multex
Class Exc

java.lang.Object
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  +--java.lang.Throwable
        |
        +--java.lang.Exception
              |
              +--multex.Exc

Direct Known Subclasses:

Copy.StartedExc

public abstract class Exc

extends java.lang.Exception

implements MultexException

Problem-related exception with named parameters and internationalizable message text. This class serves for the framework user as a base class for defining problem-related exceptions.

Naming convention:

All user-defined exception classes derived from Exc should have a name ending in Exc. The pattern is:

class ErrorconditionExc extends Exc { ... }

Named parameters

All public non-static fields of an exception object are considered named parameters of it. The corresponding placeholders in the message text patterns have the syntax: {name} with name being the name of the parameter.

This way of providing parameters is the recommended one for the following reasons: Firstly it is easier to translate a message text pattern into another language, if in the message text pattern there is an indication, for which purpose the message parameter is. The parameter name usually is a good hint to this. Secondly naming parameters is safer when adding or removing a parameter to/from an exception. Thirdly named parameters, for which a placeholder in the corresponding message text is missing, will not be suppressed. They will be appended in a standard format along with their name to the end of the message text.

The exception parameters can be substituted into the corresponding message text pattern in a desired locale format by class MsgText, which itself makes use of class java.text.MessageFormat.
See the usage examples Copy, AwtCopy, SwingCopy in directory demo.

Relation to Standards

Class java.text.MesageFormat expects the message parameters to be stored in an Object[]. So they are indexed parameters. We did not follow this way in order to be able to name parameters. All the rest of parameter formatting is done by and like java.text.MesageFormat, e.g. formatting a parameter of type java.util.Date with name today could be done by the following parameter formatting directive: {today,date}.

See Also:

Serialized Form

Constructor Summary

Exc(java.lang.String i_defaultMessageTextPattern)
Constructs an Exc with a default message text pattern.

Method Summary

java.lang.String	getDefaultMessageTextPattern() Returns the default message text pattern for i_throwable or null.
java.lang.String	getMessage() Returns the exception parameters of this object or null.

Methods inherited from class java.lang.Throwable

fillInStackTrace, getLocalizedMessage, printStackTrace, printStackTrace, printStackTrace, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Exc

public Exc(java.lang.String i_defaultMessageTextPattern)

Constructs an Exc with a default message text pattern. All public nonstatic fields are considered as named parameters of this exception object.

Method Detail

getMessage

public java.lang.String getMessage()

Returns the exception parameters of this object or null. They are in a compact, human readable format, e.g.:

{name}=myfile.dat  {directory}=C:\temp\data

Overrides:

getMessage in class java.lang.Throwable

getDefaultMessageTextPattern

public java.lang.String getDefaultMessageTextPattern()

Description copied from interface: MultexException

Returns the default message text pattern for i_throwable or null. Inserting the exception parameters into the message text pattern is done by class MsgText. Locale specific message text patterns are handled by MsgText, too.

Specified by:

getDefaultMessageTextPattern in interface MultexException