Package org.apache.velocity.util.introspection

Class IntrospectorBase

java.lang.Object

org.apache.velocity.util.introspection.IntrospectorBase

Direct Known Subclasses:

Introspector

public abstract class IntrospectorBase
extends Object

Lookup a a Method object for a particular class given the name of a method and its parameters. 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 Hashtable 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.

Version:

$Id$

Author:

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

Field Summary

Fields

Modifier and Type	Field	Description
protected final org.slf4j.Logger	log	Class logger

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	IntrospectorBase(org.slf4j.Logger log, TypeConversionHandler conversionHandler)	C'tor.

Method Summary

Modifier and Type	Method	Description
Field	getField(Class<?> c, String name)	Gets the field defined by name.
protected IntrospectorCache	getIntrospectorCache()	Return the internal IntrospectorCache object.
Method	getMethod(Class<?> c, String name, 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 Details

log

protected final org.slf4j.Logger log

Class logger

Constructor Details

IntrospectorBase

protected IntrospectorBase(org.slf4j.Logger log,
 TypeConversionHandler conversionHandler)

C'tor.

Parameters:

log - logger

conversionHandler - conversion handler

Method Details

getMethod

public Method getMethod(Class<?> c,
 String name,
 Object[] params)
                 throws 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:

NullPointerException - When the parameters passed in can not be used for introspection because null.

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

getField

public Field getField(Class<?> c,
 String name)
               throws IllegalArgumentException

Gets the field defined by name.

Parameters:

c - Class in which the method search is taking place

name - Name of the field being searched for

Returns:

The desired Field object.

Throws:

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

getIntrospectorCache

protected IntrospectorCache getIntrospectorCache()

Return the internal IntrospectorCache object.

Returns:

The internal IntrospectorCache object.

Since:

1.5