appexception.java

FuncPlotter is a combined Java application and applet for displaying two-dimensional plots of explic

/*====================================================================*\

AppException.java

Application exception class.

------------------------------------------------------------------------

This file is part of FuncPlotter, a combined Java application and applet
for plotting explicit functions in one variable.
Copyright 2005-2007 Andy Morgan-Richards.

FuncPlotter is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

This program 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
General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program.  If not, see <http://www.gnu.org/licenses/>.

\*====================================================================*/


// PACKAGE


package exception;

//----------------------------------------------------------------------


// APPLICATION EXCEPTION CLASS


public class AppException
    extends Exception
{

////////////////////////////////////////////////////////////////////////
//  Constants
////////////////////////////////////////////////////////////////////////

    public static final     String  SUBSTITUTION_PLACEHOLDER_PREFIX = "%";

    private static final    int MIN_SUBSTITUTION_INDEX  = 1;

    private static final    String  NO_ERROR_STR    = "No error";

////////////////////////////////////////////////////////////////////////
//  Member interfaces
////////////////////////////////////////////////////////////////////////


    // EXCEPTION IDENTIFIER INTERFACE


    public interface Id
    {

    ////////////////////////////////////////////////////////////////////
    //  Methods
    ////////////////////////////////////////////////////////////////////

        String getMessage( );

        //--------------------------------------------------------------

    }

    //==================================================================

////////////////////////////////////////////////////////////////////////
//  Member classes : non-inner classes
////////////////////////////////////////////////////////////////////////


    // ANONYMOUS IDENTIFIER CLASS


    protected static class AnonymousId
        implements Id
    {

    ////////////////////////////////////////////////////////////////////
    //  Constructors
    ////////////////////////////////////////////////////////////////////

        protected AnonymousId( String message )
        {
            this.message = message;
        }

        //--------------------------------------------------------------

    ////////////////////////////////////////////////////////////////////
    //  Instance methods : Id interface
    ////////////////////////////////////////////////////////////////////

        public String getMessage( )
        {
            return message;
        }

        //--------------------------------------------------------------

    ////////////////////////////////////////////////////////////////////
    //  Instance variables
    ////////////////////////////////////////////////////////////////////

        private String  message;

    }

    //==================================================================

////////////////////////////////////////////////////////////////////////
//  Constructors
////////////////////////////////////////////////////////////////////////

    public AppException( )
    {
    }

    //------------------------------------------------------------------

    public AppException( String messageStr )
    {
        this( new AnonymousId( messageStr ) );
    }

    //------------------------------------------------------------------

    public AppException( String   messageStr,
                         String[] substitutionStrs )
    {
        this( new AnonymousId( messageStr ), substitutionStrs );
    }

    //------------------------------------------------------------------

    public AppException( String    messageStr,
                         Throwable cause )
    {
        this( new AnonymousId( messageStr ), cause );
    }

    //------------------------------------------------------------------

    public AppException( String    messageStr,
                         Throwable cause,
                         String[]  substitutionStrs )
    {
        this( new AnonymousId( messageStr ), cause, substitutionStrs );
    }

    //------------------------------------------------------------------

    public AppException( Id id )
    {
        super( getString( id ) );
        this.id = id;
    }

    //------------------------------------------------------------------

    public AppException( Id       id,
                         String[] substitutionStrs )
    {
        this( id );
        setSubstitutionStrings( substitutionStrs );
    }

    //------------------------------------------------------------------

    public AppException( Id        id,
                         Throwable cause )
    {
        super( getString( id ), cause );
        this.id = id;
    }

    //------------------------------------------------------------------

    public AppException( Id        id,
                         Throwable cause,
                         String[]  substitutionStrs )
    {
        this( id, cause );
        setSubstitutionStrings( substitutionStrs );
    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Class methods
////////////////////////////////////////////////////////////////////////

    public static String getString( Id id )
    {
        return ( (id == null) ? NO_ERROR_STR : id.getMessage( ) );
    }

    //------------------------------------------------------------------

    protected static String createString( String    message,
                                          String[]  substitutionStrs,
                                          Throwable cause )
    {

        // Append the detail message

        StringBuilder buffer = new StringBuilder( );
        if ( message != null )
            buffer.append( message );

        // Insert any substitution strings

        if ( substitutionStrs != null )
        {
            int index = 0;
            while ( index < buffer.length( ) )
            {
                index = buffer.indexOf( SUBSTITUTION_PLACEHOLDER_PREFIX, index );
                if ( index < 0 )
                    index = buffer.length( );
                else
                    ++index;
                int startIndex = index;
                while ( index < buffer.length( ) )
                {
                    char ch = buffer.charAt( index );
                    if ( (ch < '0') || (ch > '9') )
                        break;
                    ++index;
                }
                if ( index > startIndex )
                {
                    int substIndex = Integer.parseInt( buffer.substring( startIndex, index ) ) -
                                                                                    MIN_SUBSTITUTION_INDEX;
                    if ( (substIndex >= 0) && (substIndex < substitutionStrs.length) )
                    {
                        String substStr = substitutionStrs[substIndex];
                        if ( substStr == null )
                            substStr = new String( );
                        --startIndex;
                        buffer.replace( startIndex, index, substStr );
                        index = startIndex + substStr.length( );
                    }
                }
            }
        }

        // Append the detail message of the cause

        if ( cause != null )
        {
            String str = cause.getMessage( );
            if ( str == null )
                str = cause.toString( );
            buffer.append( "\n[" );
            buffer.append( str );
            buffer.append( ']' );
        }

        return buffer.toString( );

    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance methods : overriding methods
////////////////////////////////////////////////////////////////////////

    public String toString( )
    {
        return createString( getMessage( ), substitutionStrs, getCause( ) );
    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance methods
////////////////////////////////////////////////////////////////////////

    public Id getId( )
    {
        return id;
    }

    //------------------------------------------------------------------

    public String[] getSubstitutionStrings( )
    {
        return substitutionStrs;
    }

    //------------------------------------------------------------------

    public void clearSubstitutionStrings( )
    {
        substitutionStrs = null;
    }

    //------------------------------------------------------------------

    public void setSubstitutionStrings( String[] strs )
    {
        substitutionStrs = strs;
    }

    //------------------------------------------------------------------

    public void setSubstitutionString( String str )
    {
        substitutionStrs = new String[1];
        substitutionStrs[0] = str;
    }

    //------------------------------------------------------------------

    public void setSubstitutionDecVal( int value )
    {
        setSubstitutionString( Integer.toString( value ) );
    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance variables
////////////////////////////////////////////////////////////////////////

    private Id          id;
    private String[]    substitutionStrs;

}

//----------------------------------------------------------------------