Package org.apache.tapestry5.commons.internal.services

Class TypeCoercerImpl

java.lang.Object

org.apache.tapestry5.commons.internal.util.LockSupport

org.apache.tapestry5.commons.internal.services.TypeCoercerImpl

All Implemented Interfaces:

TypeCoercer

public class TypeCoercerImpl
extends LockSupport
implements TypeCoercer

Constructor Summary

Constructors

Constructor	Description
TypeCoercerImpl(java.util.Map<CoercionTuple.Key,CoercionTuple> tuples)

Method Summary

Modifier and Type	Method	Description
void	clearCache()	Clears cached information stored by the TypeCoercer.
java.lang.Object	coerce(java.lang.Object input, java.lang.Class targetType)	Performs a coercion from an input type to a desired output type.
<S,T> java.lang.String	explain(java.lang.Class<S> sourceType, java.lang.Class<T> targetType)	Used primarily inside test suites, this method performs the same steps as TypeCoercer.coerce(Object, Class), but returns a string describing the series of coercions, such as "Object --> String --> Long --> Integer".
<S,T> Coercion<S,T>	getCoercion(java.lang.Class<S> sourceType, java.lang.Class<T> targetType)	Given a source and target type, computes the coercion that will be used.

Methods inherited from class org.apache.tapestry5.commons.internal.util.LockSupport

acquireReadLock, downgradeWriteLockToReadLock, releaseReadLock, releaseWriteLock, takeWriteLock, upgradeReadLockToWriteLock

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeCoercerImpl

public TypeCoercerImpl(java.util.Map<CoercionTuple.Key,CoercionTuple> tuples)

Method Detail

coerce

public java.lang.Object coerce(java.lang.Object input,
                               java.lang.Class targetType)

Description copied from interface: TypeCoercer

Performs a coercion from an input type to a desired output type. When the target type is a primitive, the actual conversion will be to the equivalent wrapper type. In some cases, the TypeCoercer will need to search for an appropriate coercion, and may even combine existing coercions to form new ones; in those cases, the results of the search are cached. The TypeCoercer also caches the results of a coercion search.

Specified by:

coerce in interface TypeCoercer

targetType - defines the target type

Returns:

the coerced value

getCoercion

public <S,T> Coercion<S,T> getCoercion(java.lang.Class<S> sourceType,
                                                   java.lang.Class<T> targetType)

Description copied from interface: TypeCoercer

Given a source and target type, computes the coercion that will be used. Note: holding the returned coercion past the time when the cache is cleared can cause a memory leak, especially in the context of live reloading (wherein holding a reference to a single class make keep an entire ClassLoader from being reclaimed).

Specified by:

getCoercion in interface TypeCoercer

Type Parameters:

S - source type (input)

T - target type (output)

Parameters:

sourceType - type to coerce from

targetType - defines the target type

Returns:

the coercion that will ultimately be used

explain

public <S,T> java.lang.String explain(java.lang.Class<S> sourceType,
                                            java.lang.Class<T> targetType)

Description copied from interface: TypeCoercer

Used primarily inside test suites, this method performs the same steps as TypeCoercer.coerce(Object, Class), but returns a string describing the series of coercions, such as "Object --> String --> Long --> Integer".

Specified by:

explain in interface TypeCoercer

Type Parameters:

S - source type (input)

T - target type (output)

Parameters:

sourceType - the source coercion type (use void.class for coercions from null)

targetType - defines the target type

Returns:

a string identifying the series of coercions, or the empty string if no coercion is necessary

clearCache

public void clearCache()

Description copied from interface: TypeCoercer

Clears cached information stored by the TypeCoercer.

Specified by:

clearCache in interface TypeCoercer