| 1 |
388
|
jones
|
/**
|
| 2 |
|
|
* '$RCSfile$'
|
| 3 |
|
|
* Purpose: A Class that sorts two NodeRecords
|
| 4 |
|
|
* Copyright: 2000 Regents of the University of California and the
|
| 5 |
|
|
* National Center for Ecological Analysis and Synthesis
|
| 6 |
|
|
* Authors: Matt Jones
|
| 7 |
|
|
* Release: @release@
|
| 8 |
|
|
*
|
| 9 |
|
|
* '$Author$'
|
| 10 |
|
|
* '$Date$'
|
| 11 |
|
|
* '$Revision$'
|
| 12 |
|
|
*/
|
| 13 |
|
|
|
| 14 |
|
|
package edu.ucsb.nceas.metacat;
|
| 15 |
|
|
|
| 16 |
|
|
import java.util.Comparator;
|
| 17 |
|
|
|
| 18 |
|
|
/**
|
| 19 |
429
|
jones
|
* A utility class that sorts two node records.
|
| 20 |
|
|
* <p>
|
| 21 |
|
|
* The order of the records
|
| 22 |
|
|
* determines how the XML document is printed from DocumentImpl.toXml(),
|
| 23 |
|
|
* so it is important that the sort order specified here results in a depth
|
| 24 |
|
|
* first traversal of the nodes in tree. Currently, the nodes are inserted
|
| 25 |
|
|
* into the database in this depth-forst order, so the nodeid identifiers
|
| 26 |
|
|
* are a good indicator of the proper sort order.
|
| 27 |
|
|
* <p>
|
| 28 |
|
|
* However, if we modify data loading semantics to allow document nodes to
|
| 29 |
|
|
* be rearranged, or otherwise change the nodeindex value, this current
|
| 30 |
|
|
* sort algorithm will fail to work.
|
| 31 |
388
|
jones
|
*/
|
| 32 |
|
|
public class NodeComparator implements Comparator {
|
| 33 |
|
|
|
| 34 |
|
|
static int LESS = -1;
|
| 35 |
|
|
static int EQUALS = 0;
|
| 36 |
|
|
static int GREATER = 1;
|
| 37 |
|
|
|
| 38 |
|
|
/**
|
| 39 |
|
|
* Constructor
|
| 40 |
|
|
*/
|
| 41 |
|
|
public NodeComparator() {
|
| 42 |
|
|
}
|
| 43 |
|
|
|
| 44 |
|
|
/**
|
| 45 |
389
|
jones
|
* compare two objects to determine proper sort order -- delegates to
|
| 46 |
|
|
* the compare(NodeRecord, NodeRecord) method.
|
| 47 |
388
|
jones
|
*/
|
| 48 |
|
|
public int compare(Object o1, Object o2) {
|
| 49 |
|
|
return compare((NodeRecord)o1, (NodeRecord)o2);
|
| 50 |
|
|
}
|
| 51 |
|
|
|
| 52 |
|
|
/**
|
| 53 |
|
|
* compare two NodeRecord objects to determine proper sort order. The
|
| 54 |
|
|
* node records are equal if their nodeid fields are equal. One is
|
| 55 |
|
|
* less than another if its parentnodeid is less, or if its parentnodeid
|
| 56 |
|
|
* is equal and its nodeindex is less. One is greater than another if
|
| 57 |
|
|
* its parentnodeid is greater, or if its parentnodeid is equal and
|
| 58 |
|
|
* its nodeindex is greater.
|
| 59 |
|
|
*/
|
| 60 |
389
|
jones
|
public int compare(NodeRecord o1, NodeRecord o2) {
|
| 61 |
388
|
jones
|
if (o1.nodeid == o2.nodeid) {
|
| 62 |
|
|
return EQUALS;
|
| 63 |
429
|
jones
|
} else if (o1.nodeid < o2.nodeid) {
|
| 64 |
|
|
return LESS;
|
| 65 |
|
|
} else if (o1.nodeid > o2.nodeid) {
|
| 66 |
|
|
return GREATER;
|
| 67 |
|
|
|
| 68 |
|
|
/* // This is old code that used to sort the records into breadth-first
|
| 69 |
|
|
// traversal order, based on the parentnodeid and the nodeindex.
|
| 70 |
|
|
//
|
| 71 |
|
|
if (o1.nodeid == o2.nodeid) {
|
| 72 |
|
|
return EQUALS;
|
| 73 |
388
|
jones
|
} else if (o1.parentnodeid < o2.parentnodeid) {
|
| 74 |
|
|
return LESS;
|
| 75 |
|
|
} else if (o1.parentnodeid > o2.parentnodeid) {
|
| 76 |
|
|
return GREATER;
|
| 77 |
|
|
} else if (o1.parentnodeid == o2.parentnodeid) {
|
| 78 |
|
|
if (o1.nodeindex < o2.nodeindex) {
|
| 79 |
|
|
return LESS;
|
| 80 |
|
|
} else if (o1.nodeindex > o2.nodeindex) {
|
| 81 |
|
|
return GREATER;
|
| 82 |
|
|
} else {
|
| 83 |
|
|
// this should never happen because (parentnodeid,nodeindex) is unique
|
| 84 |
|
|
return EQUALS;
|
| 85 |
|
|
}
|
| 86 |
429
|
jones
|
*/
|
| 87 |
388
|
jones
|
} else {
|
| 88 |
|
|
// this should never happen because parentnodeid is always <,>, or =
|
| 89 |
|
|
return EQUALS;
|
| 90 |
|
|
}
|
| 91 |
|
|
}
|
| 92 |
|
|
}
|