eval

		ScriptEngineManager mgr = new ScriptEngineManager();
	    ScriptEngine engine = mgr.getEngineByName("JavaScript");
	    String foo1 = "1/3.0";
	    String foo2 = "40 - 0.12";
	    String foo3 = "2*0.3-0.1";
	    try {
	    	Double fooval1 = (Double)engine.eval(foo1);
	    	echoForm.name = fooval1.toString();
	    	Object fooval2 = engine.eval(foo2);
	    	Object fooval3 = engine.eval(foo3);

			System.out.println(fooval1);
			System.out.println(fooval2);
			System.out.println(fooval3);
		} catch (ScriptException e) {
			e.printStackTrace();
		}