<plugin>
    <artifactId>maven-resources-plugin</artifactId>
    <version>2.6</version>
    <executions>
        <execution>
            <id>copy-resources</id>
            <phase>validate</phase>
            <goals>
                <goal>copy-resources</goal>
            </goals>
            <configuration>
                <outputDirectory>${basedir}/target/classes/static</outputDirectory>
                <resources>
                    <resource>
                        <directory>src/main/webapp</directory>
                        <filtering>true</filtering>
                    </resource>
                </resources>
            </configuration>
        </execution>
    </executions>
</plugin>