Cell Background Color Change (eugenp#11400)

SeshuTechie · Seshu Thanneeru · web-flow · commit f84ba037512f · 2021-11-04T21:16:37.000+01:00
Co-authored-by: Seshu Thanneeru &lt;seshukumar.thanneeru@thoughtdata.com&gt;
diff --git a/apache-poi/src/main/java/com/baeldung/poi/excel/cellstyle/CellStyleHandler.java b/apache-poi/src/main/java/com/baeldung/poi/excel/cellstyle/CellStyleHandler.java
@@ -0,0 +1,30 @@
+package com.baeldung.poi.excel.cellstyle;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.FillPatternType;
+import org.apache.poi.ss.usermodel.IndexedColors;
+
+public class CellStyleHandler {
+
+    public void changeCellBackgroundColor(Cell cell) {
+        CellStyle cellStyle = cell.getCellStyle();
+        if(cellStyle == null) {
+            cellStyle = cell.getSheet().getWorkbook().createCellStyle();
+        }
+        cellStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex());
+        cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
+        cell.setCellStyle(cellStyle);
+    }
+
+    public void changeCellBackgroundColorWithPattern(Cell cell) {
+        CellStyle cellStyle = cell.getCellStyle();
+        if(cellStyle == null) {
+            cellStyle = cell.getSheet().getWorkbook().createCellStyle();
+        }
+        cellStyle.setFillBackgroundColor(IndexedColors.BLACK.index);
+        cellStyle.setFillPattern(FillPatternType.BIG_SPOTS);
+        cellStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex());
+        cell.setCellStyle(cellStyle);
+    }
+}
diff --git a/apache-poi/src/main/resources/cellstyle/CellStyleHandlerTest.xlsx b/apache-poi/src/main/resources/cellstyle/CellStyleHandlerTest.xlsx
diff --git a/apache-poi/src/test/java/com/baeldung/poi/excel/cellstyle/CellStyleHandlerUnitTest.java b/apache-poi/src/test/java/com/baeldung/poi/excel/cellstyle/CellStyleHandlerUnitTest.java
@@ -0,0 +1,56 @@
+package com.baeldung.poi.excel.cellstyle;
+
+import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+
+import static org.junit.Assert.assertEquals;
+
+public class CellStyleHandlerUnitTest {
+    private static final String FILE_NAME = "cellstyle/CellStyleHandlerTest.xlsx";
+    private static final int SHEET_INDEX = 0;
+    private static final int ROW_INDEX = 0;
+    private static final int CELL_INDEX = 0;
+
+    private String fileLocation;
+    private CellStyleHandler cellStyleHandler;
+
+    @Before
+    public void setup() throws URISyntaxException {
+        fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+        cellStyleHandler = new CellStyleHandler();
+    }
+
+    @Test
+    public void givenWorkbookCell_whenChangeCellBackgroundColor() throws IOException {
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(SHEET_INDEX);
+        Row row = sheet.getRow(ROW_INDEX);
+        Cell cell = row.getCell(CELL_INDEX);
+
+        cellStyleHandler.changeCellBackgroundColor(cell);
+
+        assertEquals(IndexedColors.LIGHT_BLUE.index, cell.getCellStyle().getFillForegroundColor());
+        workbook.close();
+    }
+
+    @Test
+    public void givenWorkbookCell_whenChangeCellBackgroundColorWithPattern() throws IOException {
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(SHEET_INDEX);
+        Row row = sheet.getRow(ROW_INDEX);
+        Cell cell = row.getCell(CELL_INDEX + 1);
+
+        cellStyleHandler.changeCellBackgroundColorWithPattern(cell);
+
+        assertEquals(IndexedColors.LIGHT_BLUE.index, cell.getCellStyle().getFillForegroundColor());
+        workbook.close();
+    }
+}
