执行 FreeMarker 时，以下已评估为 null 或缺失

Question

我正在使用 FreeMarker（一个基于 Java 的免费模板引擎，最初专注于使用 MVC 软件架构生成动态网页）来生成一些 HTML 页面我有一个带有这段代码的 freemarker 模板：

 Dear ${user.firstname} ${user.surname},</h3>

我已经创建了这段代码来测试它：

public static void main(String[] args) throws IOException, TemplateException {


    class User {

        String firstname;

        public String getFirstname() {
            return firstname;
        }

        public void setFirstname(String firstname) {
            this.firstname = firstname;
        }





    }


    String templateName = "tdk_reminder_ext_body.ftl";

     final Map<String, Object> finalModel = new HashMap<>();

     User user = new User();

     user.setFirstname("firstname");

     finalModel.put("serverName", "local");
     finalModel.put("user", user);



    Configuration cfg = new Configuration(Configuration.getVersion());

    cfg.setDirectoryForTemplateLoading(new File("C:/Work/eclipse-tdk/templates/engine/"));
    cfg.setDefaultEncoding("UTF-8");
    cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);

    final freemarker.template.Template freemarkerTemplate = cfg.getTemplate(templateName);

    System.out.println (FreeMarkerTemplateUtils.processTemplateIntoString(freemarkerTemplate, finalModel));


}

但是当我运行程序时我得到了这个错误：

FTL stack trace ("~" means nesting-related):
    - Failed at: ${user.firstname}  [in template "tdk_reminder_ext_body.ftl" at line 34, column 38]
----

Answer 1

您的 class 必须是 public。 See the documentation.

public class User {

    String firstname;

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

}

执行 FreeMarker 时，以下已评估为 null 或缺失

The following has evaluated to null or missing when executing FreeMarker

java

freemarker