/** * Licensed under the Artistic License; you may not use this file * except in compliance with the License. * You may obtain a copy of the License at * *      http://displaytag.sourceforge.net/license.html * * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */package org.displaytag.exception;import javax.servlet.jsp.JspTagException;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.displaytag.Messages;/** * Base exception: extendes JspTagException providing logging and exception nesting functionalities. * @author Fabrizio Giustina * @version $Revision: 1081 $ ($Author: fgiust $) */public abstract class BaseNestableJspTagException extends JspTagException{    /**     * Class where the exception has been generated.     */    private final Class sourceClass;    /**     * previous exception.     */    private Throwable nestedException;    /**     * Instantiate a new BaseNestableJspTagException.     * @param source Class where the exception is generated     * @param message message     */    public BaseNestableJspTagException(Class source, String message)    {        super(message);        this.sourceClass = source;        // log exception        Log log = LogFactory.getLog(source);        // choose appropriate logging method        if (getSeverity() == SeverityEnum.DEBUG)        {            log.debug(toString());        }        else if (getSeverity() == SeverityEnum.INFO)        {            log.info(toString());        }        else if (getSeverity() == SeverityEnum.WARN)        {            log.warn(toString());        }        else        {            // error - default            log.error(toString());        }    }    /**     * Instantiate a new BaseNestableJspTagException.     * @param source Class where the exception is generated     * @param message message     * @param cause previous Exception     */    public BaseNestableJspTagException(Class source, String message, Throwable cause)    {        super(message);        this.sourceClass = source;        this.nestedException = cause;        // log exception        Log log = LogFactory.getLog(source);        // choose appropriate logging method        if (getSeverity() == SeverityEnum.DEBUG)        {            log.debug(toString(), cause);        }        else if (getSeverity() == SeverityEnum.INFO)        {            log.info(toString(), cause);        }        else if (getSeverity() == SeverityEnum.WARN)        {            log.warn(toString(), cause);        }        else        {            // error - default            log.error(toString(), cause);        }    }    /**     * returns the previous exception.     * @return Throwable previous exception     */    public Throwable getCause()    {        return this.nestedException;    }    /**     * basic toString. Returns the message plus the previous exception (if a previous exception exists).     * @return String     */    public String toString()    {        String className = this.sourceClass.getName();        className = className.substring(className.lastIndexOf(".")); //$NON-NLS-1$        if (this.nestedException == null)        {            return Messages.getString("NestableException.msg", //$NON-NLS-1$                new Object[]{className, getMessage()});        }        return Messages.getString("NestableException.msgcause", //$NON-NLS-1$            new Object[]{className, getMessage(), this.nestedException.getMessage()});    }    /**     * subclasses need to define the getSeverity method to provide correct severity for logging.     * @return SeverityEnum exception severity     * @see org.displaytag.exception.SeverityEnum     */    public abstract SeverityEnum getSeverity();}