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

Constructors

Constructor and Description
NodeComparator() Constructor

Method Summary

Modifier and Type	Method and Description
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

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

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.