Spring EL

https://docs.spring.io/spring-framework/reference/core/expressions/evaluation.html

更多的语法语义

    static class Simple {
        public List<Boolean> booleans = new ArrayList<>();
    }

    ExpressionParser parser = new SpelExpressionParser();
    Expression exp = parser.parseExpression("'Hello World'.concat('!')");
    String message = (String) exp.getValue();
    System.out.println(message);
    System.out.println(
        parser.parseExpression("'hello'.bytes.length").getValue()
    );

    Simple simple = new Simple();
    simple.booleans.add(false);
    EvaluationContext context = SimpleEvaluationContext.forReadOnlyDataBinding().build();

    parser.parseExpression("booleans[0]")
            .setValue(context,simple,"true");
    assert simple.booleans.get(0);