Class Exceptions

Object

Static

Exceptions

public final class Exceptions
extends Static

Static methods working with Exception instances.

Since:

0.3

Method Summary

Modifier and Type	Method	Description
static String	format­Chained­Messages(Locale locale, String header, Throwable cause)	Returns a string which contains the given message on the first line, followed by the localized message of the given exception on the next line.
static String	get­Localized­Message(Throwable exception, Locale locale)	Returns the message of the given exception, localized in the given locale if possible.
static boolean	message­Equals(Throwable first, Throwable second)	Returns true if the given exceptions are of the same class and contains the same message.
static Exception	unwrap(Exception exception)	If the given exception is a wrapper for another exception, returns the unwrapped exception.

Methods inherited from class Object

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

Method Details

getLocalizedMessage

public static String getLocalizedMessage(Throwable exception,
 Locale locale)

Returns the message of the given exception, localized in the given locale if possible. Some exceptions created by SIS can format a message in different locales. This method returns such localized message if possible, or fallback on the standard JDK methods otherwise. More specifically:

• If the given exception is null, then this method returns null.
• Otherwise if the given locale is null, then this method returns Throwable.get­Message(). This is consistent with the Localized policy saying that null locale stands for "unlocalized" message (usually in English) or message in the JVM default locale.
• Otherwise if the given exception is an instance of Localized­Exception providing a non-null international message, then this method returns the result of International­String.to­String(Locale).
• Otherwise this method returns Throwable.get­Localized­Message().

Parameters:

exception - the exception from which to get the localize message, or null.

locale - the preferred locale for the message, or null for the JVM default locale. This locale is honored on a best effort basis only.

Returns:

the message in the given locale if possible, or null if the exception argument was null or if the exception does not contain a message.

See Also:

• Localized­Exception.get­Localized­Message()

messageEquals

public static boolean messageEquals(Throwable first,
 Throwable second)

Returns true if the given exceptions are of the same class and contains the same message. This method does not compare the stack trace, cause or suppressed exceptions.

Parameters:

first - the first exception, or null.

second - the second exception, or null.

Returns:

true if both exceptions are null, or both exceptions are non-null, of the same class and with the same message.

Since:

1.0

formatChainedMessages

public static String formatChainedMessages(Locale locale,
 String header,
 Throwable cause)

Returns a string which contains the given message on the first line, followed by the localized message of the given exception on the next line. If the exception has a causes, then the class name and the localized message of the cause are formatted on the next line. The process is repeated for the whole cause chain, omitting duplicated messages. This method does not format the stack trace.

Special cases

SQLException is handled is a special way by giving precedence to SQLException.get­Next­Exception() over Throwable.get­Cause().

When to use

This method should not be used when the given exception will be reported through, for example, Throwable.init­Cause(Throwable) or Log­Record.set­Thrown(Throwable), because the redundancy may be confusing. This method is rather for situations where the exception will be discarded or hidden.

Parameters:

locale - the preferred locale for the exception message, or null.

header - the message to insert on the first line, or null if none.

cause - the exception, or null if none.

Returns:

the formatted message, or null if both the header was null and no exception provide a message.

unwrap

public static Exception unwrap(Exception exception)

If the given exception is a wrapper for another exception, returns the unwrapped exception. Otherwise returns the given argument unchanged. An exception is considered a wrapper if:

• It is an instance of Invocation­Target­Exception (could be wrapping anything).
• It is an instance of Execution­Exception (could be wrapping anything).
• It is an instance of Backing­Store­Exception (typically wrapping a checked exception).
• It is an instance of Unchecked­IOException (wrapping a IOException).
• It is an instance of Directory­Iterator­Exception (wrapping a IOException).
• It is a parent type of its cause. For example, some JDBC drivers wrap SQLException in another SQLException without additional information. When the wrapper is a parent class of the cause, details about the reason are less accessible.

This method uses only the exception class as criterion; it does not verify if the exception messages are the same.

Parameters:

exception - the exception to unwrap (may be null.

Returns:

the unwrapped exception (may be the given argument itself).

Since:

0.8