Calling java code from javascript.

JavaFromJavascript

import java.util.HashMap;
import java.util.Map;

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

public class TestMain {

	public static void main(String[] args) throws ScriptException {
		ScriptEngineManager factory = new ScriptEngineManager();
		ScriptEngine engine = factory.getEngineByName("JavaScript");
		
		Map<String, Object> bindings = new HashMap<String, Object>();

		bindings.put("test1", new Test1());
		bindings.put("test2", new Test2());
		
		for (String key : bindings.keySet()) {
			engine.put(key, bindings.get(key));
		}

		/* Print:
		 * Doing something in javascript here first
		 * Back in java code here: javascript value is bar 
		 */
		engine.eval("println('Doing something in javascript here first');"
				+ "var test = test2.apply('bar');"
				+ "test1.apply(test);");
	}
	
	public static class Test1 {
		public void apply(String s) {
			System.out.println("Back in java code here: " + s);
		}			
	}
	
	public static class Test2 {
		public String apply(String s) {
			return "javascript value is " + s;
		}			
	}
}