Tomcat10.0，用的是jakarta.*软件包而不是javax.*软件包

要用下图的包：

下载链接：

jakarta.servlet.jsp.jstl-2.0.0.jar

jakarta.servlet.jsp.jstl-api-2.0.0.jar

或用maven倚赖：j

<dependency>
    <groupId>org.glassfish.web</groupId>
    <artifactId>jakarta.servlet.jsp.jstl</artifactId>
    <version>2.0.0</version>
</dependency>

其他常用maven倚赖

<dependencies>
    <!--Servlet依赖-->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>

    <!--Jsp依赖-->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>javax.servlet.jsp-api</artifactId>
      <version>2.2.1</version>
      <scope>provided</scope>
    </dependency>
    <!--JSTL表达式依赖-->
    <dependency>
      <groupId>javax.servlet.jsp.jstl</groupId>
      <artifactId>javax.servlet.jsp.jstl-api</artifactId>
      <version>1.2.1</version>
    </dependency>

    <!--standard标签库-->
    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>

<dependency>
       <!--Mysql驱动包-->
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.25</version>
    </dependency>

<dependency>
       <!--无需main方法测试-->
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

  </dependencies>