org.apache.velocity.util.introspection
Class IntrospectorBase

java.lang.Object
  extended by 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: IntrospectorBase.java 1329799 2012-04-24 15:41:21Z cbrisson $
Author:
Jason van Zyl, Bob McWhirter, Attila Szegedi, Paulo Gaspar, Henning P. Schmiedehausen, Candid Dauth

Field Summary
protected  Log log
          Class logger
 
Constructor Summary
protected IntrospectorBase(Log log)
          C'tor.
 
Method Summary
 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 Detail

log

protected final Log log
Class logger

Constructor Detail

IntrospectorBase

protected IntrospectorBase(Log log)
C'tor.

Method Detail

getMethod

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

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


Copyright © 2000-2012 The Apache Software Foundation. All Rights Reserved.