The import org.apache.poi.xssf can not be resolved

Look for "poi-3.17.jar"!!!

1. Download from "https://poi.apache.org/download.html".
2. Click the one Binary Distribution -> poi-bin-3.17-20170915.tar.gz
3. Unzip the file download and look for this "poi-3.17.jar".

Problem solved and errors disappeared.

Hope this could help.

When using maven, for Apache POI, make sure to add all the latest dependencies related to Apache POI as follows:

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.0</version>
<dependency>
   <dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.0</version>
</dependency>

<dependency>
    <groupId>org.apache.xmlbeans</groupId>
    <artifactId>xmlbeans</artifactId>
    <version>3.1.0</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-scratchpad</artifactId>
    <version>4.1.0</version>
</dependency>

Save and run. Errors should be resolved.

for Poi/XSSF you need also dependency to poi-ooxml, like so

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.9</version>
</dependency>