Develop Reference

Is it possible to run playwright script (written in TS) through Java code? [duplicate]

I want to run JavaScript code at the server side. I want to manipulate result returned by JavaScript inside my Java code. How can it be done?

The start is clearly to look into rhino.
I think you will find this 3 links very useful
JavaScript EE, Part 1: Run JavaScript files on the server side
JavaScript EE, Part 2: Call remote JavaScript functions with Ajax
JavaScript EE, Part 3: Use Java scripting API with JSP
You can also have a look to helma
Helma is a server-side Javascript environment and web application framework for fast and efficient scripting and serving of your websites and Internet applications.
Helma is written in Java and employs Javascript for its server-side scripting environment ...

The other answers are correct that if you want to execute Javascript on the server side, you'd need to evaluate it in the context of a JS runtime.
However, I'm not convinced that this is exactly what you're asking. I think there may be a chance that you want to run some "typical" JS functionality that relates to how the page is displayed on the client's machine or interacted with on the client - and that will not be possible to run on the server side.
As a concrete examples:
If you want to run some kind of algorithm in JS without porting it to Java - say, you have some opaque Javascript code that generates a particular sequence given a seed - this would work fine if you run it on Rhino on the server.
If you want to invoke a Javascript function while creating the page, rather than while it's running - say, to get the user's colour depth/screen resolution and change how the page is generated - then this will not be possible from the server, as there is no client at this point to query.
Broadly speaking, any Javascript that involves document or navigator or even any elements of the page itself, is likely to fall into the latter category.
If you really need to get information about the client environment in order to control how the page is rendered, this must be extracted from the client on the previous page, and encoded into the request (as query parameters or form data). These parameters can then be read directly on the server and used to control the output.
Remember that when your code is running on the server side, you're creating a page (ultimately a bunch of HTML, CSS and JS) that will be sent to the client once it's done - at this point there is no client yet and so you can't interact with them.
Apologies if I've got the wrong end of the stick on this one, but this type of question is typically asked by people who haven't grasped the client/server separation.

You need a JS runtime inside of a Java runtime. One way to do this is Rhino

You execute the JavaScript with Rhino, a JavaScript library for Java.

You can use RHINO or NASHORN.
public class RhinoApp {
private String simpleAdd = "var z=9; z*=9";
public void runJavaScript() {
Context jsCx = Context.enter();
Context.getCurrentContext().setOptimizationLevel(-1);
ScriptableObject scope = jsCx.initStandardObjects();
Object result = jsCx.evaluateString(scope, simpleAdd , "formula", 0, null);
Context.exit();
System.out.println(result);
}

This example should clearly state how to load, evaluate and execute a Javascript function in Java:
ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("JavaScript");
URI source_js = JavascriptExecutor.class.getResource("/file.js").toURI();
String source_text = Files.readAllLines(Paths.get(source_js)).stream().collect(Collectors.joining("\n"));
engine.eval(source_text);
Invocable inv = (Invocable) engine;
Object returnValue = inv.invokeFunction("functionJsName", "functionJsParameter");
System.out.println(returnValue.toString());

How access the iframe elements from a java code

I need to access the value of div element inside an iframe from java code. The iframe is on a web browser and java code is on local server. I need this to test the values in iframe. I am new in coding/automation, any suggestion on how this can be done will be helpful. I found on net how to access through JS but i need to get the values in my java code. I am not using selenium web driver but original browser.
Any suggestion/pointer will be helpful, Thanks SOF!!

If you have solution in JS then you can use the Java Scripting API
Below the basic example:
import javax.script.*;
public class EvalScript {
public static void main(String[] args) throws Exception {
// create a script engine manager
ScriptEngineManager factory = new ScriptEngineManager();
// create a JavaScript engine
ScriptEngine engine = factory.getEngineByName("JavaScript");
// evaluate JavaScript code from String
engine.eval("print('Hello, World')");
}
}

Use ScriptEngine to bind global javascript functions from java code [duplicate]

The JSR223 Bindings class allows you to expose arbitrary Java objects to scripting languages. But they have to be objects. I would like to define a function quit() that can be called from the scripting environment that turns into quitObject.run() in Java. But JSR223 doesn't define the concept of a function object. Is there a language-independent way to do the following in Javascript, namely to take a Runnable() and create a function in the scripting environment?
static private Object asFunction(ScriptEngine engine, Runnable r)
throws ScriptException
{
final Bindings bindings = engine.createBindings();
bindings.put("r", r);
return engine.eval(
"(function (r) { var f = function() { r.run(); }; return f;})(r)",
bindings);
}
Runnable quitObject = /* get/create a Runnable here */
Bindings bindings = engine.createBindings();
bindings.put("quit", asFunction(engine, quitObject));
With the builtin Javascript support for JSR223 this creates a sun.org.mozilla.javascript.internal.InterpretedFunction which does what I want. But it obviously won't work in Jython or whatever, and I'd like to make this language-independent.
I don't want my script users to have to type quitObject.run() as that's clumsy, and I don't want to parse script input to find quit() as it could be buried within other code.

If you look at javascript engine source code you'll find how oracle/sun implemented 2 functions (print, and println) which are magically (or not so magically) present when you fire up your engine.
Those function are 'scripted' , which is more or less what you did.
What I would do is : load and evaluate a bootstrap.[language_extension] before evaluating any other input in the new context.
You could easily create such scripts for each language you intend to support.

How to pass an object from Java to JavaScript using Rhino

I am working on a Java program where an object needs to have user-customization behavior for one function. I am implementing this using Mozilla Rhino, JavaScript and Java.
I cannot figure out how to take the already instantiated object and pass it to a pre-written script.
I have looked through many tutorials on Rhino, and none have given an example like this. Any advice or links would be greatly appreciated.
Thank you for your time.

This answer to another question passes an object, data, from Java to Rhino Javascript.
I have no idea whether or not it works (well I suppose it does). Here are the relevant parts:
public static class data {
Double value = 1.0d;
}
ScriptEngine engine = new ScriptEngineManager().getEngineByName ("rhino");
data data = new data();
Context.enter().getWrapFactory().setJavaPrimitiveWrap(false);
engine.eval("function test(data) { return data.get('value1') + 5;};");
System.out.println("Result:" + ((Invocable)engine).invokeFunction("test", data));
(I didn't know about that setJavaPrimitiveWrap(), here is some WrapFactory Javadoc.)

How can I run JavaScript code at server side Java code?

I want to run JavaScript code at the server side. I want to manipulate result returned by JavaScript inside my Java code. How can it be done?

The start is clearly to look into rhino.
I think you will find this 3 links very useful
JavaScript EE, Part 1: Run JavaScript files on the server side
JavaScript EE, Part 2: Call remote JavaScript functions with Ajax
JavaScript EE, Part 3: Use Java scripting API with JSP
You can also have a look to helma
Helma is a server-side Javascript environment and web application framework for fast and efficient scripting and serving of your websites and Internet applications.
Helma is written in Java and employs Javascript for its server-side scripting environment ...

The other answers are correct that if you want to execute Javascript on the server side, you'd need to evaluate it in the context of a JS runtime.
However, I'm not convinced that this is exactly what you're asking. I think there may be a chance that you want to run some "typical" JS functionality that relates to how the page is displayed on the client's machine or interacted with on the client - and that will not be possible to run on the server side.
As a concrete examples:
If you want to run some kind of algorithm in JS without porting it to Java - say, you have some opaque Javascript code that generates a particular sequence given a seed - this would work fine if you run it on Rhino on the server.
If you want to invoke a Javascript function while creating the page, rather than while it's running - say, to get the user's colour depth/screen resolution and change how the page is generated - then this will not be possible from the server, as there is no client at this point to query.
Broadly speaking, any Javascript that involves document or navigator or even any elements of the page itself, is likely to fall into the latter category.
If you really need to get information about the client environment in order to control how the page is rendered, this must be extracted from the client on the previous page, and encoded into the request (as query parameters or form data). These parameters can then be read directly on the server and used to control the output.
Remember that when your code is running on the server side, you're creating a page (ultimately a bunch of HTML, CSS and JS) that will be sent to the client once it's done - at this point there is no client yet and so you can't interact with them.
Apologies if I've got the wrong end of the stick on this one, but this type of question is typically asked by people who haven't grasped the client/server separation.

You need a JS runtime inside of a Java runtime. One way to do this is Rhino

You execute the JavaScript with Rhino, a JavaScript library for Java.

You can use RHINO or NASHORN.
public class RhinoApp {
private String simpleAdd = "var z=9; z*=9";
public void runJavaScript() {
Context jsCx = Context.enter();
Context.getCurrentContext().setOptimizationLevel(-1);
ScriptableObject scope = jsCx.initStandardObjects();
Object result = jsCx.evaluateString(scope, simpleAdd , "formula", 0, null);
Context.exit();
System.out.println(result);
}

This example should clearly state how to load, evaluate and execute a Javascript function in Java:
ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("JavaScript");
URI source_js = JavascriptExecutor.class.getResource("/file.js").toURI();
String source_text = Files.readAllLines(Paths.get(source_js)).stream().collect(Collectors.joining("\n"));
engine.eval(source_text);
Invocable inv = (Invocable) engine;
Object returnValue = inv.invokeFunction("functionJsName", "functionJsParameter");
System.out.println(returnValue.toString());