Any script have to be compiled into intermediate code. : Script Engines « Development « Java Tutorial






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  3. Script Engines

This compilation takes a relatively large amount of CPU cycles.

With the Invocable interface you can save time by storing the compiled intermediate code for reuse.

import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;

public class InvocableDemo {

  public static void main(String[] args) throws Exception {
    ScriptEngineManager manager = new ScriptEngineManager();

    ScriptEngine engine = manager.getEngineByName("js");

    engine.eval("function add (a, b) {c = a + b; return c; }");
    Invocable jsInvoke = (Invocable) engine;

    Object result1 = jsInvoke.invokeFunction("add", new Object[] { 10, 5 });
    System.out.println(result1);

    Adder adder = jsInvoke.getInterface(Adder.class);
    int result2 = adder.add(10, 5);
    System.out.println(result2);
  }
}

interface Adder {
  int add(int a, int b);
}








6.42.Script Engines
6.42.1.Listing All Script Engines
6.42.2.List the script engines
6.42.3.Running Scripts with Java Script Engine
6.42.4.Execute Javascript script in a file
6.42.5.Variables bound through ScriptEngine
6.42.6.Catch ScriptException
6.42.7.Any script have to be compiled into intermediate code.
6.42.8.With Compilable interface you store the intermediate code of an entire script
6.42.9.Run JavaScript and get the result by using Java
6.42.10.Pass parameter to JavaScript through Java code
6.42.11.Get the value in JavaScript from Java Code by reference the variable name
6.42.12.Working with Compilable Scripts
6.42.13.Call a JavaScript function three times
6.42.14.Save the compiled JavaScript to CompiledScript object
6.42.15.Invoke an function
6.42.16.Using thread to run JavaScript by Java
6.42.17.Use jrunscript to execute JavaScript scripts
6.42.18.Get Script engine by extension name
6.42.19.Get a ScriptEngine by MIME type
6.42.20.Retrieving Script Engines by Name
6.42.21.Retrieving the Metadata of Script Engines
6.42.22.Retrieving the Supported File Extensions of a Scripting Engine
6.42.23.Retrieving the Supported Mime Types of a Scripting Engine
6.42.24.Retrieving the Registered Name of a Scripting Engine
6.42.25.Executing Scripts from Java Programs
6.42.26.Read and execute a script source file
6.42.27.Using Java Objects in JavaScript
6.42.28.Java Language Binding with JavaScript