rowset04.java

Java示例100

/**
 *  This sample exhibits the rollback functionality of OracleCachedRowSet.
 *  After all modification to the rowset restoreOriginal call is invoked to
 *  to restore the state of the rowset to it's original state.
 *  There are three more calls which can suppliment restoreOriginal viz.,
 *  (not depicted in the RowSet)
 *     - cancelRowInsert
 *     - cancelRowUpdate
 *     - cancelRowDelete
 *  which cancels the modifications to the present row.
 *
 *  Please use jdk1.2 or later version
 *
 *  useage: need to run a script "rowset.sql" to create a
 *          reservation table.
 *
 *  @author Ashok.Shivarudraiah
 */
import java.sql.SQLException;
import java.sql.Date;
import javax.sql.RowSet;
import oracle.jdbc.rowset.OracleCachedRowSet;

public class RowSet04 {
  public static void main (String []args)
  {
    String url = "java:oracle:oci8:@";
    try
    {
      OracleCachedRowSet crowset = new OracleCachedRowSet ();
      try
      {
        String url1 = System.getProperty ("JDBC_URL");
        if (url1 != null)
          url = url1;
      }catch (Exception ea) { }
      crowset.setUrl (url);
      crowset.setUsername ("hr");
      crowset.setPassword ("hr");
      crowset.setCommand ("SELECT seatno, tdate, name, class FROM reservation");
      crowset.execute ();

      System.out.println ("Displaying all the rows before modification");
      System.out.println ("Seat no  Travel Date  Name   Class");
      System.out.println ("-------  ------ ----  ----   -----");
      while (crowset.next ())
      {
        printRow (crowset);
      }// end of while (crowset.next ())

      System.out.println ("Write enabling the rowset");
      crowset.setReadOnly (false);

      System.out.println ("");
      crowset.beforeFirst ();
      {
        System.out.println ("Inserting a new passager with seat no 107");
        crowset.moveToInsertRow ();
        crowset.updateInt (1, 107);
        crowset.updateDate (2, new Date (975915381774L));
        crowset.updateString (3, "Pluto");
        crowset.updateString (4, "Business");
        crowset.insertRow ();
        System.out.println ("New row inserted");
      }

      System.out.println ("");
      crowset.beforeFirst ();
      if (crowset.absolute (2))
      {
        System.out.println ("Updating passenger's class at 102 from Economy to" 
          +" Business");
        crowset.updateString (4, "Business");
        crowset.updateRow ();
        System.out.println ("Row updated");
      }

      System.out.println ("");
      crowset.beforeFirst ();
      if (crowset.absolute (6))
      {
        System.out.println ("Deleting the passenger's entry at seatno: " 
          +crowset.getInt (1));
        crowset.deleteRow ();
        System.out.println ("Row deleted");
      }

      System.out.println ("");
      System.out.println ("Displaying all the rows after modification");
      System.out.println ("Seat no  Travel Date  Name   Class");
      System.out.println ("-------  ------ ----  ----   -----");
      crowset.beforeFirst ();
      while (crowset.next ())
      {
        printRow (crowset);
      }// end of while (crowset.next ())


      System.out.println ("");
      System.out.println ("Rolling back all the modifications made");
      crowset.restoreOriginal ();
      System.out.println ("Displaying all the rows restoring rowset to "
        +"its original state");
      System.out.println ("Seat no  Travel Date  Name   Class");
      System.out.println ("-------  ------ ----  ----   -----");
      crowset.beforeFirst ();
      while (crowset.next ())
      {
        printRow (crowset);
      }// end of while (crowset.next ())
      
      crowset.close ();
    }catch (SQLException ea)
    {
      ea.printStackTrace ();
    }
  }// end of main (String[])

  public static void printRow (RowSet rowset)
    throws SQLException
  {
    System.out.println (rowset.getInt (1) +"      " +rowset.getDate (2)
      +"   " +rowset.getString (3) +"  " +rowset.getString (4));
  }// end of printRow (RowSet)

}// end of class RowSet04