js: 结果等于 eval(字符串)；
java: ScriptEngineManager factory = new ScriptEngineManager();
ScriptEngine engine = factory.getEngineByName("JavaScript");
结果等于 engine.eval(字符串);
简写：结果等于 (new ScriptEngineManager()).getEngineByName("JavaScript").eval(字符串);
原文：http://www.cnblogs.com/jetereting/p/5004807.html