org.firebirdsql.gds.GDS g = org.firebirdsql.gds.GDSObjectFactory.createJavaGDSImpl();

import org.firebirdsql.gds.*; //DatabaseParameterBuffer;
import org.firebirdsql.jca.*; //FBConnectionRequestInfo;
// Code was modified by Roman Rokytskyy to show that Firebird JCA-JDBC driver
// does not introduce additional complexity in normal driver usage scenario.
//
// An example of using a JDBC 2 Standard Extension DataSource.
// The DataSource facility provides an alternative to the JDBC DriverManager,
// essentially duplicating all of the driver managerТs useful functionality.
// Although, both mechanisms may be used by the same application if desired,
// JavaSoft encourages developers to regard the DriverManager as a legacy
// feature of the JDBC API.
// Applications should use the DataSource API whenever possible.
// A JDBC implementation that is accessed via the DataSource API is not
// automatically registered with the DriverManager.
// The DriverManager, Driver, and DriverPropertyInfo interfaces
// may be deprecated in the future.

public final class DataSource2
{
  static public void main (String args[]) throws Exception
  {
    // Create an Firebird data source manually;

    org.firebirdsql.pool.FBWrappingDataSource ds =
        new org.firebirdsql.pool.FBWrappingDataSource();

    // Set the standard properties
    ds.setDatabase ("localhost/3253:C:/1INSTALL/FIREBIRD/FB25SNAP/examples/empbuild/EMPLOYEE.FDB");
    //ds.setBuffersNumber(4096);

    //ds.setDescription ("An example database of employees");

        /*
         * Following properties were not deleted in order to show differences
         * between InterClient 2.01 data source implementation and Firebird one.
         */

    //dataSource.setDataSourceName ("Employee");
    //dataSource.setPortNumber (3060);
    //dataSource.setNetworkProtocol ("jdbc:interbase:");
    //dataSource.setRoleName (null);

    // Set the non-standard properties
    //dataSource.setCharSet (interbase.interclient.CharacterEncodings.NONE);
    //dataSource.setSuggestedCachePages (0);
    //dataSource.setSweepOnConnect (false);

    // this some kind of equivalent to dataSource.setNetworkProtocol(String)
    // possible values are "type4", "type2" and "embedded".
    ds.setType("TYPE4");
    // SQL Role can be set like this:
    // dataSource.setRoleName("USER");
    // Character encoding for the connection is set to NONE
    ds.setEncoding("WIN1251"); // ISO8859_1");
    //ds.setBuffersNumber(8192);

    // other non-standard properties do not have setters
    // you can pass any DPB parameter
    //
    // dataSource.setNonStandardProperty("isc_dpb_sweep", null);
    // dataSource.setNonStandardProperty("isc_dpb_num_buffers", "75");
   ds.setNonStandardProperty("isc_dpb_num_buffers", "8192");


    // Connect to the Firebird DataSource
    try {

      java.sql.Connection c = ds.getConnection ("sysdba", "masterke");
      System.out.println(ds.getDatabase());
      DatabaseParameterBuffer dpb = ds.getDatabaseParameterBuffer();

      System.out.println("num_buffers="+ds.getNonStandardProperty("isc_dpb_num_buffers"));

      System.out.println("ForcedWrites="+DatabaseParameterBuffer.FORCE_WRITE);

      System.out.println("DummyPacketinterval="+DatabaseParameterBuffer.DUMMY_PACKET_INTERVAL);

      //System.out.println("SET_PAGE_BUFFERS="+DatabaseParameterBuffer.SET_PAGE_BUFFERS);
      // why zero ?? --> System.out.println("BUFFER_LENGTH="+dpb.getArgumentAsInt(DatabaseParameterBuffer.BUFFER_LENGTH) );

      //System.out.println("NUM_BUFFERS="+dpb.getArgumentAsInt(DatabaseParameterBuffer.NUM_BUFFERS));
      // why zero ?? --> System.out.println("PAGE_SIZE="+dpb.getArgumentAsInt(DatabaseParameterBuffer.PAGE_SIZE));


      org.firebirdsql.gds.GDS gdso = org.firebirdsql.gds.GDSObjectFactory.createJavaGDSImpl();
      // Factory method to create a new IscDbHandle instance specific to the implementation of this interface.
      IscDbHandle dh =  gdso.createIscDbHandle();
      System.out.println("dh="+dh);  // OK, like this: dh=org.firebirdsql.gds.impl.wire.isc_db_handle_impl@13e8d89  

       // why NPE ?? --> System.out.println(dh.getVersion()); 
       // why zero ?? --> System.out.println(dh.getDialect());
      // why NPE ?? --> System.out.println(dh.getVersion()); 

// здесь тоже вылезет NPE, но я вообще не понял, какой тут надо буфер указывать и какого размера должен быть 
// byte[]-массив dbstat - в левой части от вызова
//      byte[] dbstat = {0,0,0,0};
//      byte[] items = {  ISCConstants.isc_info_reads,
//                        ISCConstants.isc_info_writes,
//                        ISCConstants.isc_info_fetches,
//                        ISCConstants.isc_info_marks};
//      dbstat=gdso.iscDatabaseInfo(dh, items, 32760);

      //  http://www.firebirdsql.org/file/documentation/drivers_documentation/java/2.2.3/docs/org/firebirdsql/gds/ISCConstants.html 
      // byte[]	iscDatabaseInfo(IscDbHandle dbHandle, byte[] items, int bufferLength)

      // At this point, there is no implicit driver instance
      // registered with the driver manager!
      System.out.println ("got connection");
      c.close ();
    }
    catch (java.sql.SQLException e) {
                e.printStackTrace();
      System.out.println ("sql exception: " + e.getMessage ());
    }
  }
}

// compile: javac -cp .;jaybird-full-2.2.3.jar FbGatherStatistics.java
// run:     java -cp .;jaybird-full-2.2.3.jar FbGatherStatistics 1>FbGatherStatistics.log 2>FbGatherStatistics.err

import org.firebirdsql.gds.*;
public final class FbGatherStatistics
{
  private static final String DB_URL="localhost/3253:C:/1INSTALL/FIREBIRD/FB25SNAP/T0.FDB ";
  private static final String DB_USER="sysdba";
  private static final String DB_PSWD="masterke";
  static public void main (String args[]) throws Exception
  {
    try {

      org.firebirdsql.gds.GDS gdso = org.firebirdsql.gds.GDSObjectFactory.createJavaGDSImpl();
      // Factory method to create a new IscDbHandle instance specific to the implementation of this interface.
      IscDbHandle dh =  gdso.createIscDbHandle();

      DatabaseParameterBuffer dpb = gdso.createDatabaseParameterBuffer();
      dpb.addArgument(DatabaseParameterBuffer.USER, DB_USER);
      dpb.addArgument(DatabaseParameterBuffer.PASSWORD, DB_PSWD);
      System.out.println("dpb="+dpb);

      gdso.iscAttachDatabase(DB_URL, dh, dpb);

      byte[] dbstat;
      byte[] items = {  ISCConstants.isc_info_insert_count,
                        ISCConstants.isc_info_reads,
                        ISCConstants.isc_info_writes,
                        ISCConstants.isc_info_fetches,
                        ISCConstants.isc_info_marks,
                        ISCConstants.isc_info_end,
                    };
      dbstat=gdso.iscDatabaseInfo(dh, items, 32760);
      System.out.println(dbstat.length);
      for(int i=0;i<dbstat.length;i++) {
          byte item=dbstat[i];
          switch(item) {
            case ISCConstants.isc_info_insert_count:
                System.out.println("insert_count="+dbstat[i]); break;
            case ISCConstants.isc_info_reads:
                System.out.println("reads_count="+dbstat[i]); break;
            case ISCConstants.isc_info_writes:
                System.out.println("writes_count="+dbstat[i]); break;
            case ISCConstants.isc_info_fetches:
                System.out.println("fetches_count="+dbstat[i]); break;
            case ISCConstants.isc_info_marks:
                System.out.println("marks_count="+dbstat[i]); break;
            default:
                break;
          }
      }


      //for(int i=0;i<=items.length;i++) System.out.println(dbstat[i]);
      //for(int i=0;i<=items.length;i++) System.out.println(dbstat[items[i]]);
//      System.out.println(ISCConstants.isc_info_insert_count);
//      int i=0;
//      System.out.println("ISCConstants.isc_info_end="+ISCConstants.isc_info_end);
//      while( dbstat[i] != ISCConstants.isc_info_end ) {
//          System.out.println(dbstat[i]);
//          i++;
//      }

      // http://www.firebirdsql.org/file/documentation/drivers_documentation/java/2.2.3/docs/org/firebirdsql/gds/ISCConstants.html
      // byte[]	iscDatabaseInfo(IscDbHandle dbHandle, byte[] items, int bufferLength)

      System.out.println ("got connection");
      gdso.iscDetachDatabase(dh);
    }
    catch (Exception e) {
        e.printStackTrace();
    }
  }
}

dpb=org.firebirdsql.gds.impl.wire.DatabaseParameterBufferImp@a956ac07
32
insert_count=25
reads_count=5
writes_count=6
fetches_count=7
reads_count=5
marks_count=8
got connection

CSMIRROR (Client)       Mon Dec 09 16:32:33 2013
        "C:\1Install\FIREBIRD_2_5\bin\fbserver.exe": terminated abnormally (4294967295)

java -cp .;jaybird-full-2.2.4.jar FbGatherStatistics | mtee FbGatherStatistics.log

17:58:29.896 trying to attach. . .
17:58:30.021 attached to 192.168.0.220/3330:idx_test
17:58:30.021 trying to gather db statistics. . .
17:58:30.021 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             24115
		fetches:             24705
		marks  :              9749
17:58:35.021 trying to gather db statistics. . .
17:58:35.021 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             24900
		fetches:              1569
		marks  :             30928
. . .
17:58:55.037 trying to gather db statistics. . .
17:58:55.037 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             28782
		fetches:              3529
		marks  :             14562
. . .
17:59:15.037 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             32245
		fetches:              1741
		marks  :             54524
17:59:20.052 trying to gather db statistics. . .
17:59:20.052 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             33430
		fetches:             14672
		marks  :             31130
. . .
18:01:10.068 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             52948
		fetches:             24564
		marks  :             31217
18:01:15.068 trying to gather db statistics. . .
18:01:15.068 statistics gathered, dbstat[] length=33
		reads  :               171
		writes :             54139
		fetches:             61381
		marks  :              7841

$ grep "^[^#;]" /opt/fb30/firebird.conf|sort
AuthClient = Legacy_Auth,Srp,Win_Sspi
AuthServer = Legacy_Auth,Srp
BugcheckAbort = 1
DefaultDbCachePages = 512K
ExternalFileAccess = Restrict /var/db/fb30
FileSystemCacheThreshold = 1024K
RemoteServicePort = 3330
UserManager = Legacy_UserManager
WireCrypt = Disabled