I am using JXLS Java library to generate excel reports. I am trying to run the sample getting started tutorial (Object collection output demo). As suggested in the tutorial http://jxls.sourceforge.net/getting_started.html I am using maven to specify the required libraries in my project build configuration file. Below is the java code used:
List<Employee> employees = generateSampleEmployeeData();    try(InputStream is = ObjectCollectionDemo.class.getResourceAsStream("object_collection_template1.xls")) {        try(OutputStream os = new FileOutputStream("target/" + fileName)) {            Context context = new Context();            context.putVar("employees", employees);            JxlsHelper.getInstance().processTemplate(is, os, context);

When i run the program in my eclipse i get the below exception:
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/poi/openxml4j/exceptions/InvalidFormatException    at java.lang.Class.getDeclaredMethods0(Native Method)    at java.lang.Class.privateGetDeclaredMethods(Unknown Source)    at java.lang.Class.privateGetMethodRecursive(Unknown Source)    at java.lang.Class.getMethod0(Unknown Source)    at java.lang.Class.getMethod(Unknown Source)    at org.jxls.util.TransformerFactory.createTransformer(TransformerFactory.java:34)    at org.jxls.util.JxlsHelper.createTransformer(JxlsHelper.java:217)    at org.jxls.util.JxlsHelper.processTemplate(JxlsHelper.java:104)    at com.ucas.ObjectCollectionDemo.main(ObjectCollectionDemo.java:42) Caused by: java.lang.ClassNotFoundException: org.apache.poi.openxml4j.exceptions.InvalidFormatException    at java.net.URLClassLoader.findClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)    at java.lang.ClassLoader.loadClass(Unknown Source)    ... 9 more

When i run it in debug mode i see the above exception occurs when it executes the below line:
Method initMethod = transformer.getMethod(INIT_METHOD, InputStream.class, OutputStream.class);

Java Version: 1.8

Environment: Windows 7

IDE : Eclipse Neon

JXLS Version: 2.4.0