1 |
522
|
berkley
|
/**
|
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 |
|
|
* '$Author$'
|
10 |
|
|
* '$Date$'
|
11 |
|
|
* '$Revision$'
|
12 |
|
|
*/
|
13 |
|
|
|
14 |
|
|
package edu.ucsb.nceas.metacat;
|
15 |
|
|
|
16 |
|
|
import java.sql.*;
|
17 |
|
|
import java.util.*;
|
18 |
|
|
import java.lang.Thread;
|
19 |
|
|
import java.io.*;
|
20 |
|
|
import java.net.*;
|
21 |
543
|
berkley
|
import java.text.*;
|
22 |
522
|
berkley
|
import org.xml.sax.AttributeList;
|
23 |
|
|
import org.xml.sax.ContentHandler;
|
24 |
|
|
import org.xml.sax.DTDHandler;
|
25 |
|
|
import org.xml.sax.EntityResolver;
|
26 |
|
|
import org.xml.sax.ErrorHandler;
|
27 |
|
|
import org.xml.sax.InputSource;
|
28 |
|
|
import org.xml.sax.XMLReader;
|
29 |
|
|
import org.xml.sax.SAXException;
|
30 |
|
|
import org.xml.sax.SAXParseException;
|
31 |
|
|
import org.xml.sax.helpers.XMLReaderFactory;
|
32 |
|
|
|
33 |
|
|
/**
|
34 |
|
|
* This class handles deltaT replication checking. Whenever this TimerTask
|
35 |
|
|
* is fired it checks each server in xml_replication for updates and updates
|
36 |
|
|
* the local db as needed.
|
37 |
|
|
*/
|
38 |
|
|
public class ReplicationHandler extends TimerTask
|
39 |
|
|
{
|
40 |
|
|
MetaCatUtil util = new MetaCatUtil();
|
41 |
|
|
Hashtable serverList = new Hashtable();
|
42 |
|
|
Connection conn;
|
43 |
|
|
PrintWriter out;
|
44 |
|
|
|
45 |
|
|
public ReplicationHandler(PrintWriter o)
|
46 |
|
|
{
|
47 |
|
|
this.out = o;
|
48 |
|
|
}
|
49 |
|
|
|
50 |
|
|
/**
|
51 |
|
|
* Method that implements TimerTask.run(). It runs whenever the timer is
|
52 |
|
|
* fired.
|
53 |
|
|
*/
|
54 |
|
|
public void run()
|
55 |
|
|
{
|
56 |
|
|
//find out the last_checked time of each server in the server list and
|
57 |
|
|
//send a query to each server to see if there are any documents in
|
58 |
|
|
//xml_documents with an update_date > last_checked
|
59 |
|
|
try
|
60 |
|
|
{
|
61 |
|
|
conn = util.openDBConnection();
|
62 |
|
|
serverList = buildServerList(conn);
|
63 |
|
|
update(serverList, conn);
|
64 |
533
|
berkley
|
conn.close();
|
65 |
522
|
berkley
|
}
|
66 |
|
|
catch (Exception e)
|
67 |
|
|
{
|
68 |
|
|
System.out.println("Error in replicationHandler.run(): " + e.getMessage());
|
69 |
|
|
}
|
70 |
|
|
}
|
71 |
|
|
|
72 |
|
|
/**
|
73 |
|
|
* Method to check each server in the servetList for updates
|
74 |
|
|
*/
|
75 |
|
|
private void update(Hashtable serverList, Connection conn)
|
76 |
|
|
{
|
77 |
|
|
/*
|
78 |
|
|
Pseudo-algorithm:
|
79 |
|
|
-build a list of servers that need to be checked
|
80 |
|
|
-check each server to see if any documents were modified after the
|
81 |
|
|
server's update_date
|
82 |
|
|
-if there are documents that need to be updated pull them here
|
83 |
|
|
and update the one currently in the database or add a new one
|
84 |
|
|
if it is not already here.
|
85 |
|
|
-update each servers' update_date to the current time
|
86 |
|
|
*/
|
87 |
|
|
PreparedStatement pstmt;
|
88 |
|
|
Enumeration keys;
|
89 |
|
|
int istreamInt;
|
90 |
|
|
char istreamChar;
|
91 |
|
|
StringBuffer serverResponse = new StringBuffer();
|
92 |
|
|
String server;
|
93 |
|
|
String update;
|
94 |
|
|
Vector responses = new Vector();
|
95 |
|
|
ReplMessageHandler message = new ReplMessageHandler();
|
96 |
533
|
berkley
|
Hashtable updateDocs = new Hashtable();
|
97 |
|
|
URL u;
|
98 |
|
|
InputStreamReader istream;
|
99 |
522
|
berkley
|
|
100 |
|
|
try
|
101 |
|
|
{
|
102 |
|
|
//build a list of servers with updated documents. Choose the newest
|
103 |
|
|
//one out of the list, update this server, update last_checked
|
104 |
|
|
|
105 |
|
|
keys = serverList.keys();
|
106 |
|
|
while(keys.hasMoreElements())
|
107 |
|
|
{ //update from one server at a time
|
108 |
|
|
server = (String)(keys.nextElement());
|
109 |
|
|
update = (String)(serverList.get(server));
|
110 |
|
|
//send the server a date and it will send back any docid that has
|
111 |
|
|
//been modified after that date
|
112 |
|
|
|
113 |
549
|
berkley
|
update = update.replace(' ', '+');
|
114 |
522
|
berkley
|
|
115 |
536
|
berkley
|
u = new URL("http://" + server + "?action=update&date=" + update);
|
116 |
533
|
berkley
|
istream = new InputStreamReader(u.openStream());
|
117 |
549
|
berkley
|
serverResponse = new StringBuffer();
|
118 |
522
|
berkley
|
while((istreamInt = istream.read()) != -1)
|
119 |
|
|
{
|
120 |
|
|
istreamChar = (char)istreamInt;
|
121 |
|
|
serverResponse.append(istreamChar);
|
122 |
|
|
}
|
123 |
|
|
responses.add(serverResponse.toString()); //list of updates
|
124 |
|
|
}
|
125 |
|
|
|
126 |
|
|
//initialize the parser
|
127 |
|
|
XMLReader parser = initParser(message);
|
128 |
537
|
berkley
|
//System.out.println("response: " + responses.toString());
|
129 |
|
|
//System.out.println("<--end response-->");
|
130 |
522
|
berkley
|
for(int i=0; i<responses.size(); i++)
|
131 |
|
|
{ //parse the xml and get the result
|
132 |
|
|
parser.parse(new InputSource(
|
133 |
|
|
new StringReader(
|
134 |
|
|
(String)(responses.elementAt(i)))));
|
135 |
554
|
berkley
|
Vector v = new Vector(message.getUpdatesVect());
|
136 |
|
|
Vector d = new Vector(message.getDeletesVect());
|
137 |
522
|
berkley
|
for(int j=0; j<v.size(); j++)
|
138 |
533
|
berkley
|
{ //go through each update vector and update or insert
|
139 |
|
|
//a new document
|
140 |
522
|
berkley
|
Vector w = new Vector((Vector)(v.elementAt(j)));
|
141 |
533
|
berkley
|
String docid = (String)w.elementAt(0);
|
142 |
|
|
String docServer = (String)w.elementAt(2);
|
143 |
|
|
|
144 |
|
|
//send a message to the server requesting each document
|
145 |
536
|
berkley
|
URL getDocURL = new URL("http://" + docServer +
|
146 |
|
|
"?action=getdocument&docid="+ docid);
|
147 |
533
|
berkley
|
InputStreamReader getDocIstream = new InputStreamReader(
|
148 |
549
|
berkley
|
getDocURL.openStream());
|
149 |
533
|
berkley
|
|
150 |
549
|
berkley
|
//the following while loop should not be needed. see the note
|
151 |
537
|
berkley
|
//below before the DocumentImpl.write() call.
|
152 |
|
|
serverResponse = new StringBuffer();
|
153 |
|
|
while((istreamInt = getDocIstream.read()) != -1)
|
154 |
|
|
{
|
155 |
|
|
istreamChar = (char)istreamInt;
|
156 |
|
|
serverResponse.append(istreamChar);
|
157 |
|
|
}
|
158 |
|
|
//System.out.println("<<<<<<document>>>>>");
|
159 |
|
|
//System.out.println(serverResponse.toString());
|
160 |
|
|
//System.out.println("<<<<<<end document>>>>>");
|
161 |
|
|
|
162 |
549
|
berkley
|
pstmt = conn.prepareStatement("select serverid from " +
|
163 |
|
|
"xml_replication where server " +
|
164 |
|
|
"like '" + docServer + "'");
|
165 |
|
|
pstmt.execute();
|
166 |
|
|
ResultSet rs = pstmt.getResultSet();
|
167 |
|
|
boolean tablehasrows = rs.next();
|
168 |
|
|
int serverCode = 0;
|
169 |
|
|
if(tablehasrows)
|
170 |
|
|
{
|
171 |
|
|
serverCode = rs.getInt(1);
|
172 |
551
|
berkley
|
//System.out.println("servercode: " + serverCode);
|
173 |
549
|
berkley
|
}
|
174 |
|
|
else
|
175 |
|
|
{
|
176 |
|
|
System.out.println("error: server not registered");
|
177 |
|
|
}
|
178 |
537
|
berkley
|
|
179 |
549
|
berkley
|
if(serverCode != 0)
|
180 |
|
|
{
|
181 |
|
|
//update the document into the DB
|
182 |
|
|
String action = getAction(docid);
|
183 |
|
|
//System.out.println("action: " + action + " docid: " + docid);
|
184 |
|
|
|
185 |
|
|
//note that getDocIstream is commented out below. This should
|
186 |
|
|
//work as a param to this method but it doesn'. I don't know why
|
187 |
|
|
//but putting a string reader there works but not an
|
188 |
|
|
//inputStreamReader.
|
189 |
|
|
String newDocid = DocumentImpl.write(conn,
|
190 |
537
|
berkley
|
new StringReader(serverResponse.toString())
|
191 |
|
|
/*getDocIstream*/,
|
192 |
|
|
action,
|
193 |
549
|
berkley
|
docid, null, null, serverCode);
|
194 |
|
|
System.out.println("newDocid: " + newDocid + " " + action + "ED");
|
195 |
|
|
}
|
196 |
522
|
berkley
|
}
|
197 |
554
|
berkley
|
|
198 |
|
|
for(int k=0; k<d.size(); k++)
|
199 |
|
|
{
|
200 |
|
|
Vector w = new Vector((Vector)d.elementAt(k));
|
201 |
|
|
String docid = (String)w.elementAt(0);
|
202 |
|
|
|
203 |
|
|
DocumentImpl.delete(conn, docid, null, null);
|
204 |
|
|
}
|
205 |
522
|
berkley
|
}
|
206 |
551
|
berkley
|
|
207 |
543
|
berkley
|
//update the last_update field for each server to the current date/time
|
208 |
|
|
SimpleDateFormat formatter = new SimpleDateFormat ("yy-MM-dd HH:mm:ss");
|
209 |
|
|
java.util.Date newDate = new java.util.Date(System.currentTimeMillis());
|
210 |
|
|
ParsePosition pos = new ParsePosition(0);
|
211 |
|
|
String dateString = formatter.format(newDate);
|
212 |
|
|
//System.out.println("dateString: " + dateString);
|
213 |
|
|
StringBuffer sql = new StringBuffer();
|
214 |
|
|
sql.append("update xml_replication set last_checked = to_date('");
|
215 |
|
|
sql.append(dateString).append("', 'YY-MM-DD HH24:MI:SS')");
|
216 |
545
|
berkley
|
//System.out.println("sql: " + sql.toString());
|
217 |
543
|
berkley
|
pstmt = conn.prepareStatement(sql.toString());
|
218 |
|
|
pstmt.executeUpdate();
|
219 |
|
|
//conn.commit();
|
220 |
|
|
System.out.println("last_checked updated: " + dateString);
|
221 |
551
|
berkley
|
|
222 |
522
|
berkley
|
}
|
223 |
|
|
catch(Exception e)
|
224 |
|
|
{
|
225 |
|
|
System.out.println("Error in replicationHandler.update(): " +
|
226 |
|
|
e.getMessage());
|
227 |
533
|
berkley
|
e.printStackTrace(System.out);
|
228 |
522
|
berkley
|
}
|
229 |
|
|
}
|
230 |
|
|
|
231 |
|
|
/**
|
232 |
533
|
berkley
|
* Checks to see if a document is already in the DB. Returns
|
233 |
|
|
* "UPDATE" if it is, "INSERT" if it isn't
|
234 |
|
|
*/
|
235 |
|
|
private static String getAction(String docid)
|
236 |
|
|
{
|
237 |
|
|
try
|
238 |
|
|
{
|
239 |
|
|
MetaCatUtil util = new MetaCatUtil();
|
240 |
|
|
StringBuffer sql = new StringBuffer();
|
241 |
|
|
sql.append("select docid from xml_documents where docid like '");
|
242 |
|
|
sql.append(docid).append("'");
|
243 |
|
|
Connection conn = util.openDBConnection();
|
244 |
|
|
PreparedStatement pstmt = conn.prepareStatement(sql.toString());
|
245 |
|
|
pstmt.execute();
|
246 |
|
|
ResultSet rs = pstmt.getResultSet();
|
247 |
|
|
|
248 |
|
|
if(rs.next())
|
249 |
|
|
{
|
250 |
|
|
conn.close();
|
251 |
|
|
return "UPDATE";
|
252 |
|
|
}
|
253 |
|
|
else
|
254 |
|
|
{
|
255 |
|
|
conn.close();
|
256 |
|
|
return "INSERT";
|
257 |
|
|
}
|
258 |
|
|
}
|
259 |
|
|
catch(Exception e)
|
260 |
|
|
{
|
261 |
|
|
System.out.println("error in replicationHandler.getAction: " +
|
262 |
|
|
e.getMessage());
|
263 |
|
|
}
|
264 |
|
|
return "";
|
265 |
|
|
}
|
266 |
|
|
|
267 |
|
|
/**
|
268 |
522
|
berkley
|
* Method to initialize the message parser
|
269 |
|
|
*/
|
270 |
|
|
private static XMLReader initParser(ReplMessageHandler rmh)
|
271 |
|
|
throws Exception
|
272 |
|
|
{
|
273 |
|
|
XMLReader parser = null;
|
274 |
|
|
|
275 |
|
|
try {
|
276 |
|
|
ContentHandler chandler = rmh;
|
277 |
|
|
|
278 |
|
|
// Get an instance of the parser
|
279 |
|
|
MetaCatUtil util = new MetaCatUtil();
|
280 |
|
|
String parserName = util.getOption("saxparser");
|
281 |
|
|
parser = XMLReaderFactory.createXMLReader(parserName);
|
282 |
|
|
|
283 |
|
|
// Turn off validation
|
284 |
|
|
parser.setFeature("http://xml.org/sax/features/validation", false);
|
285 |
|
|
|
286 |
|
|
parser.setContentHandler((ContentHandler)chandler);
|
287 |
|
|
parser.setErrorHandler((ErrorHandler)chandler);
|
288 |
|
|
|
289 |
|
|
} catch (Exception e) {
|
290 |
|
|
throw e;
|
291 |
|
|
}
|
292 |
|
|
|
293 |
|
|
return parser;
|
294 |
|
|
}
|
295 |
|
|
|
296 |
|
|
/**
|
297 |
|
|
* Method to query xml_replication and build a hashtable of each server
|
298 |
|
|
* and it's last update time.
|
299 |
|
|
* @param conn a connection to the database
|
300 |
|
|
*/
|
301 |
|
|
private Hashtable buildServerList(Connection conn)
|
302 |
|
|
{
|
303 |
|
|
Hashtable sl = new Hashtable();
|
304 |
|
|
PreparedStatement pstmt;
|
305 |
|
|
try
|
306 |
|
|
{
|
307 |
|
|
pstmt = conn.prepareStatement("select server, last_checked from " +
|
308 |
|
|
"xml_replication");
|
309 |
|
|
pstmt.execute();
|
310 |
|
|
ResultSet rs = pstmt.getResultSet();
|
311 |
|
|
boolean tableHasRows = rs.next();
|
312 |
|
|
while(tableHasRows)
|
313 |
|
|
{
|
314 |
549
|
berkley
|
String server = rs.getString(1);
|
315 |
|
|
String last_checked = rs.getString(2);
|
316 |
|
|
if(!server.equals("localhost"))
|
317 |
|
|
{
|
318 |
|
|
sl.put(server, last_checked);
|
319 |
|
|
}
|
320 |
522
|
berkley
|
tableHasRows = rs.next();
|
321 |
|
|
}
|
322 |
|
|
}
|
323 |
|
|
catch(Exception e)
|
324 |
|
|
{
|
325 |
|
|
System.out.println("error in replicationHandler.buildServerList(): " +
|
326 |
|
|
e.getMessage());
|
327 |
|
|
}
|
328 |
|
|
return sl;
|
329 |
|
|
}
|
330 |
|
|
}
|