Java计算字符串公式的方式解读

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-jexl3</artifactId>
    <version>3.1</version>
</dependency>

	@Test
    public void test03() {
        String expressionString = "27.0/10";
        JexlEngine jexlEngine = new JexlBuilder().create();
        JexlExpression jexlExpression = jexlEngine.createExpression(expressionString);
        Object evaluate = jexlExpression.evaluate(null);
        System.out.println(evaluate);
    }

	@Test
    public void test04() throws ScriptException {
        ScriptEngine jse = new ScriptEngineManager().getEngineByName("JavaScript");
        String strs = "27/10";
        System.out.println(jse.eval(strs));
    }

	@Test
    public void test04() throws ScriptException {
        ScriptEngine jse = new ScriptEngineManager().getEngineByName("JavaScript");
        String strs = "1+b";
        strs = strs.replace("b", "9");
        System.out.println(jse.eval(strs));
    }