executestatement.java

Town是一个100% 纯Java API

package com.workingdogs.town;

import java.io.*;
import java.sql.*;

/*
Town, a Java JDBC abstraction layer
Copyright (C) 1999  Serge Knystautas, Jon Stevens

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA  02111-1307, USA.
*/
/**
 * A very simple class to execute SQL that does not return data.  While we recommend using
 * the TableDataSet object for inserts, deletes, and often for updates, we recognize there will
 * be some SQL such as stored procedures or batch inserts, deletes, and updates that should
 * be handled inside the database for performance reason.  During object construction, this object
 will automatically execute the SQL statement provided.
<P>
Here is an example to delete all records from table_name

  <PRE>
  new ExecuteStatement (connectionString, "DELETE * from table_name");
  </PRE>

<P>
The object automatically interacts with the database connection pool to use a connection
and then return it to the pool.
 * <br>
 *
 * @author Serge Knystautas <a href="mailto:[e-mail]">[e-mail]</a>
 * @version 1.0
 */

public class ExecuteStatement extends DBConnection
{
    String sqlstatement = null;
    /**
      * Executes a given statement on the given connection.  This object immediately becomes useless
      * after construction... it's meant as a one time execution.
      * @param connString java.lang.String
      * @param tableName java.lang.String
      * @exception com.lokitech.town.DataSetException The exception description.
      * @exception com.lokitech.town.ConnectionException The exception description.
      */
    public ExecuteStatement(String driver, String connString,
            String sqlstatement) throws DataSetException,
    ConnectionException
    {
        super(driver, connString);

        this.sqlstatement = sqlstatement;
        execute ();
        close ();
    }
    /**
      * Executes a given statement on the given connection.  This object immediately becomes useless
      * after construction... it's meant as a one time execution.
      * @param connString java.lang.String
      * @param tableName java.lang.String
      * @exception com.lokitech.town.DataSetException The exception description.
      * @exception com.lokitech.town.ConnectionException The exception description.
      */
    public ExecuteStatement(String driver, String connString,
            String username, String password,
            String sqlstatement) throws DataSetException,
    ConnectionException
    {
        super(driver, connString, username, password);

        this.sqlstatement = sqlstatement;
        execute ();
        close ();
    }
    /**
      * Executes the SQL statement
      */
    private void execute () throws ConnectionException
    {
        try
        {
            if (stmt == null)
            {
                stmt = connection().createStatement();
                stmt.execute (sqlstatement);
            }
        }
        catch (SQLException e)
        {
            if (stmt != null)
            {
                try
                {
                    stmt.close();
                }
                catch (SQLException sqle)
                {
                    throw new ConnectionException (sqle);
                }
            }
            //throw new SQLException (e.getMessage());
            throw new ConnectionException (e);
        }

    }
}