2020/10/6

一

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

public class ExpressionCalculate {
    public static void main(String[] args) {
    	String n=new String();
    	n= "6*5*(5+6)";
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        ScriptEngine scriptEngine = scriptEngineManager.getEngineByName("nashorn");
        String expression = n;

        try {
            String result = String.valueOf(scriptEngine.eval(expression));
            System.out.println(result);
        } catch (ScriptException e) {
            e.printStackTrace();
        }
    }
}

 使用该包可以实现四则运算

二.对括号的压栈

三.javaweb