GetToKnowBindingsAndScopes.java Source code

Introduction

Here is the source code for GetToKnowBindingsAndScopes.java

Source

import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

public class GetToKnowBindingsAndScopes {
    public static void main(String[] args) {
        ScriptEngineManager manager = new ScriptEngineManager();
        manager.put("global", "global bindings");

        dumpBindings(manager.getBindings());
        ScriptEngine engine = manager.getEngineByExtension("js");
        engine.put("engine", "engine bindings");

        dumpBindings(engine.getBindings(ScriptContext.GLOBAL_SCOPE));

        dumpBindings(engine.getBindings(ScriptContext.ENGINE_SCOPE));

        try {
            Bindings bindings = engine.createBindings();
            bindings.put("engine", "overridden engine bindings");
            bindings.put("app", new GetToKnowBindingsAndScopes());
            bindings.put("bindings", bindings);
            engine.eval("app.dumpBindings (bindings);", bindings);
        } catch (ScriptException se) {
            System.err.println(se.getMessage());
        }

        ScriptEngine engine2 = manager.getEngineByExtension("js");
        engine2.put("engine2", "engine2 bindings");

        dumpBindings(engine2.getBindings(ScriptContext.GLOBAL_SCOPE));
        dumpBindings(engine2.getBindings(ScriptContext.ENGINE_SCOPE));
        dumpBindings(engine.getBindings(ScriptContext.ENGINE_SCOPE));
    }

    public static void dumpBindings(Bindings bindings) {
        if (bindings == null)
            System.out.println("  No bindings");
        else
            for (String key : bindings.keySet())
                System.out.println("  " + key + ": " + bindings.get(key));
        System.out.println();
    }
}