Spring Boot 添加jersey-mvc-freemarker依赖后内置tomcat启动不了解决方案

我在我的Spring Boot 项目的pom.xml中添加了jersey-mvc-freemarker依赖后，内置tomcat启动不了。

报错信息如下：

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:536) ~[spring-context-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at com.jiajian.JerseyTestDemoApplication.main(JerseyTestDemoApplication.java:10) [classes!/:0.0.1-SNAPSHOT]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
	at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
	at org.springframework.boot.loader.WarLauncher.main(WarLauncher.java:59) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:115) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:82) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:535) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:177) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	... 16 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
	at org.apache.catalina.startup.Tomcat.start(Tomcat.java:356) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
	at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:96) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
	... 21 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
	at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:791) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
	... 23 common frames omitted

原因是因为jersey-mvc-freemarker中引用了

<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>

然而内置tomcat依赖中也有此包，虽然没有此依赖，由于自己引入了依赖，导致spring-boot的内置tomcat启动冲突报错。

解决方案，在jersey-mvc-freemarker排除servlet-api即可

<dependency>
    <groupId>org.glassfish.jersey.ext</groupId>
    <artifactId>jersey-mvc-freemarker</artifactId>
    <version>2.23.2</version>
    <exclusions>
        <exclusion>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
        </exclusion>
    </exclusions>
</dependency>