org.apache.tapestry5.ioc.internal.util
Class Defense

java.lang.Object
  org.apache.tapestry5.ioc.internal.util.Defense

public final class Defense
extends Object

Static utility methods for defensive programming.

Method Summary

static <T> T	cast(Object parameterValue, Class<T> type, String parameterName) Checks that the provided value is not null, and may be cast to the desired type.
static String	notBlank(String value, String parameterName) Checks that a parameter value is not null and not empty.
static <T> T	notNull(T value, String parameterName) Checks that a method parameter value is not null, and returns it.

Methods inherited from class java.lang.Object

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

Method Detail

notNull

public static <T> T notNull(T value,
                            String parameterName)

Checks that a method parameter value is not null, and returns it.

Type Parameters:

T - the value type

Parameters:

value - the value (which is checked to ensure non-nullness)

parameterName - the name of the parameter, used for exception messages

Returns:

the value

Throws:

IllegalArgumentException - if the value is null

notBlank

public static String notBlank(String value,
                              String parameterName)

Checks that a parameter value is not null and not empty.

Parameters:

value - value to check (which is returned)

parameterName - the name of the parameter, used for exception messages

Returns:

the value, trimmed, if non-blank

Throws:

IllegalArgumentException - if the value is null or empty

cast

public static <T> T cast(Object parameterValue,
                         Class<T> type,
                         String parameterName)

Checks that the provided value is not null, and may be cast to the desired type.

Type Parameters:

T -

Parameters:

parameterValue -

type -

parameterName -

Returns:

the casted value

Throws:

IllegalArgumentException - if the value is null, or is not assignable to the indicated type