/*
* Copyright (c) 2008-2014 MongoDB, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package example;
import com.mongodb.BasicDBObject;
import com.mongodb.Bytes;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import org.bson.types.BSONTimestamp;
public class ReadOplog {
public static void main(String[] args) throws Exception {
MongoClient mongoClient = new MongoClient();
DB local = mongoClient.getDB("local");
DBCollection oplog = local.getCollection("oplog.$main");
DBCursor lastCursor = oplog.find().sort(new BasicDBObject("$natural", -1)).limit(1);
if (!lastCursor.hasNext()) {
System.out.println("no oplog!");
return;
}
DBObject last = lastCursor.next();
BSONTimestamp ts = (BSONTimestamp) last.get("ts");
System.out.println("starting point: " + ts);
while (true) {
System.out.println("starting at ts: " + ts);
DBCursor cursor = oplog.find(new BasicDBObject("ts", new BasicDBObject("$gt", ts)));
cursor.addOption(Bytes.QUERYOPTION_TAILABLE);
cursor.addOption(Bytes.QUERYOPTION_AWAITDATA);
while (cursor.hasNext()) {
DBObject x = cursor.next();
ts = (BSONTimestamp) x.get("ts");
System.out.println("\t" + x);
}
Thread.sleep(1000);
}
}
}