由于缺少 EmbeddedServletContainerFactory bean，Spring Boot 无法启动 EmbeddedWebApplicationContext

Question

I have a spring boot web application which I'm trying to get running as a standalone application with Tomcat embedded rather than using a container.

I'm developing in IntelliJ, and I've setup a run configuration as Spring Boot and the application is working running from IntelliJ.

I've created an artifact in IntelliJ to create a JAR file and I've set it to include all of the dependencies from Maven.

However, when I run the application I get an error;

14:52:19.303 [main] ERROR o.s.boot.SpringApplication - Application startup failed
org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:133) ~[NatLocApp.jar:na]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:531) ~[NatLocApp.jar:na]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[NatLocApp.jar:na]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) [NatLocApp.jar:na]
    at org.springframework.boot.SpringApplication.doRun(SpringApplication.java:347) [NatLocApp.jar:na]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:295) [NatLocApp.jar:na]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1112) [NatLocApp.jar:na]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1101) [NatLocApp.jar:na]
    at com.nationallocums.Application.main(Application.java:13) [NatLocApp.jar:na]
Caused by: org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getEmbeddedServletContainerFactory(EmbeddedWebApplicationContext.java:183) ~[NatLocApp.jar:na]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:156) ~[NatLocApp.jar:na]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:130) ~[NatLocApp.jar:na]
    ... 8 common frames omitted

From my research I can see this has something to do with Tomcat not being embedded or maybe multiple instanced of Tomcat being included in the final JAR file, but I don't seem to be able to resolve the issue.

Here's what my pom.xml file looks like;

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-taglibs</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>

        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>

        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.4</version>
        </dependency>

        <dependency>
            <groupId>net.sf.opencsv</groupId>
            <artifactId>opencsv</artifactId>
            <version>2.3</version>
        </dependency>

        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.9.2</version>
        </dependency>
    </dependencies>

I've tried setting the tomcat dependency as having a scope of 'provided' and removing the scope tag completely, but neither seems to make any difference.

Answer 1

You should have the spring-boot-maven-plugin in your pom.xml file. And packaging set to jar.

Then you can:

$ mvn package
$ java -jar target/mymodule-0.0.1-SNAPSHOT.jar

Answer 2

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>

Solution Delete this line：“ <scope>provided</scope> ”

The possible values for the scope property are outlined here . The provided scope is described as the following:

This is much like compile, but indicates you expect the JDK or a container to provide the dependency at runtime . For example, when building a web application for the Java Enterprise Edition, you would set the dependency on the Servlet API and related Java EE APIs to scope provided because the web container provides those classes. This scope is only available on the compilation and test classpath, and is not transitive.