Spring Boot Thymeleaf模板解析异常求助：模板文件找不到

问题现象 #

整合Thymeleaf+Spring Context+flying-saucer-pdf生成PDF时，出现模板文件找不到的错误，错误日志如下：

2022-10-11T16:45:58.209+0700 ERROR [THYMELEAF][http-nio-8080-exec-2] Exception processing template "world-check-report": An error happened during template parsing (template: "applicationprocess/world-check-report.html")
org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "applicationprocess/world-check-report.html")
    at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:235) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:649) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) [thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1059) [thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1048) [thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]
    at com.aeon.webadmin.controller.AssessmentController.getWorldCheckStatus(AssessmentController.java:820) [classes/:1.3.5]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_333]
Caused by: java.io.FileNotFoundException: ClassLoader resource "applicationprocess/world-check-report.html" could not be resolved
at org.thymeleaf.templateresource.ClassLoaderTemplateResource.reader(ClassLoaderTemplateResource.java:130) ~[thymeleaf-3.0.11.RELEASE.jar:3.0.11.RELEASE]

相关代码 #

控制器代码 #

@PostMapping(value = "/world-check-info")
public ObjResponseEntity<AmlApplyLoan> getWorldCheckStatus(@RequestBody String aln_id) {
    try {
        HttpHeaders headers = new HttpHeaders();
        AssessmentController assessmentController = new AssessmentController();
        
        ClassLoaderTemplateResolver templateResolver = new ClassLoaderTemplateResolver();
        templateResolver.setPrefix("applicationprocess/");
        templateResolver.setSuffix(".html");
        templateResolver.setTemplateMode("XHTML");
        templateResolver.setCharacterEncoding("UTF-8");

        TemplateEngine templateEngine = new TemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);

        Context ctx = new Context();
        ctx.setVariable("message", "TESTING");
        
        // 解析时出错
        String htmtContent = templateEngine.process("world-check-report", ctx);
        
        return ObjResponseFactory.success();
        
    } catch (Exception e) {
        e.printStackTrace();
    }
    return ObjResponseFactory.fail();
}

模板文件代码 #

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
  </head>
<body>
    <div class="content-wrapper" style="padding-left: 120px; font-family: sans-serif;">
        <h2 class="page_title" th:text="${message}"></h2>
        <h2>CASE REPORT</h2>    
    </div>
</body>
</html>

解决方案 #

• 确认模板文件路径
  ClassLoaderTemplateResolver默认从classpath根目录加载资源，需确保模板文件放在src/main/resources/applicationprocess/下，编译后在target/classes/applicationprocess/中能找到world-check-report.html。若使用Thymeleaf默认路径，需将模板移至src/main/resources/templates/，并调整prefix为templates/applicationprocess/。

• 使用Spring自动配置的TemplateEngine
  Spring Boot已自动配置TemplateEngine和TemplateResolver，无需手动实例化，直接注入即可避免路径配置错误。修改后的控制器代码：

  @RestController
  public class AssessmentController {
      
      @Autowired
      private TemplateEngine templateEngine;
      
      @PostMapping(value = "/world-check-info")
      public ObjResponseEntity<AmlApplyLoan> getWorldCheckStatus(@RequestBody String aln_id) {
          try {
              Context ctx = new Context();
              ctx.setVariable("message", "TESTING");
              
              // 若模板在templates/applicationprocess/下，路径为applicationprocess/world-check-report
              String htmlContent = templateEngine.process("applicationprocess/world-check-report", ctx);
              
              return ObjResponseFactory.success();
              
          } catch (Exception e) {
              e.printStackTrace();
          }
          return ObjResponseFactory.fail();
      }
  }
  

• 修正手动配置的TemplateResolver
  若坚持手动配置，需确保prefix路径正确，可添加templateResolver.setCheckExistence(true);提前检查模板是否存在，便于调试：

  ClassLoaderTemplateResolver templateResolver = new ClassLoaderTemplateResolver();
  templateResolver.setPrefix("applicationprocess/");
  templateResolver.setSuffix(".html");
  templateResolver.setTemplateMode("XHTML");
  templateResolver.setCharacterEncoding("UTF-8");
  templateResolver.setCheckExistence(true); // 开启存在性检查
  

• 检查文件名一致性
  确保文件名world-check-report.html拼写、大小写与代码中的调用完全一致，Linux环境下文件名区分大小写。

内容的提问来源于stack exchange，提问作者11Strong