org.algernon.lang.java
Class JavaEvaluator

java.lang.Object
  org.algernon.lang.java.JavaEvaluator

All Implemented Interfaces:

ExternalLanguageEvaluator

public class JavaEvaluator

extends Object

implements ExternalLanguageEvaluator

Evaluator for java method calls and expressions. User: hewett Date: Dec 10, 2002 Time: 4:30:06 PM

Constructor Summary

JavaEvaluator()

Method Summary

Object	evaluateExpression(LispValue expression, Algernon algy) Evaluates a method call.
protected String	resolveClassName(String s) Returns a fully-qualified Java class name.
protected String	resolveMethodName(String s)
Boolean	toBoolean(Object any, Algernon algy) This method must return a Java Boolean value for any type of Object returned by the evaluateExpression method.

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaEvaluator

public JavaEvaluator()

Method Detail

toBoolean

public Boolean toBoolean(Object any,
                         Algernon algy)

This method must return a Java Boolean value for any type of Object returned by the evaluateExpression method. For example, null might correspond to Boolean.False,

Specified by:

toBoolean in interface ExternalLanguageEvaluator

Parameters:

any - any Java Object, including null.

Returns:

a Java Boolean instance.

evaluateExpression

public Object evaluateExpression(LispValue expression,
                                 Algernon algy)

Evaluates a method call. The class is instantiated, the method on that class is found, and the method is called on the object with the given parameters.

The method name should be class.method. The class lookup method looks for the class in two places: the given package (which may be no package) and the default package (org.algernonx). Case is significant in Java, but not in Algernon, so put the method name in double quotes.

   (:TEST (:JAVA ("org.mypackage.mysubpackage.UsefulRoutines.testMethod1" ?arg)))
 

Specified by:

evaluateExpression in interface ExternalLanguageEvaluator

Parameters:

expression - A method call in Java.

Returns:

the object returned by the method.

resolveMethodName

protected String resolveMethodName(String s)

resolveClassName

protected String resolveClassName(String s)

Returns a fully-qualified Java class name.

Parameters:

s -

Returns:

a fully-qualified Java class name.