sirius.kernel.health

Class Exceptions.ErrorHandler

java.lang.Object

sirius.kernel.health.Exceptions.ErrorHandler

Enclosing class:

Exceptions

public static class Exceptions.ErrorHandler
extends Object

Fluent API to create a HandledException based on given parameters

The intention is to use a call like:

 
    Exceptions.handler()
      .error(anException)     // Sets the exception to handle
      .to(aLogger)            // Sets the logger to use for logging
      .withNLSKey("nls.key")  // Sets the i18n key to create the error message
      .set("param",value)     // Sets a named parameter which occurs in the message
      .handle();              // logs an creates the HandledException
 
 

Since none of the methods must be called (except handle() of course), this provides a lot of flexibility and permits to handle several different error situations without having methods with long parameter lists and lots of null values.

The set(String, Object) method can be called several times to set different parameters. The reason why named parameters are used is because the resulting messages in the .properties files are easier to translate and also the order of the parameters can be different in different languages.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ErrorHandler(boolean processError) Use Exceptions.handle() to create an ErrorHandler

Method Summary

Modifier and Type	Method and Description
Exceptions.ErrorHandler	error(Throwable e) Specifies which exception leaded to the error being handled.
HandledException	handle() Generates and logs the resulting HandledException.
Exceptions.ErrorHandler	set(String parameter, Object value) Specifies a parameter which is replaced in the generated error message.
Exceptions.ErrorHandler	to(Log log) Specifies the logger which is used to log the generated exception.
String	toString()
Exceptions.ErrorHandler	withNLSKey(String key) Specifies the i18n key which is passed to NLS.fmtr(String) to create the internal formatter used to generate the translated error message.
Exceptions.ErrorHandler	withSystemErrorMessage(String englishMessagePattern, Object... params) Sets an untranslated error message, used by rare system errors.

Methods inherited from class java.lang.Object

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

Constructor Detail

ErrorHandler

protected ErrorHandler(boolean processError)

Use Exceptions.handle() to create an ErrorHandler

Parameters:

processError - determines if the error should be processed (logged and sent to all ExceptionHandler) or if just a HandledException is to be created

Method Detail

error

public Exceptions.ErrorHandler error(Throwable e)

Specifies which exception leaded to the error being handled.

Parameters:

e - the exception which needs to be attached to this error handler

Returns:

this in order to fluently call more methods on this handler

to

public Exceptions.ErrorHandler to(Log log)

Specifies the logger which is used to log the generated exception.

Parameters:

log - the logger used to log the generated HandledException

Returns:

this in order to fluently call more methods on this handler

withNLSKey

public Exceptions.ErrorHandler withNLSKey(String key)

Specifies the i18n key which is passed to NLS.fmtr(String) to create the internal formatter used to generate the translated error message.

This message may contain two parameters which don't need to be passed in: errorMessage and errorClass which contain the message of the exception being handled as well as the type name of it.

Parameters:

key - the translation key used to fetch the translated error message

Returns:

this in order to fluently call more methods on this handler

withSystemErrorMessage

public Exceptions.ErrorHandler withSystemErrorMessage(String englishMessagePattern,
                                                      Object... params)

Sets an untranslated error message, used by rare system errors.

Still a translated message will be created, which notifies the user about the system error and provides the untranslated error message, generated by this method. These messages should be in english.

Parameters:

englishMessagePattern - contains a pattern used to generate the error message. May contain placeholders as understood by Strings.apply(String, Object...).

params - parameters used to format the resulting error message based on the given pattern

Returns:

this in order to fluently call more methods on this handler

set

public Exceptions.ErrorHandler set(String parameter,
                                   Object value)

Specifies a parameter which is replaced in the generated error message.

Parameters:

parameter - the name of the parameter which should be replaced. This must occur as ${parameter} in the translated message to be replaced

value - the value to be used as replacement for the parameter. The given value will be converted to a string using NLS.toUserString(Object)

Returns:

this in order to fluently call more methods on this handler

handle

public HandledException handle()

Generates and logs the resulting HandledException.

The generated exception can be either thrown (it subclasses RuntimeException and therefore needs no throws clause). Alternatively it may be passed along or even be just discarded.

Returns:

a HandledException which notifies surrounding calls that an error occurred, which has already been taken care of.

toString

public String toString()

Overrides:

toString in class Object