使用外部容器运行spring-boot项目：不使用spring-boot内置容器让spring-boot项目运行在外部tomcat容器中

前言：本项目基于maven构建

spring-boot项目可以快速构建web应用，其内置的tomcat容器也十分方便我们的测试运行；

spring-boot项目需要部署在外部容器中的时候，spring-boot导出的war包无法再外部容器（tomcat）中运行或运行报错，本章就是详细讲解如何解决这个问题

1、pom.xml一览

<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>项目名称自行自行定义</groupId>
	<artifactId>项目名称自行定义</artifactId>
	<version>1.1.2-SNAPSHOT</version>
	<packaging>war</packaging>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.4.0.RELEASE</version>
	</parent>
	<dependencies>
		<!-- spring-boot web -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
			<!-- 排除内置容器，排除内置容器导出成war包可以让外部容器运行spring-boot项目-->
			<exclusions>
				<exclusion>
					<groupId>org.springframework.boot</groupId>
					<artifactId>spring-boot-starter-tomcat</artifactId>
				</exclusion>
			</exclusions>
			 
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
		</dependency>
		<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
		</dependency>

		<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-pool2 -->
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-pool2</artifactId>
		</dependency>

		<dependency>
			<groupId>org.json</groupId>
			<artifactId>json</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>com.jayway.jsonpath</groupId>
			<artifactId>json-path</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
	
	<!-- Package as an executable jar -->
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
	<repositories>
		<repository>
			<id>spring-releases</id>
			<url>https://repo.spring.io/libs-release</url>
		</repository>
	</repositories>
	<pluginRepositories>
		<pluginRepository>
			<id>spring-releases</id>
			<url>https://repo.spring.io/libs-release</url>
		</pluginRepository>
	</pluginRepositories>
</project>

2、排除org.springframework.boot依赖中的tomcat内置容器

注意：只有排除内置容器，才能让外部容器运行spring-boot项目

org.springframework.boot依赖中的排除项，测试时不要排除内置容器，会导致springboot无法测试运行，导出war包时再加上该项即可

<!-- spring-boot web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<!-- 排除内置容器，排除内置容器导出成war包可以让外部容器运行spring-boot项目-->
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>

3、实现SpringBootServletInitializer接口

spring-boot入口类必须实现SpringBootServletInitializer接口的configure方法才能让外部容器运行spring-boot项目

注意：SpringBootServletInitializer接口需要依赖 javax.servlet

package cn.eguid.Run;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.context.annotation.ComponentScan;

import cc.eguid.livepush.PushManager;
import cc.eguid.livepush.PushManagerImpl;
import cn.eguid.livePushServer.redisManager.RedisMQHandler;

@SpringBootApplication
// 开启通用注解扫描
@ComponentScan
public class Application extends SpringBootServletInitializer {
	/**
	 * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行
	 */
	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
		builder.sources(this.getClass());
		return super.configure(builder);
	}
	
	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
		
	}
}

总结：

外部容器运行spring-boot项目，只需要在原项目上做两件事

1、在pom.xml中排除org.springframework.boot的内置tomcat容器

2、spring-boot入口实现SpringBootServletInitializer接口

补充：SpringBootServletInitializer接口依赖javax.servlet包，需要在pom.xml中引入该包