vaadin-framework/compatibility-client/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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-root</artifactId>
        <version>8.15-SNAPSHOT</version>
    </parent>
    <artifactId>vaadin-compatibility-client</artifactId>
    <name>vaadin-compatibility-client</name>
    <packaging>jar</packaging>

    <url>https://vaadin.com/</url>
    <description>Vaadin 7 compatibility package for Vaadin 8</description>
    <properties>
        <!-- These files are directly from Vaadin 7 -->
        <sonar.skip>true</sonar.skip>
    </properties>
    <dependencies>
        <!-- Project modules -->
        <dependency>
            <groupId>com.vaadin</groupId>
            <artifactId>vaadin-client</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>${project.groupId}</groupId>
            <artifactId>vaadin-compatibility-server</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>${project.groupId}</groupId>
            <artifactId>vaadin-compatibility-shared</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <index>false</index>
                        <manifest>
                            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                        </manifest>
                        <manifestEntries>
                            <Vaadin-Package-Version>1</Vaadin-Package-Version>
                            <Vaadin-Widgetsets>com.vaadin.v7.Vaadin7WidgetSet</Vaadin-Widgetsets>
                        </manifestEntries>
                    </archive>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>checkstyle</goal>
                        </goals>
                        <phase>process-sources</phase>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <artifactId>maven-resources-plugin</artifactId>
                <executions>
                    <!-- Copy .java files to package -->
                    <execution>
                        <id>copy-sources</id>
                        <!-- here the phase you need -->
                        <phase>process-resources</phase>
                        <goals>
                            <goal>copy-resources</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${project.build.outputDirectory}</outputDirectory>
                            <resources>
                                <resource>
                                    <directory>src/main/resources</directory>
                                    <filtering>false</filtering>
                                </resource>
                                <resource>
                                    <directory>src/main/java</directory>
                                    <filtering>false</filtering>
                                </resource>
                            </resources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>