Chagne term 'contents' -> 'body', Write simple test code

.gitignore

@@ -1,2 +1,3 @@
 .idea/
 .gradle/
+out/

README.md

@@ -36,7 +36,7 @@ dependencies {
 // Rendered Field Order is same as Dto field order
 public class ExcelDto {
 
-  // Annotation Case 1. no headerStyle and contentsStyle
+  // Annotation Case 1. no headerStyle and bodyStyle
   @ExcelColumn(headerName = "User Name")
   private String name;
   
@@ -46,24 +46,24 @@ public class ExcelDto {
   )
   private int age;
   
-  // Annotation Case 3. You can also configure contents style
+  // Annotation Case 3. You can also configure bodyStyle style
   @ExcelColumn(headerName = "Happy BirthDay",
-      contentsStyle = @ExcelColumnStyle(excelCellStyleClass = DefaultExcelCellStyle.class, enumName = "CONTENTS")
+      bodyStyle = @ExcelColumnStyle(excelCellStyleClass = DefaultExcelCellStyle.class, enumName = "BODY")
   )
   private LocalDate birthDay;
 
 }
 ```
 
-If you want to config default style in class, you should use @DefaultHeaderStyle or @DefaultContentsStyle.
+If you want to config default style in class, you should use @DefaultHeaderStyle or @DefaultBodyStyle.
 This style will be applied to all fields having not field style in this class.
 
 ```java
 @DefaultHeaderStyle(
     style = @ExcelColumnStyle(excelCellStyleClass = DefaultExcelCellStyle.class, enumName = "BLUE_HEADER")
 )
-@DefaultContentsStyle(
+@DefaultBodyStyle(
-	style = @ExcelColumnStyle(excelCellStyleClass = DefaultExcelCellStyle.class, enumName = "CONTENTS")
+	style = @ExcelColumnStyle(excelCellStyleClass = DefaultExcelCellStyle.class, enumName = "BODY")
 )
 public class ExcelDto {
 	
@@ -192,7 +192,7 @@ public enum CustomCellStyle implements ExcelCellStyle {
 public class ExcelDto {
 
   @ExcelColumn(headerName = "Field Header Title",
-      contentsStyle = @ExcelColumnStyle(excelCellStyleClass = CustomCellStyle.class, enumName = "CUSTOM_HEADER")
+      bodyStyle = @ExcelColumnStyle(excelCellStyleClass = CustomCellStyle.class, enumName = "CUSTOM_HEADER")
   )
   private String field1;
 

build.gradle

@@ -14,4 +14,8 @@ repositories {
 dependencies {
     compile 'org.apache.poi:poi:4.1.2'
     compile 'org.apache.poi:poi-ooxml:4.1.2'
+
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.3.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.3.1'
+    testCompile group: 'org.assertj', name: 'assertj-core', version: '3.6.1'
 }

src/main/java/com/lannstark/DefaultBodyStyle.java

@@ -7,7 +7,7 @@ import java.lang.annotation.Target;
 
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
-public @interface DefaultContentsStyle {
+public @interface DefaultBodyStyle {
 
 	ExcelColumnStyle style();
 

src/main/java/com/lannstark/ExcelColumn.java

@@ -14,6 +14,6 @@ public @interface ExcelColumn {
 	String headerName() default "";
 
 	ExcelColumnStyle headerStyle() default @ExcelColumnStyle(excelCellStyleClass = NoExcelCellStyle.class);
-	ExcelColumnStyle contentsStyle() default @ExcelColumnStyle(excelCellStyleClass = NoExcelCellStyle.class);
+	ExcelColumnStyle bodyStyle() default @ExcelColumnStyle(excelCellStyleClass = NoExcelCellStyle.class);
 
 }

src/main/java/com/lannstark/excel/ExcelFile.java

@@ -2,9 +2,12 @@ package com.lannstark.excel;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.List;
 
-public interface ExcelFile {
+public interface ExcelFile<T> {
 
 	void write(OutputStream stream) throws IOException;
 
+	void addRows(List<T> data);
+
 }

src/main/java/com/lannstark/excel/SXSSFExcelFile.java

@@ -15,11 +15,12 @@ import org.apache.poi.xssf.streaming.SXSSFWorkbook;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.reflect.Field;
+import java.util.Collections;
 import java.util.List;
 
 import static com.lannstark.utils.SuperClassReflectionUtils.getField;
 
-public abstract class SXSSFExcelFile<T> implements ExcelFile {
+public abstract class SXSSFExcelFile<T> implements ExcelFile<T> {
 
 	protected static final SpreadsheetVersion supplyExcelVersion = SpreadsheetVersion.EXCEL2007;
 
@@ -28,28 +29,37 @@ public abstract class SXSSFExcelFile<T> implements ExcelFile {
 	protected ExcelRenderResource resource;
 
 	/**
-	 * OneSheetExcelFile
+	 *SXSSFExcelFile
+	 * @param type Class type to be rendered
+	 */
+	public SXSSFExcelFile(Class<T> type) {
+		this(Collections.emptyList(), type, new DefaultDataFormatDecider());
+	}
+
+	/**
+	 * SXSSFExcelFile
 	 * @param data List Data to render excel file. data should have at least one @ExcelColumn on fields
 	 * @param type Class type to be rendered
 	 */
 	public SXSSFExcelFile(List<T> data, Class<T> type) {
-		this.wb = new SXSSFWorkbook();
+		this(data, type, new DefaultDataFormatDecider());
-		this.resource = ExcelRenderResourceFactory.prepareRenderResource(type, wb, new DefaultDataFormatDecider());
-		renderExcel(data);
 	}
 
 	/**
-	 * OneSheetExcelFile
+	 * SXSSFExcelFile
 	 * @param data List Data to render excel file. data should have at least one @ExcelColumn on fields
 	 * @param type Class type to be rendered
 	 * @param dataFormatDecider Custom DataFormatDecider
 	 */
 	public SXSSFExcelFile(List<T> data, Class<T> type, DataFormatDecider dataFormatDecider) {
+		validateData(data);
 		this.wb = new SXSSFWorkbook();
 		this.resource = ExcelRenderResourceFactory.prepareRenderResource(type, wb, dataFormatDecider);
 		renderExcel(data);
 	}
 
+	protected void validateData(List<T> data) { }
+
 	protected abstract void renderExcel(List<T> data);
 
 	protected void renderHeadersWithNewSheet(Sheet sheet, int rowIndex, int columnStartIndex) {
@@ -62,7 +72,7 @@ public abstract class SXSSFExcelFile<T> implements ExcelFile {
 		}
 	}
 
-	protected void renderContent(Object data, int rowIndex, int columnStartIndex) {
+	protected void renderBody(Object data, int rowIndex, int columnStartIndex) {
 		Row row = sheet.createRow(rowIndex);
 		int columnIndex = columnStartIndex;
 		for (String dataFieldName : resource.getDataFieldNames()) {
@@ -70,7 +80,7 @@ public abstract class SXSSFExcelFile<T> implements ExcelFile {
 			try {
 				Field field = getField(data.getClass(), (dataFieldName));
 				field.setAccessible(true);
-				cell.setCellStyle(resource.getCellStyle(dataFieldName, ExcelRenderLocation.CONTENTS));
+				cell.setCellStyle(resource.getCellStyle(dataFieldName, ExcelRenderLocation.BODY));
 				Object cellValue = field.get(data);
 				renderCellValue(cell, cellValue);
 			} catch (Exception e) {

src/main/java/com/lannstark/excel/multiplesheet/MultiSheetExcelFile.java

@@ -12,13 +12,19 @@ import java.util.List;
  * - support Excel Version over 2007
  * - support multi sheet rendering
  * - support Dffierent DataFormat by Class Type
- * - support Custom CellStyle according to (header or contents) and data field
+ * - support Custom CellStyle according to (header or body) and data field
  */
 public class MultiSheetExcelFile<T> extends SXSSFExcelFile<T> {
 
 	private static final int maxRowCanBeRendered = supplyExcelVersion.getMaxRows() - 1;
 	private static final int ROW_START_INDEX = 0;
 	private static final int COLUMN_START_INDEX = 0;
+	private int currentRowIndex = ROW_START_INDEX;
+
+	public MultiSheetExcelFile(Class<T> type) {
+		super(type);
+		wb.setZip64Mode(Zip64Mode.Always);
+	}
 
 	/*
 	 * If you use SXSSF with hug data, you need to set zip mode
@@ -42,16 +48,17 @@ public class MultiSheetExcelFile<T> extends SXSSFExcelFile<T> {
 			return ;
 		}
 
+		// 2. Render body
 		createNewSheetWithHeader();
-		int renderedDataCnt = 0;
+		addRows(data);
-		int rowIndex = ROW_START_INDEX + 1;
+	}
-		for (Object renderedData : data) {
-			renderContent(renderedData, rowIndex++, COLUMN_START_INDEX);
-			renderedDataCnt ++;
 
-			if (renderedDataCnt == maxRowCanBeRendered) {
+	@Override
-				renderedDataCnt = 0;
+	public void addRows(List<T> data) {
-				rowIndex = 1;
+		for (Object renderedData : data) {
+			renderBody(renderedData, currentRowIndex++, COLUMN_START_INDEX);
+			if (currentRowIndex == maxRowCanBeRendered) {
+				currentRowIndex = 1;
 				createNewSheetWithHeader();
 			}
 		}
@@ -60,6 +67,7 @@ public class MultiSheetExcelFile<T> extends SXSSFExcelFile<T> {
 	private void createNewSheetWithHeader() {
 		sheet = wb.createSheet();
 		renderHeadersWithNewSheet(sheet, ROW_START_INDEX, COLUMN_START_INDEX);
+		currentRowIndex++;
 	}
 
 }

src/main/java/com/lannstark/excel/onesheet/OneSheetExcelFile.java

@@ -10,25 +10,29 @@ import java.util.List;
  *
  * - support Excel Version over 2007
  * - support one sheet rendering
- * - support Dffierent DataFormat by Class Type
+ * - support different DataFormat by Class Type
- * - support Custom CellStyle according to (header or contents) and data field
+ * - support Custom CellStyle according to (header or body) and data field
  */
 public final class OneSheetExcelFile<T> extends SXSSFExcelFile<T> {
 
 	private static final int ROW_START_INDEX = 0;
 	private static final int COLUMN_START_INDEX = 0;
+	private int currentRowIndex = ROW_START_INDEX;
+
+	public OneSheetExcelFile(Class<T> type) {
+		super(type);
+	}
 
 	public OneSheetExcelFile(List<T> data, Class<T> type) {
 		super(data, type);
-		validateMaxRow(data);
 	}
 
 	public OneSheetExcelFile(List<T> data, Class<T> type, DataFormatDecider dataFormatDecider) {
 		super(data, type, dataFormatDecider);
-		validateMaxRow(data);
 	}
 
-	private void validateMaxRow(List<?> data) {
+	@Override
+	protected void validateData(List<T> data) {
 		int maxRows = supplyExcelVersion.getMaxRows();
 		if (data.size() > maxRows) {
 			throw new IllegalArgumentException(
@@ -40,17 +44,21 @@ public final class OneSheetExcelFile<T> extends SXSSFExcelFile<T> {
 	public void renderExcel(List<T> data) {
 		// 1. Create sheet and renderHeader
 		sheet = wb.createSheet();
-		renderHeadersWithNewSheet(sheet, ROW_START_INDEX, COLUMN_START_INDEX);
+		renderHeadersWithNewSheet(sheet, currentRowIndex++, COLUMN_START_INDEX);
 
 		if (data.isEmpty()) {
 			return;
 		}
 
-		// 2. Render Contents
+		// 2. Render Body
-		int rowIndex = ROW_START_INDEX + 1;
 		for (Object renderedData : data) {
-			renderContent(renderedData, rowIndex++, COLUMN_START_INDEX);
+			renderBody(renderedData, currentRowIndex++, COLUMN_START_INDEX);
 		}
 	}
 
+	@Override
+	public void addRows(List<T> data) {
+		renderBody(data, currentRowIndex++, COLUMN_START_INDEX);
+	}
+
 }

src/main/java/com/lannstark/resource/DefaultDataFormatDecider.java

@@ -8,26 +8,37 @@ import java.util.List;
 public class DefaultDataFormatDecider implements DataFormatDecider {
 
 	private static final String CURRENT_FORMAT = "#,##0";
+	private static final String FLOAT_FORMAT_2_DECIMAL_PLACES = "#,##0.00";
 	private static final String DEFAULT_FORMAT = "";
 
 	@Override
 	public short getDataFormat(DataFormat dataFormat, Class<?> type) {
-		if (isNumericType(type)) {
+		if (isFloatType(type)) {
+			return dataFormat.getFormat(FLOAT_FORMAT_2_DECIMAL_PLACES);
+		}
+
+		if (isIntegerType(type)) {
 			return dataFormat.getFormat(CURRENT_FORMAT);
 		}
 		return dataFormat.getFormat(DEFAULT_FORMAT);
 	}
 
-	private boolean isNumericType(Class<?> type) {
+	private boolean isFloatType(Class<?> type) {
-		List<Class<?>> numericTypes = Arrays.asList(
+		List<Class<?>> floatTypes = Arrays.asList(
-				Byte.class, byte.class,
-				Short.class, short.class,
-				Integer.class, int.class,
-				Long.class, long.class,
 				Float.class, float.class,
 				Double.class, double.class
 		);
-		return numericTypes.contains(type);
+		return floatTypes.contains(type);
+	}
+
+	private boolean isIntegerType(Class<?> type) {
+		List<Class<?>> integerTypes = Arrays.asList(
+				Byte.class, byte.class,
+				Short.class, short.class,
+				Integer.class, int.class,
+				Long.class, long.class
+		);
+		return integerTypes.contains(type);
 	}
 
 }

src/main/java/com/lannstark/resource/ExcelRenderLocation.java

@@ -2,6 +2,6 @@ package com.lannstark.resource;
 
 public enum ExcelRenderLocation {
 
-	HEADER, CONTENTS
+	HEADER, BODY
 
 }

src/main/java/com/lannstark/resource/ExcelRenderResource.java

@@ -29,14 +29,6 @@ public class ExcelRenderResource {
 		return excelHeaderNames.get(dataFieldName);
 	}
 
-	public PreCalculatedCellStyleMap getStyleMap() {
-		return styleMap;
-	}
-
-	public Map<String, String> getExcelHeaderNames() {
-		return excelHeaderNames;
-	}
-
 	public List<String> getDataFieldNames() {
 		return dataFieldNames;
 	}

src/main/java/com/lannstark/resource/ExcelRenderResourceFactory.java

@@ -1,6 +1,6 @@
 package com.lannstark.resource;
 
-import com.lannstark.DefaultContentsStyle;
+import com.lannstark.DefaultBodyStyle;
 import com.lannstark.DefaultHeaderStyle;
 import com.lannstark.ExcelColumn;
 import com.lannstark.ExcelColumnStyle;
@@ -34,7 +34,7 @@ public final class ExcelRenderResourceFactory {
 		List<String> fieldNames = new ArrayList<>();
 
 		ExcelColumnStyle classDefinedHeaderStyle = getHeaderExcelColumnStyle(type);
-		ExcelColumnStyle classDefinedContentsStyle = getContentsExcelColumnStyle(type);
+		ExcelColumnStyle classDefinedBodyStyle = getBodyExcelColumnStyle(type);
 
 		for (Field field : getAllFields(type)) {
 			if (field.isAnnotationPresent(ExcelColumn.class)) {
@@ -46,8 +46,8 @@ public final class ExcelRenderResourceFactory {
 				Class<?> fieldType = field.getType();
 				styleMap.put(
 						fieldType,
-						ExcelCellKey.of(field.getName(), ExcelRenderLocation.CONTENTS),
+						ExcelCellKey.of(field.getName(), ExcelRenderLocation.BODY),
-						getCellStyle(decideAppliedStyleAnnotation(classDefinedContentsStyle, annotation.contentsStyle())), wb);
+						getCellStyle(decideAppliedStyleAnnotation(classDefinedBodyStyle, annotation.bodyStyle())), wb);
 				fieldNames.add(field.getName());
 				headerNamesMap.put(field.getName(), annotation.headerName());
 			}
@@ -67,12 +67,12 @@ public final class ExcelRenderResourceFactory {
 		return ((DefaultHeaderStyle) annotation).style();
 	}
 
-	private static ExcelColumnStyle getContentsExcelColumnStyle(Class<?> clazz) {
+	private static ExcelColumnStyle getBodyExcelColumnStyle(Class<?> clazz) {
-		Annotation annotation = getAnnotation(clazz, DefaultContentsStyle.class);
+		Annotation annotation = getAnnotation(clazz, DefaultBodyStyle.class);
 		if (annotation == null) {
 			return null;
 		}
-		return ((DefaultContentsStyle) annotation).style();
+		return ((DefaultBodyStyle) annotation).style();
 	}
 
 	private static ExcelColumnStyle decideAppliedStyleAnnotation(ExcelColumnStyle classAnnotation,
@@ -100,7 +100,7 @@ public final class ExcelRenderResourceFactory {
 	}
 
 	@SuppressWarnings("unchecked")
-	private static ExcelCellStyle findExcelCellStyle(Class excelCellStyles, String enumName) {
+	private static ExcelCellStyle findExcelCellStyle(Class<?> excelCellStyles, String enumName) {
 		try {
 			return (ExcelCellStyle) Enum.valueOf((Class<Enum>) excelCellStyles, enumName);
 		} catch (NullPointerException e) {

src/main/java/com/lannstark/resource/collection/PreCalculatedCellStyleMap.java

@@ -14,15 +14,15 @@ import java.util.Map;
  * PreCalculatedCellStyleMap
  *
  * Determines cell's style
- * In currently, PreCalculatedCellSylteMap determines {org.apache.poi.ss.usermodel.DataFormat}
+ * In currently, PreCalculatedCellStyleMap determines {org.apache.poi.ss.usermodel.DataFormat}
  *
  */
 public class PreCalculatedCellStyleMap {
 
-	private final DataFormatDecider store;
+	private final DataFormatDecider dataFormatDecider;
 
-	public PreCalculatedCellStyleMap(DataFormatDecider store) {
+	public PreCalculatedCellStyleMap(DataFormatDecider dataFormatDecider) {
-		this.store = store;
+		this.dataFormatDecider = dataFormatDecider;
 	}
 
 	private final Map<ExcelCellKey, CellStyle> cellStyleMap = new HashMap<>();
@@ -30,7 +30,7 @@ public class PreCalculatedCellStyleMap {
 	public void put(Class<?> fieldType, ExcelCellKey excelCellKey, ExcelCellStyle excelCellStyle, Workbook wb) {
 		CellStyle cellStyle = wb.createCellStyle();
 		DataFormat dataFormat = wb.createDataFormat();
-		cellStyle.setDataFormat(store.getDataFormat(dataFormat, fieldType));
+		cellStyle.setDataFormat(dataFormatDecider.getDataFormat(dataFormat, fieldType));
 		excelCellStyle.apply(cellStyle);
 		cellStyleMap.put(excelCellKey, cellStyle);
 	}

src/main/java/com/lannstark/style/DefaultExcelCellStyle.java

@@ -17,7 +17,7 @@ public enum DefaultExcelCellStyle implements ExcelCellStyle {
 			DefaultExcelBorders.newInstance(ExcelBorderStyle.THIN), DefaultExcelAlign.CENTER_CENTER),
 	BLUE_HEADER(DefaultExcelColor.rgb(223, 235, 246),
 			DefaultExcelBorders.newInstance(ExcelBorderStyle.THIN), DefaultExcelAlign.CENTER_CENTER),
-	CONTENTS(DefaultExcelColor.rgb(255, 255, 255),
+	BODY(DefaultExcelColor.rgb(255, 255, 255),
 			DefaultExcelBorders.newInstance(ExcelBorderStyle.THIN), DefaultExcelAlign.RIGHT_CENTER);
 
 	private final ExcelColor backgroundColor;

src/main/java/com/lannstark/utils/SuperClassReflectionUtils.java

@@ -15,7 +15,7 @@ public final class SuperClassReflectionUtils {
 
 	public static List<Field> getAllFields(Class<?> clazz) {
 		List<Field> fields = new ArrayList<>();
-		for (Class clazzInClasses : getAllClassesIncludingSuperClasses(clazz, true)) {
+		for (Class<?> clazzInClasses : getAllClassesIncludingSuperClasses(clazz, true)) {
 			fields.addAll(Arrays.asList(clazzInClasses.getDeclaredFields()));
 		}
 		return fields;
@@ -23,7 +23,7 @@ public final class SuperClassReflectionUtils {
 
 	public static Annotation getAnnotation(Class<?> clazz,
 										   Class<? extends Annotation> targetAnnotation) {
-		for (Class clazzInClasses : getAllClassesIncludingSuperClasses(clazz, false)) {
+		for (Class<?> clazzInClasses : getAllClassesIncludingSuperClasses(clazz, false)) {
 			if (clazzInClasses.isAnnotationPresent(targetAnnotation)) {
 				return clazzInClasses.getAnnotation(targetAnnotation);
 			}
@@ -32,7 +32,7 @@ public final class SuperClassReflectionUtils {
 	}
 
 	public static Field getField(Class<?> clazz, String name) throws Exception {
-		for (Class clazzInClasses : getAllClassesIncludingSuperClasses(clazz, false)) {
+		for (Class<?> clazzInClasses : getAllClassesIncludingSuperClasses(clazz, false)) {
 			for (Field field : clazzInClasses.getDeclaredFields()) {
 				if (field.getName().equals(name)) {
 					return clazzInClasses.getDeclaredField(name);
@@ -42,8 +42,8 @@ public final class SuperClassReflectionUtils {
 		throw new NoSuchFieldException();
 	}
 
-	private static List<Class> getAllClassesIncludingSuperClasses(Class<?> clazz, boolean fromSuper) {
+	private static List<Class<?>> getAllClassesIncludingSuperClasses(Class<?> clazz, boolean fromSuper) {
-		List<Class> classes = new ArrayList<>();
+		List<Class<?>> classes = new ArrayList<>();
 		while (clazz != null) {
 			classes.add(clazz);
 			clazz = clazz.getSuperclass();

src/test/java/com/lannstark/dto/ExcelDto.java

@@ -0,0 +1,21 @@
+package com.lannstark.dto;
+
+import com.lannstark.DefaultHeaderStyle;
+import com.lannstark.ExcelColumn;
+import com.lannstark.ExcelColumnStyle;
+import com.lannstark.style.BlueHeaderStyle;
+import com.lannstark.style.BlackHeaderStyle;
+
+@DefaultHeaderStyle(style = @ExcelColumnStyle(excelCellStyleClass = BlueHeaderStyle.class))
+public class ExcelDto {
+
+    @ExcelColumn(headerName = "name")
+    private String name;
+
+    private String hideColumn;
+
+    @ExcelColumn(headerName = "age",
+            headerStyle = @ExcelColumnStyle(excelCellStyleClass = BlackHeaderStyle.class))
+    private int age;
+
+}

src/test/java/com/lannstark/resource/ExcelRenderResourceFactoryTest.java

@@ -0,0 +1,43 @@
+package com.lannstark.resource;
+
+import com.lannstark.dto.ExcelDto;
+import org.apache.poi.ss.usermodel.BorderStyle;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.usermodel.HorizontalAlignment;
+import org.apache.poi.ss.usermodel.VerticalAlignment;
+import org.apache.poi.xssf.streaming.SXSSFWorkbook;
+import org.apache.poi.xssf.usermodel.XSSFColor;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ExcelRenderResourceFactoryTest {
+
+    @Test
+    public void excelRenderResourceCreationTest() {
+        // given & when
+        ExcelRenderResource resource
+                = ExcelRenderResourceFactory.prepareRenderResource(ExcelDto.class, new SXSSFWorkbook(), new DefaultDataFormatDecider());
+
+        // then
+        assertThat(resource.getDataFieldNames()).isEqualTo(Arrays.asList("name", "age"));
+
+        assertCenterThinCellStyle(resource.getCellStyle("name", ExcelRenderLocation.HEADER), (byte) 223, (byte) 235, (byte) 246);
+        assertCenterThinCellStyle(resource.getCellStyle("age", ExcelRenderLocation.HEADER), (byte) 0, (byte) 0, (byte) 0);
+    }
+
+    private void assertCenterThinCellStyle(CellStyle cellStyle,
+                                 byte red, byte green, byte blue) {
+        assertThat(cellStyle.getAlignment()).isEqualTo(HorizontalAlignment.CENTER);
+        assertThat(cellStyle.getVerticalAlignment()).isEqualTo(VerticalAlignment.CENTER);
+        assertThat(cellStyle.getBorderTop()).isEqualTo(BorderStyle.THIN);
+        assertThat(cellStyle.getBorderRight()).isEqualTo(BorderStyle.THIN);
+        assertThat(cellStyle.getBorderLeft()).isEqualTo(BorderStyle.THIN);
+        assertThat(cellStyle.getBorderBottom()).isEqualTo(BorderStyle.THIN);
+        XSSFColor nameHeaderCellColor = (XSSFColor) cellStyle.getFillForegroundColorColor();
+        assertThat(nameHeaderCellColor.getRGB()).isEqualTo(new Byte[]{red, green, blue});
+    }
+
+}

src/test/java/com/lannstark/style/BlackHeaderStyle.java

@@ -0,0 +1,17 @@
+package com.lannstark.style;
+
+import com.lannstark.style.align.DefaultExcelAlign;
+import com.lannstark.style.border.DefaultExcelBorders;
+import com.lannstark.style.border.ExcelBorderStyle;
+import com.lannstark.style.configurer.ExcelCellStyleConfigurer;
+
+public class BlackHeaderStyle extends CustomExcelCellStyle {
+
+    @Override
+    public void configure(ExcelCellStyleConfigurer configurer) {
+        configurer.foregroundColor(0, 0, 0)
+                .excelBorders(DefaultExcelBorders.newInstance(ExcelBorderStyle.THIN))
+                .excelAlign(DefaultExcelAlign.CENTER_CENTER);
+    }
+
+}

src/test/java/com/lannstark/style/BlueHeaderStyle.java

@@ -0,0 +1,17 @@
+package com.lannstark.style;
+
+import com.lannstark.style.align.DefaultExcelAlign;
+import com.lannstark.style.border.DefaultExcelBorders;
+import com.lannstark.style.border.ExcelBorderStyle;
+import com.lannstark.style.configurer.ExcelCellStyleConfigurer;
+
+public class BlueHeaderStyle extends CustomExcelCellStyle {
+
+    @Override
+    public void configure(ExcelCellStyleConfigurer configurer) {
+        configurer.foregroundColor(223, 235, 246)
+                .excelBorders(DefaultExcelBorders.newInstance(ExcelBorderStyle.THIN))
+                .excelAlign(DefaultExcelAlign.CENTER_CENTER);
+    }
+
+}