Java实现字符串公式计算结果

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

public static void main(String[] args) {
    ScriptEngine js = new ScriptEngineManager().getEngineByName("JavaScript");
    try{
        System.out.println(js.eval("1+2"));
        System.out.println(js.eval("4 * (2/3)"));
        System.out.println(js.eval("3 + 2*4"));
        String o =  js.eval("3 + 2*4").toString();
        System.out.println(o);
    }catch (Exception e){
        System.out.println("异常");
    }
}