helper classes for excel processing, tests (#1093)

* helper classes for excel processing, tests

* fix imports

* list declaration

apache-poi/src/test/java/com/baeldung/poi/excel/ExcelTest.java

@@ -0,0 +1,59 @@
+package com.baeldung.poi.excel;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import jxl.read.biff.BiffException;
+import java.util.Map;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.baeldung.poi.excel.ExcelPOIHelper;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import org.junit.Before;
+
+public class ExcelTest {
+
+    private ExcelPOIHelper excelPOIHelper;
+    private static String FILE_NAME = "temp.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void generateExcelFile() throws IOException {
+
+        File currDir = new File(".");
+        String path = currDir.getAbsolutePath();
+        fileLocation = path.substring(0, path.length() - 1) + FILE_NAME;
+
+        excelPOIHelper = new ExcelPOIHelper();
+        excelPOIHelper.writeExcel();
+
+    }
+
+    @Test
+    public void whenParsingPOIExcelFile_thenCorrect() throws IOException {
+        Map<Integer, List<String>> data = excelPOIHelper.readExcel(fileLocation);
+
+        assertEquals("Name", data.get(0)
+            .get(0));
+        assertEquals("Age", data.get(0)
+            .get(1));
+
+        assertEquals("John Smith", data.get(1)
+            .get(0));
+        assertEquals("20", data.get(1)
+            .get(1));
+
+        assertEquals("Ana Johnson", data.get(2)
+            .get(0));
+        assertEquals("30", data.get(2)
+            .get(1));
+
+    }
+
+}