thymeleaf 不同的行为（通过数据库和 resttemplate）
thymeleaf different behavior (via database and resttemplate)
各位。
我有两个应用程序。
第一个是 CRUD spring 引导 JPA web mvc 应用程序。
它适用于这些代码。 （通过存储库数据库）
@RequestMapping(value = { "/newUser" }, method = RequestMethod.GET)
public String newUser(ModelMap model) {
User user = new User();
List<UserProfile> roles = userProfileRepository.findAll();
model.addAttribute("user", user);
model.addAttribute("allRoles", roles);
return "registration";
}
@RequestMapping(value = { "/newUser" }, method = RequestMethod.POST)
public String saveUser(@Valid User user, BindingResult result,
ModelMap model) {
if (result.hasErrors()) {
List<UserProfile> roles = userProfileRepository.findAll();
model.addAttribute("allRoles", roles);
model.addAttribute("user", user);
return "registration";
}
userRepository.save(user);
return "registrationsuccess";
}
registration.html 的一部分是
<select class="form-control input-sm" id="userProfiles" name="userProfiles" multiple="multiple" th:required="true">
<option th:each="role : ${allRoles}"
th:value="${{role}}"
th:text="${role.type}"
th:selected="${role.id == 1}"
>Role
</option>
</select>
上面的代码工作正常。
第二个应用是基于resttemplate的spring boot
@RequestMapping(value = { "/newUser" }, method = RequestMethod.GET)
public String newUser(ModelMap model) {
User user = new User();
RestTemplate restTemplate = new RestTemplate();
List<UserProfile> userProfiles = Arrays.asList(restTemplate.getForObject("http://localhost:8080/api/roles", UserProfile[].class));
ArrayList<UserProfile> roles = new ArrayList<>(userProfiles);
model.addAttribute("user", user);
model.addAttribute("allRoles", roles);
return "registration";
}
@RequestMapping(value = { "/newUser" }, method = RequestMethod.POST)
public String saveUser(@Valid User user, BindingResult result,
ModelMap model) {
if (result.hasErrors()) {
RestTemplate restTemplate = new RestTemplate();
List<UserProfile> userProfiles = Arrays.asList(restTemplate.getForObject("http://localhost:8080/api/roles", UserProfile[].class));
ArrayList<UserProfile> roles = new ArrayList<>(userProfiles);
model.addAttribute("allRoles", roles);
model.addAttribute("user", user);
return "registration";
}
RestTemplate restTemplate = new RestTemplate();
restTemplate.postForObject("http://localhost:8080/api/users", user, User.class);
return "registrationsuccess";
}
多个 select 表单与第一个应用程序相同（相同）
但是第二个应用在调用 registration.html 时抛出异常
There was an unexpected error (type=Internal Server Error, status=500).
An error happened during template parsing (template: "class path resource [templates/registration.html]")
org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "class path resource [templates/registration.html]")
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:241)
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100)
at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666)
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098)
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072)
at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362)
at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1371)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1117)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1056)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.attoparser.ParseException: Exception evaluating SpringEL expression: "role" (template: "registration" - line 60, col 37)
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:393)
at org.attoparser.MarkupParser.parse(MarkupParser.java:257)
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:230)
... 52 more
Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression: "role" (template: "registration" - line 60, col 37)
at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:290)
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$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633)
at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314)
at org.thymeleaf.engine.OpenElementTag.beHandled(OpenElementTag.java:205)
at org.thymeleaf.engine.Model.process(Model.java:282)
at org.thymeleaf.engine.Model.process(Model.java:290)
at org.thymeleaf.engine.IteratedGatheringModelProcessable.processIterationModel(IteratedGatheringModelProcessable.java:367)
at org.thymeleaf.engine.IteratedGatheringModelProcessable.process(IteratedGatheringModelProcessable.java:221)
at org.thymeleaf.engine.ProcessorTemplateHandler.handleCloseElement(ProcessorTemplateHandler.java:1640)
at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleCloseElementEnd(TemplateHandlerAdapterMarkupHandler.java:388)
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleCloseElementEnd(InlinedOutputExpressionMarkupHandler.java:322)
at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleCloseElementEnd(OutputExpressionInlinePreProcessorHandler.java:220)
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleCloseElementEnd(InlinedOutputExpressionMarkupHandler.java:164)
at org.attoparser.HtmlElement.handleCloseElementEnd(HtmlElement.java:169)
at org.attoparser.HtmlMarkupHandler.handleCloseElementEnd(HtmlMarkupHandler.java:412)
at org.attoparser.MarkupEventProcessorHandler.handleCloseElementEnd(MarkupEventProcessorHandler.java:473)
at org.attoparser.ParsingElementMarkupUtil.parseCloseElement(ParsingElementMarkupUtil.java:201)
at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:725)
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301)
... 54 more
Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1001E: Type conversion problem, cannot convert from com.naranov.rest_client.model.UserProfile to java.lang.String
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:75)
at org.springframework.expression.common.ExpressionUtils.convertTypedValue(ExpressionUtils.java:57)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:367)
at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:277)
... 79 more
Caused by: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [com.naranov.rest_client.model.UserProfile] to type [java.lang.String]
at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:321)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:194)
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:70)
... 82 more
PS。我已经通过 PostMan 测试了所有方法（PUT、GET、DELETE 和 POST）。它工作正常。
我不明白百里香的不同行为..
如堆栈跟踪中所述，从 th:value="${{role}}" 中删除双括号语法。
双括号应用转换服务，通常用于日期等内容。这在 docs.
的数据转换部分
我刚刚实现了 org.springframework.core.convert.converter.Converter;
@Component
public class RoleToUserProfileConverter implements Converter<Object, UserProfile>{
@Autowired
UserProfileService userProfileService;
public UserProfile convert(Object element) {
Integer id = Integer.parseInt((String)element);
return userProfileService.findById(id);
}
}
并稍微修改了这个表格
<select class="form-control input-sm" id="userProfiles" name="userProfiles" multiple="multiple" th:required="true">
<option th:each="role : ${allRoles}"
th:value="${role.id}"
th:text="${role.type}"
th:selected="${role.id == 1}"
>Role
</option>
</select>
现在，thymeleaf 将值转换为对象。
谢谢大家！
各位。 我有两个应用程序。 第一个是 CRUD spring 引导 JPA web mvc 应用程序。 它适用于这些代码。 （通过存储库数据库）
@RequestMapping(value = { "/newUser" }, method = RequestMethod.GET)
public String newUser(ModelMap model) {
User user = new User();
List<UserProfile> roles = userProfileRepository.findAll();
model.addAttribute("user", user);
model.addAttribute("allRoles", roles);
return "registration";
}
@RequestMapping(value = { "/newUser" }, method = RequestMethod.POST)
public String saveUser(@Valid User user, BindingResult result,
ModelMap model) {
if (result.hasErrors()) {
List<UserProfile> roles = userProfileRepository.findAll();
model.addAttribute("allRoles", roles);
model.addAttribute("user", user);
return "registration";
}
userRepository.save(user);
return "registrationsuccess";
}
registration.html 的一部分是
<select class="form-control input-sm" id="userProfiles" name="userProfiles" multiple="multiple" th:required="true">
<option th:each="role : ${allRoles}"
th:value="${{role}}"
th:text="${role.type}"
th:selected="${role.id == 1}"
>Role
</option>
</select>
上面的代码工作正常。
第二个应用是基于resttemplate的spring boot
@RequestMapping(value = { "/newUser" }, method = RequestMethod.GET)
public String newUser(ModelMap model) {
User user = new User();
RestTemplate restTemplate = new RestTemplate();
List<UserProfile> userProfiles = Arrays.asList(restTemplate.getForObject("http://localhost:8080/api/roles", UserProfile[].class));
ArrayList<UserProfile> roles = new ArrayList<>(userProfiles);
model.addAttribute("user", user);
model.addAttribute("allRoles", roles);
return "registration";
}
@RequestMapping(value = { "/newUser" }, method = RequestMethod.POST)
public String saveUser(@Valid User user, BindingResult result,
ModelMap model) {
if (result.hasErrors()) {
RestTemplate restTemplate = new RestTemplate();
List<UserProfile> userProfiles = Arrays.asList(restTemplate.getForObject("http://localhost:8080/api/roles", UserProfile[].class));
ArrayList<UserProfile> roles = new ArrayList<>(userProfiles);
model.addAttribute("allRoles", roles);
model.addAttribute("user", user);
return "registration";
}
RestTemplate restTemplate = new RestTemplate();
restTemplate.postForObject("http://localhost:8080/api/users", user, User.class);
return "registrationsuccess";
}
多个 select 表单与第一个应用程序相同（相同） 但是第二个应用在调用 registration.html 时抛出异常
There was an unexpected error (type=Internal Server Error, status=500).
An error happened during template parsing (template: "class path resource [templates/registration.html]")
org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "class path resource [templates/registration.html]")
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:241)
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100)
at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666)
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098)
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072)
at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362)
at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1371)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1117)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1056)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.attoparser.ParseException: Exception evaluating SpringEL expression: "role" (template: "registration" - line 60, col 37)
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:393)
at org.attoparser.MarkupParser.parse(MarkupParser.java:257)
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:230)
... 52 more
Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression: "role" (template: "registration" - line 60, col 37)
at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:290)
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$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633)
at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314)
at org.thymeleaf.engine.OpenElementTag.beHandled(OpenElementTag.java:205)
at org.thymeleaf.engine.Model.process(Model.java:282)
at org.thymeleaf.engine.Model.process(Model.java:290)
at org.thymeleaf.engine.IteratedGatheringModelProcessable.processIterationModel(IteratedGatheringModelProcessable.java:367)
at org.thymeleaf.engine.IteratedGatheringModelProcessable.process(IteratedGatheringModelProcessable.java:221)
at org.thymeleaf.engine.ProcessorTemplateHandler.handleCloseElement(ProcessorTemplateHandler.java:1640)
at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleCloseElementEnd(TemplateHandlerAdapterMarkupHandler.java:388)
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleCloseElementEnd(InlinedOutputExpressionMarkupHandler.java:322)
at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleCloseElementEnd(OutputExpressionInlinePreProcessorHandler.java:220)
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleCloseElementEnd(InlinedOutputExpressionMarkupHandler.java:164)
at org.attoparser.HtmlElement.handleCloseElementEnd(HtmlElement.java:169)
at org.attoparser.HtmlMarkupHandler.handleCloseElementEnd(HtmlMarkupHandler.java:412)
at org.attoparser.MarkupEventProcessorHandler.handleCloseElementEnd(MarkupEventProcessorHandler.java:473)
at org.attoparser.ParsingElementMarkupUtil.parseCloseElement(ParsingElementMarkupUtil.java:201)
at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:725)
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301)
... 54 more
Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1001E: Type conversion problem, cannot convert from com.naranov.rest_client.model.UserProfile to java.lang.String
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:75)
at org.springframework.expression.common.ExpressionUtils.convertTypedValue(ExpressionUtils.java:57)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:367)
at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:277)
... 79 more
Caused by: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [com.naranov.rest_client.model.UserProfile] to type [java.lang.String]
at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:321)
at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:194)
at org.springframework.expression.spel.support.StandardTypeConverter.convertValue(StandardTypeConverter.java:70)
... 82 more
PS。我已经通过 PostMan 测试了所有方法（PUT、GET、DELETE 和 POST）。它工作正常。 我不明白百里香的不同行为..
如堆栈跟踪中所述，从 th:value="${{role}}" 中删除双括号语法。
双括号应用转换服务，通常用于日期等内容。这在 docs.
的数据转换部分我刚刚实现了 org.springframework.core.convert.converter.Converter;
@Component
public class RoleToUserProfileConverter implements Converter<Object, UserProfile>{
@Autowired
UserProfileService userProfileService;
public UserProfile convert(Object element) {
Integer id = Integer.parseInt((String)element);
return userProfileService.findById(id);
}
}
并稍微修改了这个表格
<select class="form-control input-sm" id="userProfiles" name="userProfiles" multiple="multiple" th:required="true">
<option th:each="role : ${allRoles}"
th:value="${role.id}"
th:text="${role.type}"
th:selected="${role.id == 1}"
>Role
</option>
</select>
现在，thymeleaf 将值转换为对象。 谢谢大家！