求给位大佬帮忙解决下，我用的项目的是 spring boot + mybatis puls + thymeleaf：
情况是这样的，我后台获取List<Map<String, Object>>这样的数据返回给前面thymeleaf模板。
到thymeleaf模板页面就报错了，如下：
[2018-05-11 13:44:35.337] ERROR freemarker.runtime [http-nio-8888-exec-1] Error executing FreeMarker template
freemarker.core.NonStringOrTemplateOutputException: For "${...}" content: Expected a string or something automatically convertible to string (number, date or boolean), or "template output" , but this has evaluated to a sequence (wrapper: f.t.SimpleSequence):
==> playList?if_exists [in template "start.html" at line 98, column 43]
----
FTL stack trace ("~" means nesting-related):
- Failed at: ${playList?if_exists} [in template "start.html" at line 98, column 41]
----
at freemarker.core.EvalUtil.coerceModelToTextualCommon(EvalUtil.java:511)
at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:389)
at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:358)
at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:100)
at freemarker.core.DollarVariable.accept(DollarVariable.java:63)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:336)
at freemarker.core.Environment.process(Environment.java:309)
at freemarker.template.Template.process(Template.java:384)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:396)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:309)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:257)
at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:165)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:314)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1325)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1069)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1008)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
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:52)
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:107)
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.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
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:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
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:107)
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:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
[2018-05-11 13:44:35.357] ERROR o.a.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] [http-nio-8888-exec-1] Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is freemarker.core.NonStringOrTemplateOutputException: For "${...}" content: Expected a string or something automatically convertible to string (number, date or boolean), or "template output" , but this has evaluated to a sequence (wrapper: f.t.SimpleSequence):
==> playList?if_exists [in template "start.html" at line 98, column 43]
----
FTL stack trace ("~" means nesting-related):
- Failed at: ${playList?if_exists} [in template "start.html" at line 98, column 41]
----] with root cause
freemarker.core.NonStringOrTemplateOutputException: For "${...}" content: Expected a string or something automatically convertible to string (number, date or boolean), or "template output" , but this has evaluated to a sequence (wrapper: f.t.SimpleSequence):
==> playList?if_exists [in template "start.html" at line 98, column 43]
----
FTL stack trace ("~" means nesting-related):
- Failed at: ${playList?if_exists} [in template "start.html" at line 98, column 41]
----
at freemarker.core.EvalUtil.coerceModelToTextualCommon(EvalUtil.java:511)
at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:389)
at freemarker.core.EvalUtil.coerceModelToStringOrMarkup(EvalUtil.java:358)
at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:100)
at freemarker.core.DollarVariable.accept(DollarVariable.java:63)
at freemarker.core.Environment.visit(Environment.java:330)
at freemarker.core.Environment.visit(Environment.java:336)
at freemarker.core.Environment.process(Environment.java:309)
at freemarker.template.Template.process(Template.java:384)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:396)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:309)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:257)
at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:165)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:314)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1325)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1069)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1008)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
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:52)
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:107)
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.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
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:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
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:107)
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:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
[2018-05-11 13:44:35.424] ERROR o.s.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration$SpelView [http-nio-8888-exec-1] Cannot render error page for request [/start] and exception [For "${...}" content: Expected a string or something automatically convertible to string (number, date or boolean), or "template output" , but this has evaluated to a sequence (wrapper: f.t.SimpleSequence):
==> playList?if_exists [in template "start.html" at line 98, column 43]
----
FTL stack trace ("~" means nesting-related):
- Failed at: ${playList?if_exists} [in template "start.html" at line 98, column 41]
----] as the response has already been committed. As a result, the response may have the wrong status code.
Controller层代码如下：
@RequestMapping("/start")
public ModelAndView getMusic(ModelAndView mv,HttpServletRequest request) {
try {
int pageNo = 0;
if(null != request.getParameter("pageNo")){
pageNo = Integer.valueOf(request.getParameter("pageNo").toString());
}
List<Map<String, Object>> listMusic = musicServiceInterface.getListMusic(pageNo);
mv.setViewName("start");
mv.addObject("src","file/"+musicName);
mv.addObject("playList",listMusic);
return mv;
} catch (Exception e) {
e.printStackTrace();
return mv;
}
}
}
thymeleaf模板页面如下：
<div id="play_list_wrap">
<div id="play_list" th:each="play : ${playList?if_exists}">
<span th:text="${play.name}">演示数据</span>
</div>
</div>
pom.xml代码:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--thymeleaf模板可以不严格-->
<dependency>
<groupId>net.sourceforge.nekohtml</groupId>
<artifactId>nekohtml</artifactId>
<version>1.9.22</version>
</dependency>
application.properties代码如下:
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.suffix=.html
spring.thymeleaf.mode=LEGACYHTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.servlet.content-type=text/html
spring.thymeleaf.cache=false
