Required maven dependencies for Apache POI to work

No, you don’t have to include all of POI‘s dependencies. Maven’s transitive dependency mechanism will take care of that. As noted you just have to express a dependency on the appropriate POI artifact. For example:

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.8-beta4</version>
</dependency>

Edit(UPDATE): I don’t know about previous versions but to resolve imports to XSSFWorkbook and other classes in org.apache.poi package you need to add dependency for poi-ooxml too. The dependencies will be:

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>