Spring Boot plus react deployment as .war

Question

I'm having trouble generating a .war file that I can deploy to tomcat with using Spring Boot and React.

My project stucture is as follows:

project_root
+--- backend/
   +--- src/
      +--- ...
   +--- pom.xml
+--- frontend/
   +--- public/
      +--- ...
   +--- src/
      +--- ...
   +--- package.json
   +--- pom.xml
+--- pom.xml

The frontend is created with "create-react-app" right now, but that can be changed if that helps to fix the problem.

If I package it as .jar and run it, everything works fine. If I package it as .war and deploy it on a tomcat 9 server I get 404 errors since the static resources cant be found and I cant figure out the problem with my configuration.

My root pom looks as follows:

<?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>plimplom</groupId>
    <artifactId>project</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>frontend</module>
        <module>backend</module>
    </modules>

</project>

My frontend pom looks as follows:

<?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>project</artifactId>
        <groupId>plimplom</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>frontend</artifactId>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
            <groupId>com.github.eirslett</groupId>
            <artifactId>frontend-maven-plugin</artifactId>
            <version>1.9.1</version>
            <configuration>
                <installDirectory>target</installDirectory>
            </configuration>
            <executions>
                <execution>
                    <id>install node and npm</id>
                    <goals>
                        <goal>install-node-and-npm</goal>
                    </goals>
                    <configuration>
                        <nodeVersion>v12.16.1</nodeVersion>
                        <npmVersion>6.13.4</npmVersion>
                    </configuration>
                </execution>
                <execution>
                    <id>npm install</id>
                    <goals>
                        <goal>npm</goal>
                    </goals>
                    <configuration>
                        <arguments>install</arguments>
                    </configuration>
                </execution>
                <execution>
                    <id>npm run build</id>
                    <goals>
                        <goal>npm</goal>
                    </goals>
                    <configuration>
                        <arguments>run build</arguments>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        </plugins>
    </build>
</project>

The backend pom looks as follows:

<?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>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>backend</artifactId>

    <packaging>war</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.build.targetEncoding>UTF-8</project.build.targetEncoding>
        <java.version>13</java.version>
        <maven.compiler.source>13</maven.compiler.source>
        <maven.compiler.target>13</maven.compiler.target>
    </properties>

    <dependencies>
        <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-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.2.4.RELEASE</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-antrun-plugin</artifactId>
                <version>1.8</version>
                <executions>
                    <execution>
                        <phase>generate-resources</phase>
                        <configuration>
                            <target>
                                <copy todir="${project.build.directory}/classes/public">
                                    <fileset dir="${project.basedir}/../frontend/build"/>
                                </copy>
                            </target>
                        </configuration>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

My Spring class looks as follows:

@SpringBootApplication
public class Application extends SpringBootServletInitializer {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(Application.class);
    }
}

I can't figure out what is wrong with this configuration and googleing the issue didn't help much. If there is any other information needed to fix this problem I'll add them.

Answer 1

did you tried

<plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-war-plugin</artifactId>
                    <version>${maven-war-plugin.version}</version>
</plugin>

Please let me know if you need the configuration example for that