Hey there! Let's get this sorted out for you. First, let's clear up a common misconception: that javax.servlet.http.HttpServlet error isn't a Tomcat configuration problem—it's because your project doesn't have the Servlet API dependency included in its build path. Let's fix that first, then set up the Maven Tomcat plugin properly.

Step 1: Add the Servlet API Dependency to pom.xml #

Maven doesn't include the Servlet API by default because it's provided by the servlet container (like Tomcat) at runtime. So we need to add it with a provided scope (this tells Maven not to package it into your WAR, since Tomcat will supply it).

Open your project's pom.xml and add this inside the <dependencies> block:

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version> <!-- Match this to your Tomcat version: Tomcat 9 uses 4.0.x, Tomcat 8 uses 3.1.x, Tomcat 7 uses 3.0.x -->
    <scope>provided</scope>
</dependency>

After adding this, refresh your Maven project (in IDEA, click the "Maven" tab and hit the refresh button; in Eclipse, right-click the project > Maven > Update Project). The error in your index.jsp should disappear immediately.

Step 2: Configure the Maven Tomcat Plugin #

Now let's set up the Tomcat plugin so you can run your project directly via Maven. Add this inside the <build><plugins> block of your pom.xml:

<plugin>
    <groupId>org.apache.tomcat.maven</groupId>
    <artifactId>tomcat7-maven-plugin</artifactId> <!-- Use tomcat8-maven-plugin or tomcat9-maven-plugin if you need newer versions -->
    <version>2.2</version>
    <configuration>
        <port>8080</port> <!-- Customize the port if 8080 is in use -->
        <path>/</path> <!-- Set the base URL path (e.g., /myapp would make your app accessible at http://localhost:8080/myapp) -->
        <uriEncoding>UTF-8</uriEncoding> <!-- Fixes potential Chinese character encoding issues -->
    </configuration>
</plugin>

Step 3: Run Your Project with Maven Tomcat #

To start the server, open your terminal (or use your IDE's built-in terminal), navigate to your project's root directory, and run:

mvn tomcat7:run

If you used the tomcat8 or tomcat9 plugin, replace tomcat7 with tomcat8 or tomcat9 accordingly. Once the server starts, you can access your app at http://localhost:8080 (or whatever port/path you configured).

Quick Notes #

• Make sure the plugin version matches your Tomcat version preference—you can check the latest plugin versions on Maven Central if needed.
• If you're using a newer Jakarta EE version (instead of javax.servlet), use jakarta.servlet:jakarta.servlet-api as the dependency group/artifactId instead.

内容的提问来源于stack exchange，提问作者Terry Yue