简单总结了一下我目前知道的方法。

package test;
import java.sql.Connection;
  import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;


/**
   * 三种获得自动生成主键的方法。

 * 

 * @author javadou.com 

 *
   */

public class TestGetPK { 

  public static void main(String[] args) throws Exception {
      Class.forName("com.gbase.jdbc.Driver");

    String url = "jdbc:gbase://localhost/mytest";

    Connection con = DriverManager.getConnection(url, "root", "111111"); 

    System.out.println(getPK1(con));
      System.out.println(getPK2(con));

    System.out.println(getPK3(con));

  } 

  /**
     * 使用JDBC 3.0提供的 getGeneratedKeys。推荐使用

   * 

   * @param con

   * @return

   * @throws Exception

   */

  public static long getPK1(Connection con) throws Exception {

    Statement stmt = con.createStatement();

    stmt.executeUpdate("INSERT INTO t_type (name) values ('Can I Get the Auto Increment Field?')",

        Statement.RETURN_GENERATED_KEYS); 

    int autoIncKeyFromApi = -1;
      ResultSet rs = stmt.getGeneratedKeys();

    if (rs.next()) {

      autoIncKeyFromApi = rs.getInt(1);

    }

    return autoIncKeyFromApi;

  } 

  /**
     * 使用数据库自己的特殊SQL.

   * 

   * @param con

   * @return

   * @throws Exception

   */

  public static long getPK2(Connection con) throws Exception {

    Statement stmt = con.createStatement();

    stmt.executeUpdate("INSERT INTO t_type (name) values ('Can I Get the Auto Increment Field?')",

        Statement.RETURN_GENERATED_KEYS); 

    int autoIncKeyFromFunc = -1;
      ResultSet rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");

    if (rs.next()) {

      autoIncKeyFromFunc = rs.getInt(1);

    }

    return autoIncKeyFromFunc;

  } 

  /**
     * 使用可更新的结果集。

   * 

   * @param con

   * @return

   * @throws Exception

   */

  public static long getPK3(Connection con) throws Exception {

    Statement stmt = con.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,

        java.sql.ResultSet.CONCUR_UPDATABLE);

    ResultSet rs = stmt.executeQuery("SELECT * FROM t_Type");

    rs.moveToInsertRow();

    rs.updateString("name", "AUTO INCREMENT here?");

    rs.insertRow();

    rs.last();

    int autoIncKeyFromRS = rs.getInt("id");

    return autoIncKeyFromRS;

  }

}