org.apache.drill.common

Class DeferredException

java.lang.Object

org.apache.drill.common.DeferredException

All Implemented Interfaces:

AutoCloseable

public class DeferredException
extends Object
implements AutoCloseable

Collects one or more exceptions that may occur, using suppressed exceptions. When this AutoCloseable is closed, if there was an exception added, it will be thrown. If more than one exception was added, then all but the first will be added to the first as suppressed exceptions.

This class is thread safe.

Constructor Summary

Constructors

Constructor and Description
DeferredException() Constructor.
DeferredException(org.apache.drill.shaded.guava.com.google.common.base.Supplier<Exception> exceptionSupplier) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addException(Exception exception) Add an exception.
void	addThrowable(Throwable throwable)
void	close()
Exception	getAndClear()
Exception	getException() Get the deferred exception, if there is one.
void	suppressingClose(AutoCloseable autoCloseable) Close the given AutoCloseable, suppressing any exceptions that are thrown.
void	throwAndClear() If an exception exists, will throw the exception and then clear it.

Methods inherited from class java.lang.Object

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

Constructor Detail

DeferredException

public DeferredException()

Constructor.

DeferredException

public DeferredException(org.apache.drill.shaded.guava.com.google.common.base.Supplier<Exception> exceptionSupplier)

Constructor. This constructor accepts a Supplier that can be used to create the root exception iff any other exceptions are added. For example, in a series of resources closures in a close(), if any of the individual closures fails, the root exception should come from the current class, not from the first subordinate close() to fail. This can be used to provide an exception in that case which will be the root exception; the subordinate failed close() will be added to that exception as a suppressed exception.

Parameters:

exceptionSupplier - lazily supplies what will be the root exception if any exceptions are added

Method Detail

addException

public void addException(Exception exception)

Add an exception. If this is the first exception added, it will be the one that is thrown when this is closed. If not the first exception, then it will be added to the suppressed exceptions on the first exception.

Parameters:

exception - the exception to add

addThrowable

public void addThrowable(Throwable throwable)

getException

public Exception getException()

Get the deferred exception, if there is one. Note that if this returns null, the result could change at any time.

Returns:

the deferred exception, or null

getAndClear

public Exception getAndClear()

throwAndClear

public void throwAndClear()
                   throws Exception

If an exception exists, will throw the exception and then clear it. This is so in cases where want to reuse DeferredException, we don't double report the same exception.

Throws:

Exception

suppressingClose

public void suppressingClose(AutoCloseable autoCloseable)

Close the given AutoCloseable, suppressing any exceptions that are thrown. If an exception is thrown, the rules for addException(Exception) are followed.

Parameters:

autoCloseable - the AutoCloseable to close; may be null

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception