bug: fix error about range of HeadFontStyle(#326)

Author: wangmiscoding

fastexcel-core/src/main/java/cn/idev/excel/write/metadata/style/WriteCellStyle.java

@@ -162,7 +162,7 @@ public static void merge(WriteCellStyle source, WriteCellStyle target) {
         }
         if (source.getWriteFont() != null) {
             if (target.getWriteFont() == null) {
-                target.setWriteFont(source.getWriteFont());
+                target.setWriteFont(source.getWriteFont().clone());
             } else {
                 WriteFont.merge(source.getWriteFont(), target.getWriteFont());
             }

fastexcel-core/src/main/java/cn/idev/excel/write/metadata/style/WriteFont.java

@@ -115,4 +115,20 @@ public static void merge(WriteFont source, WriteFont target) {
             target.setBold(source.getBold());
         }
     }
+
+
+    @Override
+    public WriteFont clone() {
+        WriteFont writeFont = new WriteFont();
+        writeFont.setFontName(getFontName());
+        writeFont.setFontHeightInPoints(getFontHeightInPoints());
+        writeFont.setItalic(getItalic());
+        writeFont.setStrikeout(getStrikeout());
+        writeFont.setColor(getColor());
+        writeFont.setTypeOffset(getTypeOffset());
+        writeFont.setUnderline(getUnderline());
+        writeFont.setCharset(getCharset());
+        writeFont.setBold(getBold());
+        return writeFont;
+    }
 }

fastexcel-test/src/test/java/cn/idev/excel/test/demo/write/ColorDemoData.java

@@ -0,0 +1,31 @@
+package cn.idev.excel.test.demo.write;
+
+import cn.idev.excel.annotation.ExcelProperty;
+import cn.idev.excel.annotation.write.style.HeadFontStyle;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import lombok.Getter;
+import org.apache.poi.ss.usermodel.Font;
+
+/**
+ * Basic data class for test color
+ *
+ **/
+@Getter
+@Setter
+@EqualsAndHashCode
+@AllArgsConstructor
+@NoArgsConstructor
+public class ColorDemoData {
+
+
+    @ExcelProperty("姓名")
+    private String name;
+    @ExcelProperty("年龄")
+    @HeadFontStyle(color = Font.COLOR_RED)
+    private Integer age;
+    @ExcelProperty("性别")
+    private String sex;
+}

fastexcel-test/src/test/java/cn/idev/excel/test/demo/write/WriteWithColorTest.java

@@ -0,0 +1,34 @@
+package cn.idev.excel.test.demo.write;
+
+import cn.idev.excel.EasyExcel;
+import cn.idev.excel.test.util.TestFileUtil;
+import org.junit.jupiter.api.Test;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * Class for testing colors
+ *
+ */
+public class WriteWithColorTest {
+
+
+    @Test
+    public void write() {
+        String fileName = TestFileUtil.getPath() + "simpleWrite" + System.currentTimeMillis() + ".xlsx";
+        EasyExcel.write(fileName, ColorDemoData.class)
+            .sheet("模板")
+            .doWrite(this::data);
+        System.out.println(fileName);
+    }
+
+    private List<ColorDemoData> data() {
+        List<ColorDemoData> list = new LinkedList<>();
+        for (int i = 0; i < 10; i++) {
+            list.add(new ColorDemoData("name" + i, i, "男"));
+        }
+        return list;
+    }
+
+}