1 /**
   2  * AUTOHIT 2003
   3  * Copyright Erich P Gatejen (c) 1989,1997,2003,2004
   4  * 
   5  * This program is free software; you can redistribute it and/or modify 
   6  * it under the terms of the GNU General Public License as published by 
   7  * the Free Software Foundation; either version 2 of the License, or (at
   8  * your option) any later version.
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  * 
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Additional license information can be found in the documentation.
  19  * @author Erich P Gatejen
  20  */
  21 package autohit.call;
  22 
  23 import autohit.common.Constants;
  24 import autohit.universe.Universe;
  25 
  26 /**
  27  * CALL.  REMOVE_TABLE  Remove a table in persist.
  28  * <pre>
  29  * REQURIES: logger, core
  30  * IGNORES: uni
  31  * PARAMETERS (INPUT):
  32  * name= table name
  33  * </pre>
  34  * RETURNS: defined by the method, but will always be a String.
  35  *
  36  * @author Erich P. Gatejen
  37  * @version 1.0
  38  * <i>Version History</i>
  39  * <code>EPG - Initial - 30Jun03</code>
  40  */
  41 public class Call_REMOVE_TABLE extends Call {
  42 
  43 	/**
  44 	 * Implement this to handle load time initialization.  The 
  45 	 * four main fields will already be set--vmc, sc, log, and u.
  46 	 * You must implement this, but you don't have to do anything.
  47 	 * Remember that calls are cached per VM and reused as often
  48 	 * as possible.  There will be no thread-safety issues with the
  49 	 * VMCore or log, but the SystemContecxt and Universe may be shared.
  50 	 * @throws CallException
  51 	 */
  52 	public void load_chain() throws CallException {
  53 		// Nothing to do.
  54 	}
  55 
  56 	/**
  57 	 * Implement this to return the name of the CALL
  58 	 * @return name of the CALL
  59 	 */
  60 	public String name() {
  61 		return "REMOVE_TABLE";
  62 	}
  63 
  64 	/**
  65 	 * Execute it.
  66 	 * @return the result or null if there is no result
  67 	 */
  68 	public String call() throws CallException {
  69 
  70 		String name;
  71 
  72 		try {
  73 
  74 			// see if the parameter is passed
  75 			name = this.requiredString("name");
  76 
  77 			if (vmc.has(name)) {
  78 				vmc.free(name);
  79 				this.debug("Removed a table named=" + name);
  80 			} else {
  81 				this.debug(
  82 					"Table "
  83 						+ name
  84 						+ " not in persist.  Obviously, I cannot remove it.");
  85 			}
  86 
  87 		} catch (CallException ce) {
  88 			throw ce;
  89 		} catch (Exception e) {
  90 			throw new CallException(
  91 				this.format(
  92 					"Exception while removing table.  error=" + e.getMessage()),
  93 				CallException.CODE_CALL_ERROR,
  94 				e);
  95 		}
  96 		return Constants.EMPTY_LEFT;
  97 	}
  98 
  99 	/**
 100 	 * Execute using the passed universe, rather than the loaded.
 101 	 * @param uni a universe
 102 	 * @return the result or null if there is no result
 103 	 * @see autohit.universe.Universe
 104 	 */
 105 	public String call(Universe uni) throws CallException {
 106 		return this.call();
 107 	}
 108 }