Vaadin Servlet conflict from 7.7.1

Question

My project is a spring boot and vaadin project. The spring boot is 1.4.1 with tomcat 8.5.5

It work as well until Vaadin 7.7.0

After I migration Vaadin to any version after 7.7.0 (1,2,3 for now), it fail to start and throw a exception

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

After researching from Google I found that it is a method from Servlet 3.1. However, a release note in Vaadin 7.7.1 said

#20190  Servlet <=3.0.1 requirement strictness

I read the issue but I cannot found useful information.

Here is the pom file relative to this problem

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-spring-boot-starter</artifactId>
    <version>1.0.2</version>
</dependency>
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-client</artifactId>
</dependency>
<dependency>
    <groupId>com.vaadin</groupId>
    <artifactId>vaadin-push</artifactId>
</dependency>

Also with full error trace stack.

2016-10-18 00:25:17.634  INFO 163628 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.5
2016-10-18 00:25:17.724 ERROR 163628 --- [cat-startStop-1] org.apache.catalina.core.ContainerBase   : A child container failed during start

java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]
        at java.util.concurrent.FutureTask.report(FutureTask.java:122) [na:1.8.0_73]
        at java.util.concurrent.FutureTask.get(FutureTask.java:192) [na:1.8.0_73]
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:911) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:890) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1403) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1393) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_73]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_73]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_73]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_73]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 6 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [Pipeline[StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5099) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 6 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.authenticator.NonLoginAuthenticator[]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardPipeline.startInternal(StandardPipeline.java:170) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 8 common frames omitted
Caused by: java.lang.NoSuchMethodError: javax.servlet.ServletContext.getVirtualServerName()Ljava/lang/String;
        at org.apache.catalina.authenticator.AuthenticatorBase.startInternal(AuthenticatorBase.java:1122) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 10 common frames omitted

2016-10-18 00:25:17.724 ERROR 163628 --- [           main] org.apache.catalina.core.ContainerBase   : A child container failed during start

java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]
        at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_73]
        at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_73]
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:911) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:791) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:356) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:96) [spring-boot-1.4.1.RELEASE.jar:1.4.1.
ELEASE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:82) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELE
SE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:535)
[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:177) [spri
g-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) [spring-boot-1.4.1.RELEAS
.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:535) [spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at xx.xxxxx.xx.xxxxApplication.main(KmatrixAutomatedReportSystemApplication.java:32) [classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_73]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_73]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_73]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_73]
        at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:506) [spring-boot-maven-plugin-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_73]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1403) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1393) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_73]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) ~[na:1.8.0_73]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) ~[na:1.8.0_73]
        ... 1 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:890) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 6 common frames omitted

2016-10-18 00:25:17.724  WARN 163628 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh atte
pt: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletConta
nerException: Unable to start embedded Tomcat
2016-10-18 00:25:17.734 ERROR 163628 --- [           main] o.s.boot.SpringApplication               : Application startup failed

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainer
xception: Unable to start embedded Tomcat
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:535) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at xx.xxxxx.xx.xxxxApplication.main(KmatrixAutomatedReportSystemApplication.java:32) [classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_73]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_73]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_73]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_73]
        at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:506) [spring-boot-maven-plugin-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_73]
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-1.4.1.RELEASE.jar:1.4.
.RELEASE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:82) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.REL
ASE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:535)
~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:177) ~[spr
ng-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.4.1.RELEA
E.jar:1.4.1.RELEASE]
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
        ... 14 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-8.5.5.jar:8.5.5]
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:356) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:96) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1
RELEASE]
        ... 19 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-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:791) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 21 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 23 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.5.jar:8.5.5]
        ... 25 common frames omitted

[WARNING]
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:506)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServl
tContainerException: Unable to start embedded Tomcat
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:535)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175)
        at hk.kmatrix.ce.KmatrixAutomatedReportSystemApplication.main(KmatrixAutomatedReportSystemApplication.java:32)
        ... 6 more
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)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:82)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:535)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:177)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134)
        ... 14 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:356)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:96)
        ... 19 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:791)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 21 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 23 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 25 more

I'm not sure that issue you mentioned is relevant unless you run in an OSGi environment. If you run `mvn dependency:tree` can you spot multiple servlet api versions in the log? — Morfic, Oct 17 '16 at 14:35
@Morfic forgot to mention that, I already check `mvn dependency:tree`, the servlet version is 3.1 — Roy, Oct 17 '16 at 14:49
I saw your pom which inherits it from boot with version 3.1.0 and also sets it as `provided`. What I was asking is whether you can see multiple versions somehow. Also, is you tomcat installation hardened or changed in any way? For example if you download a new copy of it and try running your app with it, do you get the same error? — Morfic, Oct 17 '16 at 15:01
@Morfic Sorry for the misleading reply. I mean I just check all dependency it is the only place I found. I use the spring boot embedded tomcat. I also try spring boot 1.3.8 which run tomcat 8.0, and as well as jetty. However, nothing change. — Roy, Oct 17 '16 at 15:13
Can you share your servlet configuration and the full stacktrace? — Morfic, Oct 17 '16 at 16:20
@Morfic The full stacktrace append at the end of question. There is no manually servlet config for this project. I found that there is only a jetty 8 work for me. However, it comes from the probleam for this question. [link](http://stackoverflow.com/questions/39158193/spring-boot-with-vaadin-run-jetty-even-though-i-use-tomcat) — Roy, Oct 17 '16 at 16:30
Do you have any other vaadin (eg `vaadin-client-compiler`) or otherwise dependencies in your pom. Can you share it entirely? This is definitely a classpath issue, most likely a clash between some transitive servlet-api versions. — Morfic, Oct 17 '16 at 17:14
@Morfic I remove `vaadin-client-compiler` since the issue I mention in the other problem. This is all the dependency I use for this project. — Roy, Oct 18 '16 at 02:04
http://stackoverflow.com/q/24080541/206466 says it's a problem with `ServletContext` duplicates found `[Loaded javax.servlet.ServletContext from file:/Users/calebcushing/.m2/repository/com/vaadin/external/gwt/gwt-user/2.7.0.vaadin4/gwt-user-2.7.0.vaadin4.jar]` — xenoterracide, Dec 16 '16 at 17:06
https://github.com/vaadin/framework/issues/8026 I have opened this issue — xenoterracide, Dec 16 '16 at 17:52
@xenoterracide thanks for your submission. BTW, the solution I use until now is deploy with tomcat but debug with a standalone app — Roy, Dec 31 '16 at 15:33
@Roy turns out `gwt-user` is only required at compile time so I excluded the dependency as it was being pulled in transiently (as provided), and was only needed by our widgetset build. Our development (embedded server) start class lives in test, and so provided classes are available on a test classpath. — xenoterracide, Jan 01 '17 at 17:51

Vaadin Servlet conflict from 7.7.1

0 Answers0