我有一台带有Thymleaf页面的Spring Boot服务器。当我不使用style.css时，效果很好。但是，当我链接样式表（<link rel="stylesheet" type="text/css" href="../static/css/style.css" th:href="@{/css/style.css}"/>）并尝试访问该页面时，样式表未链接，并且服务器删除了堆栈跟踪（请参见下文）。
项目结构：
├─ pom.xml
├─ src
│ ├─ main
│ │ ├── java
│ │ │ └── com.alexesmet.example
│ │ │ ├── Application.java
│ │ │ └── controller
│ │ │ └── RootController.java
│ │ └── resources
│ │ ├── application.properties
│ │ ├── static
│ │ │ └── css
│ │ │ └── style.css
│ │ └── templates
│ │ └── index.html
│ └─ test
│ └── java
我的pom.xml：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.alexesmet.example</groupId>
<artifactId>webshop</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.1.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>5.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.4</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
我的index.html：
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Web Shop</title>
<link rel="stylesheet" type="text/css" href="../static/css/style.css" th:href="@{/css/style.css}"/>
</head>
<body>
<p th:text="thymleaf">html</p>
</body>
</html>
我的控制器：
@Controller
public class RootController {
@RequestMapping("/")
public String index(){
return "index";
}
}
当尝试访问localhost:8080上的页面时，浏览器会显示以下信息：
<html lang="en"><head>
<meta charset="UTF-8">
<title>Web Shop</title>
<link rel="stylesheet" type="text/css" href="/css/style.css">
</head>
<body>
<p>thymleaf</p>
</body>
</html>
，Spring Boot控制台显示以下内容：
2019-01-23 15:16:17.966 ERROR 5035 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException: null
at org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1231) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1014) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.28.jar:8.5.28]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.4.RELEASE.jar:5.0.4.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.4.RELEASE.jar:5.0.4.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.28.jar:8.5.28]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.28.jar:8.5.28]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) [na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.28.jar:8.5.28]
at java.base/java.lang.Thread.run(Thread.java:844) [na:na]
请记住，只有在我将这一行添加到index.html的头部时，这种情况才会发生。
<link rel="stylesheet" type="text/css" href="../static/css/style.css" th:href="@{/css/style.css}"/>
为什么？ 我该如何解决？
P.S。为避免其他问题，我在GitHub上有这个项目。
更新： 我更新到Spring Boot版本2.1.2RELEASE（如您所见，我是2.0.0用户）。控制台输出已更改：
2019-01-23 18:04:46.707 WARN 21852 --- [nio-8080-exec-2] o.s.web.servlet.PageNotFound : No mapping for GET /css/style.css
2019-01-23 18:04:46.757 ERROR 21852 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] threw exception
java.lang.NoSuchMethodError: org.springframework.http.MediaType.equalsTypeAndSubtype(Lorg/springframework/util/MimeType;)Z
at org.springframework.http.converter.AbstractHttpMessageConverter.canWrite(AbstractHttpMessageConverter.java:180) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.canWrite(AbstractJackson2HttpMessageConverter.java:172) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.canWrite(AbstractGenericHttpMessageConverter.java:76) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:278) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:223) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at... (omitted)
2019-01-23 18:04:46.758 ERROR 21852 --- [nio-8080-exec-2] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]
org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.NoSuchMethodError: org.springframework.http.MediaType.equalsTypeAndSubtype(Lorg/springframework/util/MimeType;)Z
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1053) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at... (omitted)
答案 0 :(得分：1)
删除@EnableWebMvc批注，可能会加载CSS。
我在成功道路上所做的事情：
pom.xml。堆栈跟踪变得更具可读性。@EnableWebMvc已过时。 我删除了它。有效。