MongoDB in PHP, Java, and C - MongoDB in Action - page 269

D.2.2 Connections

Creating a single-node connection is easy as long as you remember to wrap the call in
a try block:

try {
Mongo conn = new Mongo("localhost", 27017);
} catch (Exception e) {
throw new RuntimeException(e);

}
To c o n n e c t t o a r e p l i c a s e t , f i r s t b u i l d a l i s t o f ServerAddress objects. Then pass that
list to the Mongo constructor:

List servers = new ArrayList();
servers.add( new ServerAddress( "localhost" , 30000 ) );
servers.add( new ServerAddress( "localhost" , 30001 ) );

try {
Mongo replConn = new Mongo( servers );
} catch (Exception e) {
throw new RuntimeException(e);
The Java driver includes flexible support for write concern. You can specify a different
write concern on the Mongo , DB , and DBCollection objects, as well as on any of
DBCollection 's write methods. Here we specify a global write concern on the connec-
tion using the WriteConcern configuration class:

WriteConcern w = new WriteConcern( 1, 2000 );
conn.setWriteConcern( w );

D.2.3 Sample program

This Java program is a direct translation of the previous PHP program, and it should
be self-explanatory:

import com.mongodb.Mongo;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.BasicDBObject;
import com.mongodb.DBObject;
import com.mongodb.DBCursor;
import com.mongodb.WriteConcern;
import java.util.Date;

public class Sample {

public static void main(String[] args) {

Mongo conn;
try {
conn = new Mongo("localhost", 27017);
} catch (Exception e) {
throw new RuntimeException(e);

}

WriteConcern w = new WriteConcern( 1, 2000 );