Package com.intergral.deep.agent.tracepoint.evaluator

Class NashornReflectEvaluator

java.lang.Object

com.intergral.deep.agent.api.plugin.AbstractEvaluator

com.intergral.deep.agent.tracepoint.evaluator.NashornReflectEvaluator

All Implemented Interfaces:

IEvaluator

public class NashornReflectEvaluator
extends AbstractEvaluator

This evaluator uses the Nashorn JS engine that is available in some version of Java.

This engine was removed in Java 14.

There are limitations of this engine.

1. It can only access public methods/fields 2. It can access 'private' fields only if there is a public getter 3. We have to load this via reflection as we need to load from the app classloader not the boot classloader

Method Summary

Modifier and Type	Method	Description
Object	evaluateExpression(String expression, Map<String,Object> values)	Evaluate an expression to the value.
static IEvaluator	loadEvaluator(ClassLoader loader)	Load the evaluator.

Methods inherited from class com.intergral.deep.agent.api.plugin.AbstractEvaluator

evaluate, objectToBoolean

Methods inherited from class java.lang.Object

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

Method Detail

loadEvaluator

public static IEvaluator loadEvaluator(ClassLoader loader)

Load the evaluator.

Parameters:

loader - the class loader to use

Returns:

the evaluator or null if Nashorn is not available.

evaluateExpression

public Object evaluateExpression(String expression,
                                 Map<String,Object> values)
                          throws Throwable

Description copied from interface: IEvaluator

Evaluate an expression to the value.

Parameters:

expression - the expression to evaluate

values - the variables that the expression can evaluate against

Returns:

the result of the expression

Throws:

Throwable - if the expression fails