SpringBoot使用外置Tomcat的操作步骤

<?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>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.5.6</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>

  <groupId>com.qcby</groupId>
  <artifactId>springboottomcat</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging><!-- 注意这里是war的打包方式 -->

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>8</maven.compiler.source>
    <maven.compiler.target>8</maven.compiler.target>
  </properties>

  <dependencies>
    <!-- Web依赖 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
      <!-- 排除内置的Tomcat依赖 -->
      <exclusions>
        <exclusion>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <!-- 将嵌入式的Tomcat指定为provided -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring‐boot‐starter‐tomcat</artifactId>
      <scope>provided</scope>
    </dependency>

    <!-- 添加Servlet API依赖（provided表示打包时不包含，由外置容器提供） -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>

  <!-- Spring Boot Maven插件，这是生成可执行jar的关键 -->
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

package com.qcby.springBootTomcat;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
public class springBootTomcat extends SpringBootServletInitializer{
    // 内置容器启动入口（保留不影响，外置容器不会走这个方法）
    public static void main(String[] args) {
        SpringApplication.run(springBootTomcat.class,args);
    }

    // 外置容器启动入口：重写configure方法
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(springBootTomcat.class);
    }
}

@RestController
public class HelloController {
    // 测试接口
    @GetMapping("/hello")
    public String hello() {
        return "Hello, Tomcat!";
    }
}