Java实现给程序自定义配置计算公式

使用 commons-jexl3 jar包

示例:

public static void main(String[] args){
    String expressionString = "1+2+3";
    JexlEngine jexlEngine = new JexlBuilder().create();
    JexlExpression jexlExpression = jexlEngine.createExpression(expressionString);
    Object evaluate = jexlExpression.evaluate(null);
    System.out.println(evaluate);
}

结果: 6

示例2:

来个复杂点的

    public static void main(String[] args){
        // String expressionString = "1+2+3";
        String expressionString = "100*10-(200+300)";
        JexlEngine jexlEngine = new JexlBuilder().create();
        JexlExpression jexlExpression = jexlEngine.createExpression(expressionString);
        Object evaluate = jexlExpression.evaluate(null);
        System.out.println(evaluate);
    }

结果: 500