Spring Boot将较旧版本的CSS文件应用于JSP

问题描述

我有一个Spring Boot项目,其中包含MainMenu.jsp,如下所示:

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
    <title>Test</title>
    <link rel="stylesheet" href="${pageContext.request.contextpath}/css/style.css">
    <Meta name="viewport" content="width=device-width,initial-scale=1.0">
    <div class="navheader">
        <h2>Test</h2>
        <c:if test="${pageContext.request.userPrincipal.name != null}">
            <form id="logoutForm" method="POST" action="${contextpath}/logout">
                <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>
            </form>

            <h2>Welcome ${pageContext.request.userPrincipal.name} | <a onclick="document.forms['logoutForm'].submit()">logout</a></h2>
        </c:if>
    </div>
</head>
<body>
    <ul>
        <li>Groups</li>
        <li>Frameworks</li>
    </ul>
</body>
</html>

我正在使用位于resources / static / css下的style.css文件,并且我的浏览器成功找到了它,因为它没有返回404错误。但是,我所做的任何更改都不会反映-它似乎正在使用旧版本的CSS。我怀疑它是使用style.css中的CSS,然后才更改了样式表的href

"/css/style.css""${pageContext.request.contextpath}/css/style.css"

如果路径正确,为什么不应用我的CSS?如果路径不正确,为什么使用较旧的版本,却没有提供404找不到文件

编辑: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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>samuelB</groupId>
    <artifactId>capripol</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>Capripol</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>MysqL</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

解决方法

浏览器根据设置缓存css文件,在开发设置中,您可以禁用浏览器中的缓存,以在网站加载时始终加载新文件。例如,如果您使用的是Chrome,则可以在“开发人员”工具的“网络”标签中勾选“禁用缓存”框。

enter image description here

对于生产系统,可以通过在CSS文件名中使用版本号来避免CSS缓存。

另请参阅:Browser Caching of CSS files