如何自检freemarker模板以找出其使用的变量？

如何自检freemarker模板以找出其使用的变量？

我有相同的任务要从Java端的模板获取变量列表，除了使用反射之外，没有找到任何好的方法。我不确定是否有更好的方法来获取此数据，但这是我的方法：

public Set<String> referenceSet(Template template) throws TemplateModelException {    Set<String> result = new HashSet<>();    TemplateElement rootTreeNode = template.getRootTreeNode();    for (int i = 0; i < rootTreeNode.getChildCount(); i++) {        TemplateModel templateModel = rootTreeNode.getChildNodes().get(i);        if (!(templateModel instanceof StringModel)) { continue;        }        Object wrappedObject = ((StringModel) templateModel).getWrappedObject();        if (!"DollarVariable".equals(wrappedObject.getClass().getSimpleName())) { continue;        }        try { Object expression = getInternalState(wrappedObject, "expression"); switch (expression.getClass().getSimpleName()) {     case "Identifier":         result.add(getInternalState(expression, "name").toString());         break;     case "DefaultToexpression":         result.add(getInternalState(expression, "lho").toString());         break;     case "BuiltinVariable":         break;     default:         throw new IllegalStateException("Unable to introspect variable"); }        } catch (NoSuchFieldException | IllegalAccessException e) { throw new TemplateModelException("Unable to reflect template model");        }    }    return result;}private Object getInternalState(Object o, String fieldName) throws NoSuchFieldException, IllegalAccessException {    Field field = o.getClass().getDeclaredField(fieldName);    boolean wasAccessible = field.isAccessible();    try {        field.setAccessible(true);        return field.get(o);    } finally {        field.setAccessible(wasAccessible);    }}

我为演示模板自省所做的示例项目可以在github上找到：https
:
//github.com/SimY4/TemplatesPOC.git