Package org.eclipse.rdf4j.federated.exception

Class ExceptionUtil

java.lang.Object

org.eclipse.rdf4j.federated.exception.ExceptionUtil

public class ExceptionUtil
extends Object

Convenience functions to handle exceptions.

Author:

Andreas Schwarte

Field Summary

Fields

Modifier and Type	Field	Description
protected static final Pattern	httpErrorPattern	Regex pattern to identify http error codes from the title of the returned document: Matcher m = httpErrorPattern.matcher("[..] 503 Service Unavailable [..]"); if (m.matches()) { System.out.println("HTTP Error: " + m.group(1); }
protected static final org.slf4j.Logger	log

Constructor Summary

Constructors

Constructor	Description
ExceptionUtil()

Method Summary

Modifier and Type	Method	Description
static <E extends Exception> E	changeExceptionMessage(String msgPrefix, E ex, Class<E> exClazz)	If possible change the message text of the specified exception.
static String	getExceptionString(String msg, Throwable ex)	Return the exception in a convenient representation, i.e.
static Exception	toException(Throwable t)	Converts the Throwable to an Exception.
static QueryEvaluationException	toQueryEvaluationException(Throwable t)	Converts the given Throwable to a QueryEvaluationException.
static QueryEvaluationException	traceExceptionSource(Endpoint endpoint, Throwable ex, String additionalInfo)	Trace the exception source within the exceptions to identify the originating endpoint.
static QueryEvaluationException	traceExceptionSourceAndRepair(Endpoint endpoint, Throwable ex, String additionalInfo)	Repair the connection and then trace the exception source.

Methods inherited from class java.lang.Object

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

Field Details

log

protected static final org.slf4j.Logger log

httpErrorPattern

protected static final Pattern httpErrorPattern

Regex pattern to identify http error codes from the title of the returned document: Matcher m = httpErrorPattern.matcher("[..] [..]"); if (m.matches()) { System.out.println("HTTP Error: " + m.group(1); }

Constructor Details

ExceptionUtil

public ExceptionUtil()

Method Details

traceExceptionSource

public static QueryEvaluationException traceExceptionSource(Endpoint endpoint,
 Throwable ex,
 String additionalInfo)

Trace the exception source within the exceptions to identify the originating endpoint. The message of the provided exception is adapted to "@ endpoint.getId() - %orginalMessage".

Note that in addition HTTP error codes are extracted from the title, if the exception resulted from an HTTP error, such as for instance "503 Service unavailable"

Parameters:

endpoint - the the endpoint

ex - the exception

additionalInfo - additional information that might be helpful, e.g. the subquery

Returns:

a modified exception with endpoint source

traceExceptionSourceAndRepair

public static QueryEvaluationException traceExceptionSourceAndRepair(Endpoint endpoint,
 Throwable ex,
 String additionalInfo)

Repair the connection and then trace the exception source.

Parameters:

endpoint -

ex -

Returns:

the exception

getExceptionString

public static String getExceptionString(String msg,
 Throwable ex)

Return the exception in a convenient representation, i.e. '%msg% (%CLASS%): %ex.getMessage()%'

Parameters:

msg -

ex -

Returns:

the exception in a convenient representation

changeExceptionMessage

public static <E extends Exception> E changeExceptionMessage(String msgPrefix,
 E ex,
 Class<E> exClazz)

If possible change the message text of the specified exception. This is only possible if the provided exception has a public constructor with String and Throwable as argument. The new message is set to 'msgPrefix. ex.getMessage()', all other exception elements remain the same.

Type Parameters:

E -

Parameters:

msgPrefix -

ex -

exClazz -

Returns:

the updated exception

toException

public static Exception toException(Throwable t)

Converts the Throwable to an Exception. If it is already of type exception, it is returned as is. Otherwise, we create a new QueryEvaluationException, and attach the stack trace and a meaningful message.

Parameters:

t -

Returns:

the Exception

toQueryEvaluationException

public static QueryEvaluationException toQueryEvaluationException(Throwable t)

Converts the given Throwable to a QueryEvaluationException. If it is already of type QueryEvaluationException no transformation is done, otherwise the throwable is wrapped.

Parameters:

t -

Returns:

the QueryEvaluationException