1
|
/**
|
2
|
* '$RCSfile$'
|
3
|
* Purpose: A class to asyncronously do delta-T replication checking
|
4
|
* Copyright: 2000 Regents of the University of California and the
|
5
|
* National Center for Ecological Analysis and Synthesis
|
6
|
* Authors: Chad Berkley
|
7
|
* Release: @release@
|
8
|
*
|
9
|
* '$Author: jones $'
|
10
|
* '$Date: 2001-01-18 11:52:00 -0800 (Thu, 18 Jan 2001) $'
|
11
|
* '$Revision: 669 $'
|
12
|
*
|
13
|
* This program is free software; you can redistribute it and/or modify
|
14
|
* it under the terms of the GNU General Public License as published by
|
15
|
* the Free Software Foundation; either version 2 of the License, or
|
16
|
* (at your option) any later version.
|
17
|
*
|
18
|
* This program is distributed in the hope that it will be useful,
|
19
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
20
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
21
|
* GNU General Public License for more details.
|
22
|
*
|
23
|
* You should have received a copy of the GNU General Public License
|
24
|
* along with this program; if not, write to the Free Software
|
25
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
26
|
*/
|
27
|
|
28
|
package edu.ucsb.nceas.metacat;
|
29
|
|
30
|
import java.sql.*;
|
31
|
import java.util.*;
|
32
|
import java.lang.Thread;
|
33
|
import java.io.*;
|
34
|
import java.net.*;
|
35
|
import java.text.*;
|
36
|
import org.xml.sax.AttributeList;
|
37
|
import org.xml.sax.ContentHandler;
|
38
|
import org.xml.sax.DTDHandler;
|
39
|
import org.xml.sax.EntityResolver;
|
40
|
import org.xml.sax.ErrorHandler;
|
41
|
import org.xml.sax.InputSource;
|
42
|
import org.xml.sax.XMLReader;
|
43
|
import org.xml.sax.SAXException;
|
44
|
import org.xml.sax.SAXParseException;
|
45
|
import org.xml.sax.helpers.XMLReaderFactory;
|
46
|
import org.xml.sax.helpers.DefaultHandler;
|
47
|
|
48
|
|
49
|
|
50
|
/**
|
51
|
* This class handles deltaT replication checking. Whenever this TimerTask
|
52
|
* is fired it checks each server in xml_replication for updates and updates
|
53
|
* the local db as needed.
|
54
|
*/
|
55
|
public class ReplicationHandler extends TimerTask
|
56
|
{
|
57
|
int serverCheckCode = 1;
|
58
|
MetaCatUtil util = new MetaCatUtil();
|
59
|
Hashtable serverList = new Hashtable();
|
60
|
Connection conn;
|
61
|
PrintWriter out;
|
62
|
|
63
|
public ReplicationHandler(PrintWriter o)
|
64
|
{
|
65
|
this.out = o;
|
66
|
}
|
67
|
|
68
|
public ReplicationHandler(PrintWriter o, int serverCheckCode)
|
69
|
{
|
70
|
this.out = o;
|
71
|
this.serverCheckCode = serverCheckCode;
|
72
|
}
|
73
|
|
74
|
/**
|
75
|
* Method that implements TimerTask.run(). It runs whenever the timer is
|
76
|
* fired.
|
77
|
*/
|
78
|
public void run()
|
79
|
{
|
80
|
//find out the last_checked time of each server in the server list and
|
81
|
//send a query to each server to see if there are any documents in
|
82
|
//xml_documents with an update_date > last_checked
|
83
|
try
|
84
|
{
|
85
|
conn = util.openDBConnection();
|
86
|
serverList = buildServerList(conn);
|
87
|
update(serverList, conn);
|
88
|
updateCatalog(serverList, conn);
|
89
|
conn.close();
|
90
|
}
|
91
|
catch (Exception e)
|
92
|
{
|
93
|
System.out.println("Error in replicationHandler.run(): " + e.getMessage());
|
94
|
}
|
95
|
}
|
96
|
|
97
|
/**
|
98
|
* Method that uses revision taging for replication instead of update_date.
|
99
|
*/
|
100
|
private void update(Hashtable serverList, Connection conn)
|
101
|
{
|
102
|
/*
|
103
|
Pseudo-algorithm
|
104
|
- request a doc list from each server in xml_replication
|
105
|
- check the rev number of each of those documents agains the
|
106
|
documents in the local database
|
107
|
- pull any documents that have a lesser rev number on the local server
|
108
|
from the remote server
|
109
|
- delete any documents that still exist in the local xml_documents but
|
110
|
are in the deletedDocuments tag of the remote host response.
|
111
|
- update last_checked to keep track of the last time it was checked.
|
112
|
(this info is theoretically not needed using this system but probably
|
113
|
should be kept anyway)
|
114
|
*/
|
115
|
Enumeration keys;
|
116
|
String server;
|
117
|
String update;
|
118
|
ReplMessageHandler message = new ReplMessageHandler();
|
119
|
Vector responses = new Vector();
|
120
|
PreparedStatement pstmt = null;
|
121
|
ResultSet rs;
|
122
|
boolean tablehasrows;
|
123
|
boolean flag=false;
|
124
|
String action = new String();
|
125
|
XMLReader parser;
|
126
|
URL u;
|
127
|
|
128
|
try
|
129
|
{
|
130
|
MetaCatUtil.debugMessage("init parser");
|
131
|
parser = initParser(message);
|
132
|
keys = serverList.keys();
|
133
|
while(keys.hasMoreElements())
|
134
|
{
|
135
|
server = (String)(keys.nextElement());
|
136
|
MetacatReplication.replLog("full update started to: " + server);
|
137
|
u = new URL("http://" + server + "?action=update");
|
138
|
System.out.println("Sending Message: " + u.toString());
|
139
|
String result = MetacatReplication.getURLContent(u);
|
140
|
responses.add(result);
|
141
|
}
|
142
|
|
143
|
//System.out.println("responses: " + responses.toString());
|
144
|
|
145
|
for(int i=0; i<responses.size(); i++)
|
146
|
{ //check each server for updated files
|
147
|
//System.out.println("parsing responses");
|
148
|
parser.parse(new InputSource(
|
149
|
new StringReader(
|
150
|
(String)(responses.elementAt(i)))));
|
151
|
Vector v = new Vector(message.getUpdatesVect());
|
152
|
//System.out.println("v: " + v.toString());
|
153
|
Vector d = new Vector(message.getDeletesVect());
|
154
|
//check the revs in u to see if there are any newer ones than
|
155
|
//in the local DB.
|
156
|
for(int j=0; j<v.size(); j++)
|
157
|
{
|
158
|
Vector w = new Vector((Vector)(v.elementAt(j)));
|
159
|
//System.out.println("w: " + w.toString());
|
160
|
String docid = (String)w.elementAt(0);
|
161
|
//System.out.println("docid: " + docid);
|
162
|
int rev = Integer.parseInt((String)w.elementAt(1));
|
163
|
//System.out.println("rev: " + rev);
|
164
|
String docServer = (String)w.elementAt(2);
|
165
|
//System.out.println("docServer: " + docServer);
|
166
|
|
167
|
pstmt = conn.prepareStatement("select rev from xml_documents where "+
|
168
|
"docid like '" + docid + "'");
|
169
|
pstmt.execute();
|
170
|
rs = pstmt.getResultSet();
|
171
|
tablehasrows = rs.next();
|
172
|
if(tablehasrows)
|
173
|
{ //check the revs for an update because this document is in the
|
174
|
//local DB, it just might be out of date.
|
175
|
int localrev = rs.getInt(1);
|
176
|
if(localrev == rev)
|
177
|
{
|
178
|
flag = false;
|
179
|
}
|
180
|
else if(localrev < rev)
|
181
|
{//this document needs to be updated so send an read request
|
182
|
action = "UPDATE";
|
183
|
flag = true;
|
184
|
}
|
185
|
}
|
186
|
else
|
187
|
{ //insert this document as new because it is not in the local DB
|
188
|
action = "INSERT";
|
189
|
flag = true;
|
190
|
}
|
191
|
|
192
|
if(flag)
|
193
|
{ //if the document needs to be updated or inserted, this is executed
|
194
|
u = new URL("http://" + docServer + "?action=read&docid=" +
|
195
|
docid);
|
196
|
System.out.println("Sending message: " + u.toString());
|
197
|
String newxmldoc = MetacatReplication.getURLContent(u);
|
198
|
DocInfoHandler dih = new DocInfoHandler();
|
199
|
XMLReader docinfoParser = initParser(dih);
|
200
|
URL docinfoUrl = new URL("http://" + docServer +
|
201
|
"?action=getdocumentinfo&docid=" +
|
202
|
docid);
|
203
|
System.out.println("Sending message: " + docinfoUrl.toString());
|
204
|
String docInfoStr = MetacatReplication.getURLContent(docinfoUrl);
|
205
|
docinfoParser.parse(new InputSource(new StringReader(docInfoStr)));
|
206
|
Hashtable docinfoHash = dih.getDocInfo();
|
207
|
int serverCode = MetacatReplication.getServerCode(docServer);
|
208
|
System.out.println("updating doc: " + docid + " action: "+ action);
|
209
|
try
|
210
|
{
|
211
|
String newDocid = DocumentImpl.write(conn,
|
212
|
new StringReader(newxmldoc),
|
213
|
null,
|
214
|
action,
|
215
|
docid,
|
216
|
(String)docinfoHash.get("user_owner"),
|
217
|
(String)docinfoHash.get("user_owner"),
|
218
|
serverCode,
|
219
|
true);
|
220
|
MetacatReplication.replLog("wrote doc " + docid + " from " +
|
221
|
docServer);
|
222
|
System.out.println("wrote doc " + docid + " from " +
|
223
|
docServer);
|
224
|
}
|
225
|
catch(Exception e)
|
226
|
{
|
227
|
System.out.println("error writing document " + docid);
|
228
|
}
|
229
|
}
|
230
|
}
|
231
|
|
232
|
for(int k=0; k<d.size(); k++)
|
233
|
{ //delete the deleted documents;
|
234
|
Vector w = new Vector((Vector)d.elementAt(k));
|
235
|
String docid = (String)w.elementAt(0);
|
236
|
if(!alreadyDeleted(docid, conn))
|
237
|
{
|
238
|
DocumentImpl.delete(conn, docid, null, null);
|
239
|
System.out.println("Document " + docid + " deleted.");
|
240
|
MetacatReplication.replLog("doc " + docid + " deleted");
|
241
|
}
|
242
|
}
|
243
|
|
244
|
keys = serverList.keys();
|
245
|
while(keys.hasMoreElements())
|
246
|
{
|
247
|
server = (String)(keys.nextElement());
|
248
|
URL dateurl = new URL("http://" + server + "?action=gettime");
|
249
|
String datexml = MetacatReplication.getURLContent(dateurl);
|
250
|
String datestr = datexml.substring(11, datexml.indexOf('<', 11));
|
251
|
StringBuffer sql = new StringBuffer();
|
252
|
sql.append("update xml_replication set last_checked = to_date('");
|
253
|
sql.append(datestr).append("', 'YY-MM-DD HH24:MI:SS') where ");
|
254
|
sql.append("server like '").append(server).append("'");
|
255
|
//System.out.println("sql: " + sql.toString());
|
256
|
pstmt.close();
|
257
|
pstmt = conn.prepareStatement(sql.toString());
|
258
|
pstmt.executeUpdate();
|
259
|
//conn.commit();
|
260
|
System.out.println("last_checked updated to " + datestr + " on " +
|
261
|
server);
|
262
|
}
|
263
|
}
|
264
|
}
|
265
|
catch(Exception e)
|
266
|
{
|
267
|
System.out.println("error in update2: " + e.getMessage());
|
268
|
e.printStackTrace(System.out);
|
269
|
}
|
270
|
finally
|
271
|
{
|
272
|
try
|
273
|
{
|
274
|
pstmt.close();
|
275
|
}
|
276
|
catch(Exception ee) {}
|
277
|
}
|
278
|
}
|
279
|
|
280
|
/**
|
281
|
* updates xml_catalog with entries from other servers.
|
282
|
*/
|
283
|
private void updateCatalog(Hashtable serverList, Connection conn)
|
284
|
{
|
285
|
System.out.println("in updateCatalog");
|
286
|
try
|
287
|
{
|
288
|
String server;
|
289
|
Enumeration keys = serverList.keys();
|
290
|
while(keys.hasMoreElements())
|
291
|
{ //go through each server
|
292
|
server = (String)(keys.nextElement());
|
293
|
URL u = new URL("http://" + server + "?action=getcatalog");
|
294
|
System.out.println("sending message " + u.toString());
|
295
|
String catxml = MetacatReplication.getURLContent(u);
|
296
|
//System.out.println("catxml: " + catxml);
|
297
|
CatalogMessageHandler cmh = new CatalogMessageHandler();
|
298
|
XMLReader catparser = initParser(cmh);
|
299
|
catparser.parse(new InputSource(new StringReader(catxml)));
|
300
|
//parse the returned catalog xml and put it into a vector
|
301
|
Vector remoteCatalog = cmh.getCatalogVect();
|
302
|
|
303
|
String localcatxml = MetacatReplication.getCatalogXML();
|
304
|
//System.out.println("localcatxml: " + localcatxml);
|
305
|
cmh = new CatalogMessageHandler();
|
306
|
catparser = initParser(cmh);
|
307
|
catparser.parse(new InputSource(new StringReader(localcatxml)));
|
308
|
Vector localCatalog = cmh.getCatalogVect();
|
309
|
|
310
|
//now we have the catalog from the remote server and this local server
|
311
|
//we now need to compare the two and merge the differences.
|
312
|
//the comparison is base on the public_id fields which is the 4th
|
313
|
//entry in each row vector.
|
314
|
Vector publicId = new Vector();
|
315
|
for(int i=0; i<localCatalog.size(); i++)
|
316
|
{
|
317
|
Vector v = new Vector((Vector)localCatalog.elementAt(i));
|
318
|
//System.out.println("v1: " + v.toString());
|
319
|
publicId.add(new String((String)v.elementAt(3)));
|
320
|
//System.out.println("adding " + (String)v.elementAt(3));
|
321
|
}
|
322
|
|
323
|
for(int i=0; i<remoteCatalog.size(); i++)
|
324
|
{
|
325
|
Vector v = (Vector)remoteCatalog.elementAt(i);
|
326
|
//System.out.println("v2: " + v.toString());
|
327
|
//System.out.println("i: " + i);
|
328
|
//System.out.println("remoteCatalog.size(): " + remoteCatalog.size());
|
329
|
//System.out.println("publicID: " + publicId.toString());
|
330
|
//System.out.println("v.elementAt(3): " + (String)v.elementAt(3));
|
331
|
if(!publicId.contains(v.elementAt(3)))
|
332
|
{ //so we don't have this public id in our local table so we need to
|
333
|
//add it.
|
334
|
//System.out.println("in if");
|
335
|
StringBuffer sql = new StringBuffer();
|
336
|
sql.append("insert into xml_catalog (entry_type, source_doctype, ");
|
337
|
sql.append("target_doctype, public_id, system_id) values (?,?,?,");
|
338
|
sql.append("?,?)");
|
339
|
//System.out.println("sql: " + sql.toString());
|
340
|
PreparedStatement pstmt = conn.prepareStatement(sql.toString());
|
341
|
pstmt.setString(1, (String)v.elementAt(0));
|
342
|
pstmt.setString(2, (String)v.elementAt(1));
|
343
|
pstmt.setString(3, (String)v.elementAt(2));
|
344
|
pstmt.setString(4, (String)v.elementAt(3));
|
345
|
pstmt.setString(5, (String)v.elementAt(4));
|
346
|
pstmt.execute();
|
347
|
pstmt.close();
|
348
|
}
|
349
|
}
|
350
|
}
|
351
|
}
|
352
|
catch(Exception e)
|
353
|
{
|
354
|
System.out.println("error in updateCatalog: " + e.getMessage());
|
355
|
e.printStackTrace(System.out);
|
356
|
}
|
357
|
}
|
358
|
|
359
|
/**
|
360
|
* Method that returns true if docid has already been "deleted" from metacat.
|
361
|
* This method really implements a truth table for deleted documents
|
362
|
* The table is (a docid in one of the tables is represented by the X):
|
363
|
* xml_docs xml_revs deleted?
|
364
|
* ------------------------------------
|
365
|
* X X FALSE
|
366
|
* X _ FALSE
|
367
|
* _ X TRUE
|
368
|
* _ _ TRUE
|
369
|
*/
|
370
|
private static boolean alreadyDeleted(String docid, Connection conn)
|
371
|
{
|
372
|
try
|
373
|
{
|
374
|
boolean xml_docs = false;
|
375
|
boolean xml_revs = false;
|
376
|
|
377
|
StringBuffer sb = new StringBuffer();
|
378
|
sb.append("select docid from xml_revisions where docid like '");
|
379
|
sb.append(docid).append("'");
|
380
|
PreparedStatement pstmt = conn.prepareStatement(sb.toString());
|
381
|
pstmt.execute();
|
382
|
ResultSet rs = pstmt.getResultSet();
|
383
|
boolean tablehasrows = rs.next();
|
384
|
if(tablehasrows)
|
385
|
{
|
386
|
xml_revs = true;
|
387
|
}
|
388
|
|
389
|
sb = new StringBuffer();
|
390
|
sb.append("select docid from xml_documents where docid like '");
|
391
|
sb.append(docid).append("'");
|
392
|
pstmt.close();
|
393
|
pstmt = conn.prepareStatement(sb.toString());
|
394
|
pstmt.execute();
|
395
|
rs = pstmt.getResultSet();
|
396
|
tablehasrows = rs.next();
|
397
|
pstmt.close();
|
398
|
if(tablehasrows)
|
399
|
{
|
400
|
xml_docs = true;
|
401
|
}
|
402
|
|
403
|
if(xml_docs && xml_revs)
|
404
|
{
|
405
|
return false;
|
406
|
}
|
407
|
else if(xml_docs && !xml_revs)
|
408
|
{
|
409
|
return false;
|
410
|
}
|
411
|
else if(!xml_docs && xml_revs)
|
412
|
{
|
413
|
return true;
|
414
|
}
|
415
|
else if(!xml_docs && !xml_revs)
|
416
|
{
|
417
|
return true;
|
418
|
}
|
419
|
}
|
420
|
catch(Exception e)
|
421
|
{
|
422
|
System.out.println("error in alreadyDeleted: " + e.getMessage());
|
423
|
e.printStackTrace(System.out);
|
424
|
}
|
425
|
finally
|
426
|
{
|
427
|
|
428
|
}
|
429
|
return false;
|
430
|
}
|
431
|
|
432
|
/**
|
433
|
* Checks to see if a document is already in the DB. Returns
|
434
|
* "UPDATE" if it is, "INSERT" if it isn't
|
435
|
*/
|
436
|
private static String getAction(String docid)
|
437
|
{
|
438
|
try
|
439
|
{
|
440
|
MetaCatUtil util = new MetaCatUtil();
|
441
|
StringBuffer sql = new StringBuffer();
|
442
|
sql.append("select docid from xml_documents where docid like '");
|
443
|
sql.append(docid).append("'");
|
444
|
Connection conn = util.openDBConnection();
|
445
|
PreparedStatement pstmt = conn.prepareStatement(sql.toString());
|
446
|
pstmt.execute();
|
447
|
ResultSet rs = pstmt.getResultSet();
|
448
|
|
449
|
if(rs.next())
|
450
|
{
|
451
|
pstmt.close();
|
452
|
conn.close();
|
453
|
return "UPDATE";
|
454
|
}
|
455
|
else
|
456
|
{
|
457
|
pstmt.close();
|
458
|
conn.close();
|
459
|
return "INSERT";
|
460
|
}
|
461
|
}
|
462
|
catch(Exception e)
|
463
|
{
|
464
|
System.out.println("error in replicationHandler.getAction: " +
|
465
|
e.getMessage());
|
466
|
}
|
467
|
return "";
|
468
|
}
|
469
|
|
470
|
/**
|
471
|
* Method to query xml_replication and build a hashtable of each server
|
472
|
* and it's last update time.
|
473
|
* @param conn a connection to the database
|
474
|
*/
|
475
|
public static Hashtable buildServerList(Connection conn)
|
476
|
{
|
477
|
Hashtable sl = new Hashtable();
|
478
|
PreparedStatement pstmt;
|
479
|
try
|
480
|
{
|
481
|
pstmt = conn.prepareStatement("select server, last_checked, replicate " +
|
482
|
"from xml_replication");
|
483
|
pstmt.execute();
|
484
|
ResultSet rs = pstmt.getResultSet();
|
485
|
boolean tableHasRows = rs.next();
|
486
|
while(tableHasRows)
|
487
|
{
|
488
|
if(rs.getInt(3) == 1)
|
489
|
{//only put the server in the list if the replicate flag is true
|
490
|
String server = rs.getString(1);
|
491
|
String last_checked = rs.getString(2);
|
492
|
if(!server.equals("localhost"))
|
493
|
{
|
494
|
sl.put(server, last_checked);
|
495
|
}
|
496
|
}
|
497
|
tableHasRows = rs.next();
|
498
|
}
|
499
|
pstmt.close();
|
500
|
}
|
501
|
catch(Exception e)
|
502
|
{
|
503
|
System.out.println("error in replicationHandler.buildServerList(): " +
|
504
|
e.getMessage());
|
505
|
}
|
506
|
return sl;
|
507
|
}
|
508
|
|
509
|
/**
|
510
|
* Method to initialize the message parser
|
511
|
*/
|
512
|
public static XMLReader initParser(DefaultHandler dh)
|
513
|
throws Exception
|
514
|
{
|
515
|
XMLReader parser = null;
|
516
|
|
517
|
try {
|
518
|
ContentHandler chandler = dh;
|
519
|
|
520
|
// Get an instance of the parser
|
521
|
MetaCatUtil util = new MetaCatUtil();
|
522
|
String parserName = util.getOption("saxparser");
|
523
|
parser = XMLReaderFactory.createXMLReader(parserName);
|
524
|
|
525
|
// Turn off validation
|
526
|
parser.setFeature("http://xml.org/sax/features/validation", false);
|
527
|
|
528
|
parser.setContentHandler((ContentHandler)chandler);
|
529
|
parser.setErrorHandler((ErrorHandler)chandler);
|
530
|
|
531
|
} catch (Exception e) {
|
532
|
throw e;
|
533
|
}
|
534
|
|
535
|
return parser;
|
536
|
}
|
537
|
}
|