java - Struts 2 与 Thymeleaf

Question

我想在我的网络应用程序中使用 Thymeleaf 作为模板引擎。我在Google上搜索了如何使用struts2配置Themeleaf，并找到了一些解决方案 plugin 。我已在我的应用程序中配置了插件，但无法使用插件呈现页面。相反，我收到错误:

org.thymeleaf.exceptions.TemplateInputException: Error resolving template "/WEB-INF/templates/hello.html", template might not exist or might not be accessible by any of the configured Template Resolvers
    org.thymeleaf.TemplateRepository.getTemplate(TemplateRepository.java:246)
    org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1104)
    org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1060)
    org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1011)
    org.thymeleaf.TemplateEngine.process(TemplateEngine.java:955)
    com.struts.custom.resulttype.plugin.ThemeleafResult.execute(ThemeleafResult.java:51)
    com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:374)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:278)
    org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:211)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:211)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:192)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
    org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:510)
    org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)

这是DefaultTemplateEngineProvider.java的实现

public class DefaultTemplateEngineProvider implements TemplateEngineProvider {
  // HTML5 is the future!
  private String templateMode = "HTML5";
  private String characterEncoding = "UTF-8";
  // This will convert "home" to "/WEB-INF/templates/home.html"
  private String prefix = "/WEB-INF/templates/";
  private String suffix = ".html";
  private boolean cacheable = true;

  // Default template cache TTL to 1 hour. If not set, entries would live in
  // cache until expelled by LRU.
  private Long cacheTtlMillis = 3600000L;

  private TemplateEngine templateEngine;

  /**
   * Configure settings from the struts.xml or struts.properties, using sensible
   * defaults if values are not provided.
   */
  public void configure() {
    ServletContextTemplateResolver templateResolver = new ServletContextTemplateResolver();
    templateResolver.setTemplateMode(templateMode);
    templateResolver.setCharacterEncoding(characterEncoding);
    templateResolver.setPrefix(prefix);
    templateResolver.setSuffix(suffix);
    templateResolver.setCacheable(cacheable);
    templateResolver.setCacheTTLMs(cacheTtlMillis);

    templateEngine = new TemplateEngine();
    templateEngine.setTemplateResolver(templateResolver);
    templateEngine.setMessageResolver(new StrutsMessageResolver());
  }


  public TemplateEngine get() {
    if (templateEngine == null) {
      configure();
    }

    return templateEngine;
  }

  @Inject(value = "struts.thymeleaf.templateMode", required = false)
  public void setTemplateMode(String templateMode) {
    this.templateMode = templateMode;
  }

  @Inject(value = "struts.thymeleaf.encoding", required = false)
  public void setCharacterEncoding(String characterEncoding) {
    this.characterEncoding = characterEncoding;
  }

  @Inject(value = "struts.thymeleaf.prefix", required = false)
  public void setPrefix(String prefix) {
    this.prefix = prefix;
  }

  @Inject(value = "struts.thymeleaf.suffix", required = false)
  public void setSuffix(String suffix) {
    this.suffix = suffix;
  }

  @Inject(value = "struts.thymeleaf.cacheable", required = false)
  public void setCacheable(String cacheable) {
    this.cacheable = Boolean.parseBoolean(cacheable);
  }

  @Inject(value = "struts.thymeleaf.cacheTtlMillis", required = false)
  public void setCacheTtlMillis(String cacheTtlMillis) {
    this.cacheTtlMillis = Long.parseLong(cacheTtlMillis);
  }
}

我已经编写了自定义结果集并配置了 Thymeleaf，如官方网站上所述。但得到同样的错误。

我的自定义结果类型是

public class ThymeleafResult implements Result {
  private String defaultEncoding = "UTF-8";
  private TemplateEngineProvider templateEngineProvider;
  private String templateName;

  /**
   * The result parameter name to set the name of the template to.
   * <p/>
   * IMPORTANT! Struts2 will look for this field reflectively to determine which
   * parameter is the default. This allows us to have a simplified result
   * configuration. Don't remove it!
   */
  public static final String DEFAULT_PARAM = "templateName";

  public ThymeleafResult() {
  }

  public ThymeleafResult(String templateName) {
    this.templateName = templateName;
  }


  public void execute(ActionInvocation actionInvocation) throws Exception {
    TemplateEngine templateEngine = templateEngineProvider.get();

    HttpServletRequest request = ServletActionContext.getRequest();
    HttpServletResponse response = ServletActionContext.getResponse();
    ServletContext servletContext = ServletActionContext.getServletContext();

    Object action = actionInvocation.getAction();

    StrutsContext context = new StrutsContext(request, response, servletContext, action);
    response.setContentType("text/html");
    response.setCharacterEncoding(defaultEncoding);
    System.out.println(templateName);
    templateEngine.process(templateName, context, response.getWriter());
  }

  @Inject(StrutsConstants.STRUTS_I18N_ENCODING)
  public void setDefaultEncoding(String defaultEncoding) {
    this.defaultEncoding = defaultEncoding;
  }

  @Inject
  public void setTemplateEngineProvider(TemplateEngineProvider templateEngineProvider) {
    this.templateEngineProvider = templateEngineProvider;
  }

  public void setTemplateName(String templateName) {
    this.templateName = templateName;
  }

struts.xml是

<struts>

    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />
    <constant name="struts.multipart.maxSize" value="1000000000" />
    <constant name="struts.custom.i18n.resources" value="ApplicationResources" />
     <bean type="org.codework.struts.plugins.thymeleaf.spi.TemplateEngineProvider" name="default" class="org.codework.struts.plugins.thymeleaf.spi.DefaultTemplateEngineProvider" />

    <package name="default" namespace="/" extends="struts-default">
        <result-types>
            <result-type name="thymeleaf" class="org.codework.struts.plugins.thymeleaf.ThymeleafResult"/>
        </result-types>
        <default-action-ref name="home"></default-action-ref>
        <action name="home" class="com.demo.example.Welcome">
             <result name="success" type="thymeleaf">/WEB-INF/templates/hello.html</result>
        </action>
    </package>
</struts>

Answer 1

我找到了解决方案:我在 struts.xml 中进行了错误的映射。

我刚刚更换

<result name="success" type="thymeleaf">/WEB-INF/templates/hello.html</result> 

与

<result name="success" type="thymeleaf">hello</result> 

并且成功了。