ExcelUtility Jira issue BAEL-5198 (#11503)

* CODE REFACTOR AND ADDED UNIT TEST

* SMALL CHANGE

* FIXED TESTS TIMEZONE ISSUES

Co-authored-by: Olsi Seferi <olsi.seferi@sisal.al>

apache-poi/src/main/java/com/baeldung/poi/excel/ExcelUtility.java

@@ -0,0 +1,66 @@
+package com.baeldung.poi.excel;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+public class ExcelUtility {
+	private static final String ENDLINE = System.getProperty("line.separator");
+
+	public static String readExcel(String filePath) throws IOException {
+		File file = new File(filePath);
+		FileInputStream inputStream = null;
+		StringBuilder toReturn = new StringBuilder();
+		try {
+			inputStream = new FileInputStream(file);
+			Workbook baeuldungWorkBook = new XSSFWorkbook(inputStream);
+			for (Sheet sheet : baeuldungWorkBook) {
+				toReturn.append("--------------------------------------------------------------------").append(ENDLINE);
+				toReturn.append("Worksheet :").append(sheet.getSheetName()).append(ENDLINE);
+				toReturn.append("--------------------------------------------------------------------").append(ENDLINE);
+				int firstRow = sheet.getFirstRowNum();
+				int lastRow = sheet.getLastRowNum();
+				for (int index = firstRow + 1; index <= lastRow; index++) {
+					Row row = sheet.getRow(index);
+					toReturn.append("|| ");
+					for (int cellIndex = row.getFirstCellNum(); cellIndex < row.getLastCellNum(); cellIndex++) {
+						Cell cell = row.getCell(cellIndex, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
+						printCellValue(cell, toReturn);
+					}
+					toReturn.append(" ||").append(ENDLINE);
+				}
+			}
+			inputStream.close();
+
+		} catch (IOException e) {
+			throw e;
+		}
+		return toReturn.toString();
+	}
+
+	public static void printCellValue(Cell cell, StringBuilder toReturn) {
+		CellType cellType = cell.getCellType().equals(CellType.FORMULA) ? cell.getCachedFormulaResultType()
+				: cell.getCellType();
+		if (cellType.equals(CellType.STRING)) {
+			toReturn.append(cell.getStringCellValue()).append(" | ");
+		}
+		if (cellType.equals(CellType.NUMERIC)) {
+			if (DateUtil.isCellDateFormatted(cell)) {
+				toReturn.append(cell.getDateCellValue()).append(" | ");
+			} else {
+				toReturn.append(cell.getNumericCellValue()).append(" | ");
+			}
+		}
+		if (cellType.equals(CellType.BOOLEAN)) {
+			toReturn.append(cell.getBooleanCellValue()).append(" | ");
+		}
+	}
+}

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

@@ -0,0 +1,54 @@
+package com.baeldung.poi.excel;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class ExcelUtilityUnitTest {
+	private static final String FILE_NAME = "baeldung.xlsx";
+	private String fileLocation;
+	private static final String ENDLINE = System.getProperty("line.separator");
+	private StringBuilder output;
+
+	@Before
+	public void setupUnitTest() throws IOException, URISyntaxException, ParseException {
+		output = new StringBuilder();
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("Worksheet :Sheet1").append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("|| Name1 | Surname1 | 3.55696564113E11 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021").toString()).append(" | ‡ |  ||")
+				.append(ENDLINE);
+		output.append("|| Name2 | Surname2 | 5.646513512E9 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/12/2021").toString()).append(" | false |  ||")
+				.append(ENDLINE);
+		output.append("|| Name3 | Surname3 | 3.55696564113E11 | ").append(new SimpleDateFormat("dd/MM/yyyy").parse("4/11/2021").toString()).append(" | 7.17039641738E11 |  ||")
+				.append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("Worksheet :Sheet2").append(ENDLINE);
+		output.append("--------------------------------------------------------------------").append(ENDLINE);
+		output.append("|| Name4 | Surname4 | 3.55675623232E11 | 13/04/2021 |  ||").append(ENDLINE);
+
+		fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+	}
+
+	@Test
+	public void givenStringPath_whenReadExcel_thenReturnStringValue() throws IOException {
+		assertEquals(output.toString(), ExcelUtility.readExcel(fileLocation));
+
+	}
+
+	@Test
+	public void givenStringPath_whenReadExcel_thenThrowException() {
+		assertThrows(IOException.class, () -> {
+			ExcelUtility.readExcel("baeldung");
+		});
+	}
+
+}