edu.ucsb.nceas.metacat
Class NodeComparator

java.lang.Object
  |
  +--edu.ucsb.nceas.metacat.NodeComparator
All Implemented Interfaces:
java.util.Comparator

public class NodeComparator
extends java.lang.Object
implements java.util.Comparator

A utility class that sorts two node records.

The order of the records determines how the XML document is printed from DocumentImpl.toXml(), so it is important that the sort order specified here results in a depth first traversal of the nodes in tree. Currently, the nodes are inserted into the database in this depth-forst order, so the nodeid identifiers are a good indicator of the proper sort order.

However, if we modify data loading semantics to allow document nodes to be rearranged, or otherwise change the nodeindex value, this current sort algorithm will fail to work.


Constructor Summary
NodeComparator()
          Constructor
 
Method Summary
 int compare(NodeRecord o1, NodeRecord o2)
          compare two NodeRecord objects to determine proper sort order.
 int compare(java.lang.Object o1, java.lang.Object o2)
          compare two objects to determine proper sort order -- delegates to the compare(NodeRecord, NodeRecord) method.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface java.util.Comparator
equals
 

Constructor Detail

NodeComparator

public NodeComparator()
Constructor

Method Detail

compare

public int compare(java.lang.Object o1,
                   java.lang.Object o2)
compare two objects to determine proper sort order -- delegates to the compare(NodeRecord, NodeRecord) method.

Specified by:
compare in interface java.util.Comparator

compare

public int compare(NodeRecord o1,
                   NodeRecord o2)
compare two NodeRecord objects to determine proper sort order. The node records are equal if their nodeid fields are equal. One is less than another if its parentnodeid is less, or if its parentnodeid is equal and its nodeindex is less. One is greater than another if its parentnodeid is greater, or if its parentnodeid is equal and its nodeindex is greater.



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