Package ca.uhn.hl7v2.preparser

Class DatumPath

java.lang.Object
ca.uhn.hl7v2.preparser.DatumPath
All Implemented Interfaces:
Cloneable
public class DatumPath extends Object implements Cloneable
An object of this class represents a variable-size path for identifying the location of a datum within an HL7 message, which we can use for maintaining parser state and for generating a suitable string key (in the ZYX[a]-b[c]-d-e style) for a piece of data in the message (see toString()). The elements are: segmentID / segmentRepIdx / fieldIdx / fieldRepIdx / compIdx / subcompIdx ("rep" means "repetition") segmentID is a String, the rest are Integers. It is variable-size path-style in that if it has a size of 1, the one element will be the segmentID; if it has a size of two, element 0 will be the segmentID and element 1 will be the segmentRepIdx, etc. This class can't represent a fieldIdx without having segmentID / segmentRepIdx, etc. etc. possible sizes: 0 to 6 inclusive As toString() simply converts this's integer values to strings (1 => "1"), and since for some reason the ZYX[a]-b[c]-d-e style counts b, d, e starting from 1 and a, c from 0 -- it is intended that one store the numeric values in this class starting from 1 for fieldIdx (element 2), compIdx (4) and subcompIdx (5), and from 0 for segmentRepIdx (1) and fieldRepIdx (3). default values provided by setSize() and by toString() do this.

  • Field Details

  • Constructor Details

  • Method Details

    • equals

      public boolean equals(Object otherObject)
      Overrides:
      equals in class Object

    • startsWith

      public boolean startsWith(DatumPath prefix)
      Works like String.startsWith: returns true iff prefix.size() <= this.size() AND if, for 0 <= i < prefix.size(), this.get(i).equals(prefix.get(i))

    • copy

      public void copy(DatumPath other)
      like a copy constructor without the constructor

    • set

      public void set(int idx, Object new_value)
      set() sets an element of the path. idx must be in [0, size()). else => IndexOutOfBoundsException. (new_value == null) => NullPointerException new_value must be either a String or an Integer depending on what part of the path you're setting: (idx == 0) => String (idx >= 1) => Integer If new_value can't be cast to the appropriate type, a ClassCastException is thrown before new_value is stored. Of course, on success, this will discard it's reference that used to be at position idx.

    • get

      public Object get(int idx)
      get() returns an element, which will be either a String or an Integer. ((idx == 0) => String (idx >= 1) => Integer ((idx < 0) || (idx >= size())) => IndexOutOfBoundsException We will attempt to cast the gotten object to the appropriate type before returning it as an Object. That way, if there's an object of the wrong type in the wrong place in here (that got past set() somehow), then a ClassCastException will be thrown even if the caller of this function doesn't try to cast it. (consider System.out.println("val: " + path.get(n)) nothing would barf it this get() wasn't vigilant.)

    • size

      public int size()

    • toString

      public String toString()
      toString() outputs the path (from segmentID onward) in the ZYX[a]-b[c]-d-e style (TODO: give it a name), suitable for a key in a map of message datum paths to values. Integer values are converted to strings directly (1 => "1") so when you constructed this you should have started counting from 1 for everything but the "repeat" fields, if you truly want the ZYX[a]-b[c]-d-e style. If toString() is called when this has a size in [1, 6) (=> missing numeric elments), then we act as though the elements in [size(), 6) are 0 or 1 as appropriate for each element. We don't provide a default for the element 0 (the String element): will throw an IndexOutOfBoundsException if (size() == 1). eg. a (new DatumPath()).add(new String("ZYX")).add(2).add(6).toString() would yield "ZYX[2]-6[0]-1-1"
      Overrides:
      toString in class Object

    • add

      public DatumPath add(Object newValue)
      add() grows this by 1, inserting newValue at the end. newValue must be a String or an Integer depending on the index where it will be inserted, as noted at DatumPath.set(). returns this. (newValue == null) => NullPointerException

    • add

      public DatumPath add(int new_value)
      Like add(String). convenient wrapper for add(Object), when the object to be added must be an Integer anyway (size() > 0 on entry). For the user, it turns path.add(new Integer(i)).add(new Integer(j)).add(new Integer(k)) into path.add(i).add(j).add(k), that's all. size() == 0 on entry throws a ClassCastException (which it is, kindof), otherwise calls add(new Integer(new_value)).

    • add

      public DatumPath add(String new_value)
      convenience! Like add(int), but the other way around.

    • setSize

      public DatumPath setSize(int newSize)
      setSize(): resize. If this will grow the object, then we put default values into the new elements: "" into the String element, Integer(1) into the elements 2, 4, and 5, and Integer(0) into elements 1 and 3. returns this.

    • clear

      public DatumPath clear()
      setSize(0). returns this.

    • clone

      public Object clone()
      Overrides:
      clone in class Object

    • numbersLessThan

      public boolean numbersLessThan(DatumPath other)

    • main

      public static void main(String[] args)