
      Returns:
      message class
      Throws:
      HL7Exception
      Since:
      1.3

    • getVersionPackagePath

      public static String getVersionPackagePath(String ver) throws HL7Exception
      Returns the path to the base package for model elements of the given version - e.g. "ca/uhn/hl7v2/model/v24/". This package should have the packages datatype, segment, group, and message under it. The path ends in with a slash.
      Parameters:
      ver - HL7 version
      Returns:
      package path of the version
      Throws:
      HL7Exception - if the HL7 version is unknown

    • getVersionPackageName

      public static String getVersionPackageName(String ver) throws HL7Exception
      Returns the package name for model elements of the given version - e.g. "ca.uhn.hl7v2.model.v24.". This method is identical to getVersionPackagePath(...) except that path separators are replaced with dots.
      Parameters:
      ver - HL7 version
      Returns:
      package name of the version
      Throws:
      HL7Exception - if the HL7 version is unknown

    • packageList

      public static String[] packageList(String version)

      Lists all the packages (user-definable) where classes for standard and custom messages may be found. Each package has subpackages called "message", "group", "segment", and "datatype" in which classes for these message elements can be found.

      At a minimum, this method returns the standard package for the given version. For example, for version 2.4, the package list contains ca.uhn.hl7v2.model.v24. In addition, user-defined packages may be specified for custom messages.

      If you define custom message classes, and want Parsers to be able to find them, you must register them as follows (otherwise you will get an exception when the corresponding messages are parsed). For each HL7 version you want to support, you must put a text file on your classpath, under the folder /custom_packages, named after the version. For example, for version 2.4, you might put the file "custom_packages/2.4" in your application JAR. Each line in the file should name a package to search for message classes of that version. For example, if you work at foo.org, you might create a v2.4 message structure called "ZFO" and define it in the class org.foo.hl7.custom.message.ZFO. In order for parsers to find this message class, you would need to enter the following line in custom_packages/2.4:

      org.foo.hl7.custom

      Packages are searched in the order specified. The standard package for a given version is searched last, allowing you to override the default implementation. Please note that if you create custom classes for messages, segments, etc., their names must correspond exactly to their names in the message text. For example, if you subclass the QBP segment in order to add your own fields, your subclass must also be called QBP. although it will obviously be in a different package. To make sure your class is used instead of the default implementation, put your package in the package list. User-defined packages are searched first, so yours will be found first and used.

      It is important to note that there can only be one implementation of a particular message structure (i.e. one class with the message structure name, regardless of its package) among the packages defined as per the packageList() method. If there are duplicates (e.g. two ADT_A01 classes) the first one in the search order will always be used. However, this restriction only applies to message classes, not segment classes, etc. This is because classes representing parts of a message are referenced explicitly in the code for the message class, rather than being looked up (using findMessageClass() ) based on the String value of MSH-9.

      Parameters:
      version - HL7 version
      Returns:
      array of package prefix names

    • reloadPackages

      public static void reloadPackages()
      Reloads the packages. Note that this should not be performed after and messages have been parsed or otherwise generated, as undetermined behaviour may result.

    • getHighestKnownVersion

      public static String getHighestKnownVersion()
      Returns a string containing the highest known version of HL7 known to HAPI (i.e. "2.6"). Note that this is determined by checking which structure JARs are available on the classpath, so if this release of HAPI supports version 2.6, but only the hapi-structures-v23.jar is available on the classpath, "2.3" will be returned
      Returns:
      the most recent HL7 version known to HAPI

    • getMessageStructureForEvent

      public String getMessageStructureForEvent(String name, Version version) throws HL7Exception
      Returns the event structure. If nothing could be found, the event name is returned
      Specified by:
      getMessageStructureForEvent in interface ModelClassFactory
      Overrides:
      getMessageStructureForEvent in class AbstractModelClassFactory
      Parameters:
      name - event name
      version - HL7 version
      Returns:
      message structure name for the eventName and version or null if none could be found
      Throws:
      HL7Exception - if the version is unknown or the message structure list is inaccessible
      See Also: