Thymeleaf中LocalDateTime类型格式化失效问题求助

• 环境：MySQL 8.0+，mysql-connector-java 8.0.12，JDBC驱动com.mysql.cj.jdbc.Driver，纯javax.servlet-api环境，Thymeleaf
• 现象：
  • JavaBean的orderDate属性为java.sql.Timestamp时，用#dates.format格式化正常
  • 改为java.time.LocalDateTime后，使用#temporals.format抛出TemplateProcessingException
• 相关代码：
  1. OrderBean类

  public class OrderBean {
      // ...其他属性
      private LocalDateTime orderDate;
      
      public LocalDateTime getOrderDate() {
          return orderDate;
      }
      
      public void setOrderDate(LocalDateTime orderDate) {
          this.orderDate = orderDate;
      }
  }
  

  2. 存入HttpSession的代码

  public String checkout(HttpSession session){
      // ...其他逻辑
      OrderBean orderBean = new OrderBean();
      LocalDateTime localDateTime = LocalDateTime.now();
      orderBean.setOrderDate(localDateTime);
      session.setAttribute("orderBean",orderBean);
      // ...其他逻辑
      return "cart/cart";
  }
  

  3. Thymeleaf模板代码

  <td th:text="${#temporals.format(orderBean.getOrderDate(),'yyyy-MM-dd HH:mm:ss')}"></td>
  

• 错误栈：

org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating OGNL expression: "#temporals.format(orderBean.getOrderDate(),'yyyy-MM-dd HH:mm:ss')" (template: "order/order" - line 48, col 19)
    at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:191)
    at org.thymeleaf.standard.expression.OGNLVariableExpressionEvaluator.evaluate(OGNLVariableExpressionEvaluator.java:95)
    at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:166)
    at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66)
    at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109)
    at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138)
    at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:144)
    at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74)
    at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95)
    at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633)
    at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314)
    at org.thymeleaf.engine.OpenElementTag.beHandled(OpenElementTag.java:205)
    at org.thymeleaf.engine.Model.process(Model.java:282)
    at org.thymeleaf.engine.Model.process(Model.java:290)
    at org.thymeleaf.engine.IteratedGatheringModelProcessable.processIterationModel(IteratedGatheringModelProcessable.java:367)
    at org.thymeleaf.engine.IteratedGatheringModelProcessable.process(IteratedGatheringModelProcessable.java:221)
    at org.thymeleaf.engine.ProcessorTemplateHandler.handleCloseElement(ProcessorTemplateHandler.java:1640)
    at org.thymeleaf.engine.CloseElementTag.beHandled(CloseElementTag.java:139)
    at org.thymeleaf.engine.TemplateModel.process(TemplateModel.java:136)

• 已尝试：引入thymeleaf-extras-java8time依赖，但问题依旧

纯Servlet环境下Thymeleaf不会自动注册Java8TimeDialect，需手动配置模板引擎时添加该方言：

1. 确保Maven依赖版本与Thymeleaf核心版本匹配：

<dependency>
    <groupId>org.thymeleaf.extras</groupId>
    <artifactId>thymeleaf-extras-java8time</artifactId>
    <version>3.1.2.RELEASE</version> <!-- 版本需和thymeleaf核心版本一致 -->
</dependency>

2. 在初始化Thymeleaf模板引擎的代码中添加方言：

import org.thymeleaf.TemplateEngine;
import org.thymeleaf.extras.java8time.dialect.Java8TimeDialect;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.templateresolver.ServletContextTemplateResolver;

// 示例：在ServletContextListener或初始化Servlet中配置
ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver(getServletContext());
templateResolver.setTemplateMode(TemplateMode.HTML);
templateResolver.setPrefix("/WEB-INF/templates/");
templateResolver.setSuffix(".html");

TemplateEngine templateEngine = new TemplateEngine();
templateEngine.setTemplateResolver(templateResolver);
// 关键步骤：注册Java8TimeDialect
templateEngine.addDialect(new Java8TimeDialect());

// 将模板引擎存入ServletContext供全局使用
getServletContext().setAttribute("templateEngine", templateEngine);

3. 验证模板表达式：
   完成配置后，模板中的#temporals.format即可正常处理LocalDateTime对象，完成格式化。

内容的提问来源于stack exchange，提问作者JavaWeb Noob