[FIXED] Spring 5.1 + Tomcat 9 + Java 10 + moduled project = java.lang.NoClassDefFoundError: org/springframework/core/io/Resource

Issue

I'm completely stuck with the error:

SEVERE [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: 
 org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
Caused by: java.lang.NoClassDefFoundError:     org/springframework/core/io/Resource

I'm trying to create a project that is divided in several modules (like core, auth and so on), using Java 10, Spring 5.1 and Tomcat 9.

All webapp configurations are stored in the app module. Here is web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
     version="4.0">
<display-name>Prolly REST API</display-name>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/restapi-servlet.xml</param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
    <servlet-name>restapi</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>restapi</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>

And here is restapi-servlet.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xmlns:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans.xsd
   http://www.springframework.org/schema/mvc
   http://www.springframework.org/schema/mvc/spring-mvc.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context.xsd">

<context:component-scan base-package="com.roilen.code.prolly.core.rest"/>
<mvc:annotation-driven/>

Here is main pom.xml (parent and project based):

<?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>

<groupId>com.roilen.code.prolly</groupId>
<artifactId>ProllyServer</artifactId>
<version>1.0-SNAPSHOT</version>
<modules>
    <module>core</module>
    <module>app</module>
</modules>
<packaging>pom</packaging>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <packaging.type>jar</packaging.type>
    <java.version>10</java.version>
    <maven.compiler.source>${java.version}</maven.compiler.source>
    <maven.compiler.target>${java.version}</maven.compiler.target>
    <org.springframework.version>5.1.0.RELEASE</org.springframework.version>
</properties>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.1.0</version>
        </plugin>
    </plugins>
</build>

<dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.7</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <version>${org.springframework.version}</version>
    </dependency>
</dependencies>

And here is an app-module pom.xml:

<?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">
<parent>
    <artifactId>ProllyServer</artifactId>
    <groupId>com.roilen.code.prolly</groupId>
    <version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>

<artifactId>app</artifactId>
<packaging>war</packaging>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>3.2.2</version>
        </plugin>
        <plugin>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-maven-plugin</artifactId>
            <version>9.4.0.RC2</version>
            <configuration>
                <scanIntervalSeconds>3</scanIntervalSeconds>
                <webAppConfig>
                    <contextPath>/prolly</contextPath>
                    <extraClasspath>
                        target/classes;../core/target/classes;.asses;
                    </extraClasspath>
                </webAppConfig>
                <scanTargets>
                    <scanTarget>src/main/webapp</scanTarget>
                    <scanTarget>target/classes</scanTarget>
                    <scanTarget>../core/target/classes</scanTarget>
                </scanTargets>
            </configuration>
        </plugin>
    </plugins>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
            <includes>
                <include>**</include>
            </includes>
        </resource>
    </resources>
</build>

<dependencies>
    <dependency>
        <groupId>com.roilen.code.prolly</groupId>
        <artifactId>core</artifactId>
        <version>${project.version}</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>

</dependencies>

So, when I try to deploy the project to local tomcat server via Intellij IDEA i get the error above. The sources for the project can be found here: https://drive.google.com/open?id=1ThH9BCLpEYvrTwglkqrRhjIpv4nJ_YcW

Thanks!

Solution

Ok, so the problem was as simple as usual. The error was that there were two wars in the project settings and the one that was being deployed to the server was a wrong one (the project core war, not the app module)

So, I've changed the war in the configuration settings, et voila!

Hope this could save several hours to those who created moduled apps :)

Answered By - Alexandra Lutikova