org.apache.commons.jexl.util.introspection

Class IntrospectorBase

java.lang.Object

org.apache.commons.jexl.util.introspection.IntrospectorBase

Direct Known Subclasses:

Introspector

public class IntrospectorBase
extends java.lang.Object

This basic function of this class is to return a Method object for a particular class given the name of a method and the parameters to the method in the form of an Object[]

The first time the Introspector sees a class it creates a class method map for the class in question. Basically the class method map is a Hastable where Method objects are keyed by a concatenation of the method name and the names of classes that make up the parameters. For example, a method with the following signature: public void method(String a, StringBuffer b) would be mapped by the key: "method" + "java.lang.String" + "java.lang.StringBuffer" This mapping is performed for all the methods in a class and stored for

Since:

1.0

Version:

$Id: IntrospectorBase.java 584046 2007-10-12 05:14:37Z proyal $

Author:

Jason van Zyl, Bob McWhirter, Attila Szegedi, Paulo Gaspar, Henning P. Schmiedehausen

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Map	classMethodMaps Holds the method maps for the classes we know about, keyed by Class object.

Constructor Summary

Constructors

Constructor and Description
IntrospectorBase(org.apache.commons.logging.Log rlog)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	clearCache() Clears the classmap and classname caches.
protected ClassMap	createClassMap(java.lang.Class c) Creates a class map for specific class and registers it in the cache.
java.lang.reflect.Method	getMethod(java.lang.Class c, java.lang.String name, java.lang.Object[] params) Gets the method defined by name and params for the Class c.

Methods inherited from class java.lang.Object

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

Field Detail

classMethodMaps

protected final java.util.Map classMethodMaps

Holds the method maps for the classes we know about, keyed by Class object.

Constructor Detail

IntrospectorBase

public IntrospectorBase(org.apache.commons.logging.Log rlog)

Method Detail

getMethod

public java.lang.reflect.Method getMethod(java.lang.Class c,
                                 java.lang.String name,
                                 java.lang.Object[] params)
                                   throws java.lang.IllegalArgumentException,
                                          MethodMap.AmbiguousException

Gets the method defined by name and params for the Class c.

Parameters:

c - Class in which the method search is taking place

name - Name of the method being searched for

params - An array of Objects (not Classes) that describe the the parameters

Returns:

The desired Method object.

Throws:

java.lang.IllegalArgumentException - When the parameters passed in can not be used for introspection.

MethodMap.AmbiguousException - When the method map contains more than one match for the requested signature.

createClassMap

protected ClassMap createClassMap(java.lang.Class c)

Creates a class map for specific class and registers it in the cache. Also adds the qualified name to the name->class map for later Classloader change detection.

Parameters:

c - class.

Returns:

a ClassMap

clearCache

protected void clearCache()

Clears the classmap and classname caches.