org.zkoss.bind.paranamer

Class CachingParanamer

java.lang.Object

org.zkoss.bind.paranamer.CachingParanamer

All Implemented Interfaces:

Paranamer

Direct Known Subclasses:

CachingParanamer.WithoutWeakReferences

public class CachingParanamer
extends java.lang.Object
implements Paranamer

Implementation of Paranamer which delegate to another Paranamer implementation, adding caching functionality to speed up usage. It also uses a WeakHashmap as an implementation detail (wrapped in Collections.synchronizedMap(..)), to allow large usages to garbage collect things as big as whole classloaders (after working through all the refs that originated from that classloader). Tomcat and other 'containers' do this during hot application deployment, undeployment and most importantly for Paranamer redeployment. Basically, this will allow a perm-gen usage keeps growing scenario.

Author:

Paul Hammant, Mauro Talevi

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CachingParanamer.WithoutWeakReferences This implementation has a better concurrent design (ConcurrentHashMap) which has a better strategy to implement concurrency: segments instead of synchronized.

Field Summary

Fields inherited from interface org.zkoss.bind.paranamer.Paranamer

EMPTY_NAMES

Constructor Summary

Constructors

Constructor and Description
CachingParanamer(Paranamer delegate) Specify a Paranamer instance to delegates to.

Method Summary

Modifier and Type	Method and Description
java.lang.String[]	lookupParameterNames(java.lang.reflect.AccessibleObject methodOrConstructor) Lookup the parameter names of a given method.
java.lang.String[]	lookupParameterNames(java.lang.reflect.AccessibleObject methodOrCtor, boolean throwExceptionIfMissing) Lookup the parameter names of a given method.
protected java.util.Map<java.lang.reflect.AccessibleObject,java.lang.String[]>	makeMethodCache()

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingParanamer

public CachingParanamer(Paranamer delegate)

Specify a Paranamer instance to delegates to.

Parameters:

delegate - the paranamer instance to use

Method Detail

makeMethodCache

protected java.util.Map<java.lang.reflect.AccessibleObject,java.lang.String[]> makeMethodCache()

lookupParameterNames

public java.lang.String[] lookupParameterNames(java.lang.reflect.AccessibleObject methodOrConstructor)

Description copied from interface: Paranamer

Lookup the parameter names of a given method.

Specified by:

lookupParameterNames in interface Paranamer

Parameters:

methodOrConstructor - the Method or Constructor for which the parameter names are looked up.

Returns:

A list of the parameter names.

lookupParameterNames

public java.lang.String[] lookupParameterNames(java.lang.reflect.AccessibleObject methodOrCtor,
                                               boolean throwExceptionIfMissing)

Description copied from interface: Paranamer

Lookup the parameter names of a given method.

Specified by:

lookupParameterNames in interface Paranamer

Parameters:

methodOrCtor - the Method or Constructor for which the parameter names are looked up.

throwExceptionIfMissing - whether to throw an exception if no Paranamer data found (versus return null).

Returns:

A list of the parameter names.