Incompatible types. Found: 'java.lang.String', required: 'byte, char, short or int' code example

Example: Incompatible types. Found: 'java.lang.String', required: 'byte, char, short or int'

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>