/*
* Copyright 2001-2008 Geert Bevin (gbevin[remove] at uwyn dot com)
* Licensed under the Apache License, Version 2.0 (the "License")
* $Id: DbConnectionUser.java 3918 2008-04-14 17:35:35Z gbevin $
*/
package com.uwyn.rife.database;
/**
* By extending this class it's possible to provide the logic that should be
* executed by the {@link DbQueryManager#reserveConnection(DbConnectionUser)
* reserveConnection} method in the {@link DbQueryManager} class.
* <p>This class has both a default constructor and one that can take a data
* object. This can be handy when using it as an extending anonymous inner
* class when you need to use variables inside the inner class that are
* cumbersome to change to <code>final</code> in the enclosing class.
*
* @author JR Boyens (jboyens[remove] at uwyn dot com)
* @author Geert Bevin (gbevin[remove] at uwyn dot com)
* @version $Revision: 3918 $
* @see DbConnection
* @see DbQueryManager#reserveConnection(DbConnectionUser)
* @since 1.0
*/
import com.uwyn.rife.tools.ExceptionUtils;
import com.uwyn.rife.tools.exceptions.InnerClassException;
import java.util.logging.Logger;
public abstract class DbConnectionUser<ResultType, DataType> implements Cloneable
{
protected DataType mData = null;
/**
* Create a new DbConnectionUser.
*
* @since 1.0
*/
public DbConnectionUser()
{
}
/**
* Create a new DbConnectionUser with a data object.
*
* @param data a user data object to be stored locally
* @since 1.0
*/
public DbConnectionUser(DataType data)
{
mData = data;
}
/**
* Retrieve the data object that was provided to the constructor.
*
* @return the provided data object; or
* <p><code>null</code> if no data object was provided
* @since 1.0
*/
public DataType getData()
{
return mData;
}
/**
* Calling this method makes it possible to throw a checked exception
* from within this class.
* <p>To catch it you should surround the {@link
* DbQueryManager#reserveConnection(DbConnectionUser)
* reserveConnection} with a <code>try-catch</code> block that catches
* <code>InnerClassException</code>. The original exception is then
* available through <code>getCause()</code> and can for example be
* rethrown.
*
* @param exception the exception to be thrown
* @exception InnerClassException when a checked exception needs to be
* thrown from within this class and caught outside the caller.
* @since 1.0
*/
public void throwException(Exception exception)
throws InnerClassException
{
throw new InnerClassException(exception);
}
/**
* Should be implemented by all extending classes.
*
* @param connection the connection that should be used
* @since 1.0
*/
public abstract ResultType useConnection(DbConnection connection) throws InnerClassException;
/**
* Simply clones the instance with the default clone method since this
* class contains no member variables.
*
* @since 1.0
*/
public Object clone()
{
try
{
return super.clone();
}
catch (CloneNotSupportedException e)
{
// this should never happen
Logger.getLogger("com.uwyn.rife.database").severe(ExceptionUtils.getExceptionStackTrace(e));
return null;
}
}
}