I have a Java class ExampleTuple2 that extends AbstractJSObject. My ExampleTuple2 has a toJSON method. I instantiate the object in JavaScript (nashorn) if I do a JSON.stringify(tuple2Instance) the result "undefined"
The API documentation for AbstractJSObject https://docs.oracle.com/javase/8/docs/jdk/api/nashorn/jdk/nashorn/api/scripting/AbstractJSObject.html states *"This is the base class for nashorn ScriptObjectMirror class. This class can also be subclassed by an arbitrary Java class. Nashorn will treat objects of such classes just like nashorn script objects. Usual nashorn operations like obj[i], obj.foo, obj.func(), delete obj.foo will be glued to appropriate method call of this class." * Should my toJSON method be calls when using JSON.stringify for this type of object? Example of the Java code. package org.eclairjs.nashorn.wrap; import jdk.nashorn.api.scripting.AbstractJSObject; import org.eclairjs.nashorn.Utils; public class ExampleTuple2 extends AbstractJSObject { public abstract class WrappedFunction extends AbstractJSObject { @Override public boolean isFunction() { return true; } } Object _1; Object _2; public ExampleTuple2(scala.Tuple2 tuple2) { _1=Utils.javaToJs(tuple2._1(),null); _2=Utils.javaToJs(tuple2._2(),null); } public ExampleTuple2(Object _1, Object _2) { this._1=_1; this._2=_2; } WrappedFunction F_toJSON = new WrappedFunction () { @Override public Object call(Object thiz, Object... args) { return "{\"0\":" + _1 + ",\"1\":" + _2 + "}" ; } }; WrappedFunction F_toString = new WrappedFunction () { @Override public Object call(Object thiz, Object... args) { return "(" + _1 + "," + _2 + ")" ; } }; WrappedFunction F_valueOf = new WrappedFunction () { @Override public Object call(Object thiz, Object... args) { return "(" + _1 + "," + _2 + ")"; } }; WrappedFunction F_1 = new WrappedFunction () { @Override public Object call(Object thiz, Object... args) { return _1; } }; WrappedFunction F_2 = new WrappedFunction () { @Override public Object call(Object thiz, Object... args) { return _2; } }; // get the value of that named property @Override public Object getMember(String name) { switch (name) { case "_1": return F_1; case "_2": return F_2; case "valueOf": return F_valueOf; case "toJSON": return F_toJSON; case "toString": return F_toString; } throw new RuntimeException("Tuple2."+name+" is not defined"); } @Override public boolean hasMember(String name) { switch (name) { case "_1": case "_2": case "valueOf": case "toJSON": case "toString": return true; } return super.hasMember(name); } } Example of the JavaScript code. var Tuple2 = Java.type('org.eclairjs.nashorn.wrap.ExampleTuple2'); var t = new Tuple2("value1", "value2"); print("t1 " + t._1()); print("t " + t); print(JSON.stringify(t));
