如何设置索引值以更改每列 header 的颜色以及如何根据 API 请求设置颜色？
How can I set indexed value to change the color of each column header and how to set color from API request?
我想设置 excel 文件中不同列 header 的颜色，那么如何设置索引值来设置每列 header 的颜色并假设如果我从 API 请求中获得 4 种十六进制 (#FFF) 格式的不同颜色，那么如何将这些颜色设置为 4 个不同的列 headers.
这是我的代码：
import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.apache.commons.codec.binary.Hex;
class CreateXSSFColor {
public static void main(String[] args) throws Exception {
try (Workbook workbook = new XSSFWorkbook();
FileOutputStream fileout = new FileOutputStream("Excel.xlsx") ) {
String rgbS = "FFF000";
byte[] rgbB = Hex.decodeHex(rgbS); // get byte array from hex string
XSSFColor color = new XSSFColor(rgbB, null); //IndexedColorMap has no usage until now. So it can be set null.
XSSFCellStyle cellStyle = (XSSFCellStyle) workbook.createCellStyle();
cellStyle.setFillForegroundColor(color);
cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
Sheet sheet = workbook.createSheet();
Row row = sheet.createRow(0);
Cell cell = row.createCell(0);
cell.setCellValue("yellow");
cell.setCellStyle(cellStyle);
workbook.write(fileout);
}
}
}
您显示的代码从十六进制字符串创建了一个 XSSFColor 并创建了一个 XSSFCellStyle 并将 XSSFColor 作为填充颜色。然后它使用 XSSFCellStyle 作为一个单元格的单元格样式。
如果你有 4 个十六进制字符串，它们应该是单元格的填充颜色，那么你需要为 4 XSSFCellStyles 创建 4 XSSFColors，每个 XSSFCellStyle 具有 4 个中的一个XSSFColors 作为填充前景色。然后，您可以将这 4 个不同的 XSSFCellStyle 用作 sheet 中不同单元格的单元格样式。
当然，如果十六进制字符串是动态从外部传入的，那么同一个十六进制字符串可以多次出现。那么你不应该一遍又一遍地创建相同的单元格样式。 Excel 中的单元格样式数量有限制。参见 Excel specifications and limits。
以下示例提供了一种方法setFillForegroundXSSFColor，它将给定的XSSFColor设置为给定XSSFCell的单元格样式中的填充前景色。它并不总是为此创建新的单元格样式。相反，它会检查工作簿中是否已经存在合适的单元格样式，该样式是单元格当前单元格样式加上所需填充前景色的组合。如果是，则使用该单元格样式。只有在没有的情况下，才会创建新的单元格样式。
它还提供了一种方法getRGBFromHexString，它使用org.apache.commons.codec.binary.Hex将十六进制字符串转换为字节数组。这使用字符串操作来支持 RGB 的以下十六进制字符串类型：FFFFFF、FFF、#FFFFFF 和 #FFF.
示例代码：
import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.xssf.usermodel.*;
import org.apache.commons.codec.binary.Hex;
class CreateXSSFCellStyles {
static byte[] getRGBFromHexString(String rgbString) {
byte[] rgb = new byte[3];
if (rgbString.startsWith("#")) rgbString = rgbString.substring(1);
if (rgbString.length() == 3)
rgbString = rgbString.substring(0,1) + rgbString.substring(0,1)
+ rgbString.substring(1,2) + rgbString.substring(1,2)
+ rgbString.substring(2,3) + rgbString.substring(2,3);
System.out.println(rgbString);
try {
rgb = Hex.decodeHex(rgbString);
} catch (Exception ex) {
//decoder exception so byte[] rgb remains empty
}
return rgb;
}
static void setFillForegroundXSSFColor(XSSFCell cell, XSSFColor color, FillPatternType fillPatternType) {
//get original cell style of cell
XSSFCellStyle originalCellStyle = cell.getCellStyle();
//is there a fitting cell style already in workbook?
XSSFWorkbook workbook = cell.getSheet().getWorkbook();
for (int i = 0; i < workbook.getNumCellStyles(); i++) {
XSSFCellStyle cellStyle = workbook.getCellStyleAt(i);
//cell style needs to fit requested fill foreground color and fill pattern type
if (color.equals(cellStyle.getFillForegroundColorColor()) && cellStyle.getFillPattern() == fillPatternType) {
//also cell style needs to fit all other cell style properties of original cell style
if (
cellStyle.getAlignment() == originalCellStyle.getAlignment()
&& cellStyle.getBorderLeft() == originalCellStyle.getBorderLeft()
&& cellStyle.getBorderTop() == originalCellStyle.getBorderTop()
&& cellStyle.getBorderRight() == originalCellStyle.getBorderRight()
&& cellStyle.getBorderBottom() == originalCellStyle.getBorderBottom()
&& cellStyle.getLeftBorderColor() == originalCellStyle.getLeftBorderColor()
&& cellStyle.getTopBorderColor() == originalCellStyle.getTopBorderColor()
&& cellStyle.getRightBorderColor() == originalCellStyle.getRightBorderColor()
&& cellStyle.getBottomBorderColor() == originalCellStyle.getBottomBorderColor()
&& cellStyle.getDataFormat() == originalCellStyle.getDataFormat()
&& cellStyle.getFillBackgroundColor() == originalCellStyle.getFillBackgroundColor()
&& cellStyle.getFont() == originalCellStyle.getFont()
&& cellStyle.getHidden() == originalCellStyle.getHidden()
&& cellStyle.getIndention() == originalCellStyle.getIndention()
&& cellStyle.getLocked() == originalCellStyle.getLocked()
&& cellStyle.getQuotePrefixed() == originalCellStyle.getQuotePrefixed()
&& cellStyle.getReadingOrder() == originalCellStyle.getReadingOrder()
&& cellStyle.getRotation() == originalCellStyle.getRotation()
&& cellStyle.getShrinkToFit() == originalCellStyle.getShrinkToFit()
&& cellStyle.getVerticalAlignment() == originalCellStyle.getVerticalAlignment()
&& cellStyle.getWrapText() == originalCellStyle.getWrapText()
) {
cell.setCellStyle(cellStyle);
System.out.println("fitting cell style found");
return;
}
}
}
//no fitting cell style found, so create a new one
XSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.cloneStyleFrom(originalCellStyle);
cellStyle.setFillForegroundColor(color);
cellStyle.setFillPattern(fillPatternType);
cell.setCellStyle(cellStyle);
System.out.println("new cell style created");
}
public static void main(String[] args) throws Exception {
try (XSSFWorkbook workbook = new XSSFWorkbook();
FileOutputStream fileout = new FileOutputStream("Excel.xlsx") ) {
XSSFCellStyle headerCellStyle = workbook.createCellStyle();
headerCellStyle.setFillForegroundColor(IndexedColors.GREY_50_PERCENT.getIndex());
headerCellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
XSSFFont font = workbook.createFont();
font.setColor(IndexedColors.WHITE.getIndex());
headerCellStyle.setFont(font);
System.out.println(workbook.getNumCellStyles()); // 2 == default + header cell style
XSSFSheet sheet = workbook.createSheet();
XSSFRow row = sheet.createRow(0);
XSSFCell cell;
for (int i = 0; i < 8; i++) {
cell = row.createCell(i);
cell.setCellValue("Header " + (i+1));
cell.setCellStyle(headerCellStyle);
}
String rgbS;
byte[] rgbB;
XSSFColor color;
rgbS = "#FF0000";
cell = sheet.getRow(0).getCell(1);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 3 == default + header cell style + this one new created
rgbS = "0000FF";
cell = sheet.getRow(0).getCell(3);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + one from above + this one new created
rgbS = "#F00";
cell = sheet.getRow(0).getCell(5);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + two from above, none new created
rgbS = "#0000FF";
cell = sheet.getRow(0).getCell(7);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + two from above, none new created
workbook.write(fileout);
}
}
}
我想设置 excel 文件中不同列 header 的颜色，那么如何设置索引值来设置每列 header 的颜色并假设如果我从 API 请求中获得 4 种十六进制 (#FFF) 格式的不同颜色，那么如何将这些颜色设置为 4 个不同的列 headers.
这是我的代码：
import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.apache.commons.codec.binary.Hex;
class CreateXSSFColor {
public static void main(String[] args) throws Exception {
try (Workbook workbook = new XSSFWorkbook();
FileOutputStream fileout = new FileOutputStream("Excel.xlsx") ) {
String rgbS = "FFF000";
byte[] rgbB = Hex.decodeHex(rgbS); // get byte array from hex string
XSSFColor color = new XSSFColor(rgbB, null); //IndexedColorMap has no usage until now. So it can be set null.
XSSFCellStyle cellStyle = (XSSFCellStyle) workbook.createCellStyle();
cellStyle.setFillForegroundColor(color);
cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
Sheet sheet = workbook.createSheet();
Row row = sheet.createRow(0);
Cell cell = row.createCell(0);
cell.setCellValue("yellow");
cell.setCellStyle(cellStyle);
workbook.write(fileout);
}
}
}
您显示的代码从十六进制字符串创建了一个 XSSFColor 并创建了一个 XSSFCellStyle 并将 XSSFColor 作为填充颜色。然后它使用 XSSFCellStyle 作为一个单元格的单元格样式。
如果你有 4 个十六进制字符串，它们应该是单元格的填充颜色，那么你需要为 4 XSSFCellStyles 创建 4 XSSFColors，每个 XSSFCellStyle 具有 4 个中的一个XSSFColors 作为填充前景色。然后，您可以将这 4 个不同的 XSSFCellStyle 用作 sheet 中不同单元格的单元格样式。
当然，如果十六进制字符串是动态从外部传入的，那么同一个十六进制字符串可以多次出现。那么你不应该一遍又一遍地创建相同的单元格样式。 Excel 中的单元格样式数量有限制。参见 Excel specifications and limits。
以下示例提供了一种方法setFillForegroundXSSFColor，它将给定的XSSFColor设置为给定XSSFCell的单元格样式中的填充前景色。它并不总是为此创建新的单元格样式。相反，它会检查工作簿中是否已经存在合适的单元格样式，该样式是单元格当前单元格样式加上所需填充前景色的组合。如果是，则使用该单元格样式。只有在没有的情况下，才会创建新的单元格样式。
它还提供了一种方法getRGBFromHexString，它使用org.apache.commons.codec.binary.Hex将十六进制字符串转换为字节数组。这使用字符串操作来支持 RGB 的以下十六进制字符串类型：FFFFFF、FFF、#FFFFFF 和 #FFF.
示例代码：
import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.xssf.usermodel.*;
import org.apache.commons.codec.binary.Hex;
class CreateXSSFCellStyles {
static byte[] getRGBFromHexString(String rgbString) {
byte[] rgb = new byte[3];
if (rgbString.startsWith("#")) rgbString = rgbString.substring(1);
if (rgbString.length() == 3)
rgbString = rgbString.substring(0,1) + rgbString.substring(0,1)
+ rgbString.substring(1,2) + rgbString.substring(1,2)
+ rgbString.substring(2,3) + rgbString.substring(2,3);
System.out.println(rgbString);
try {
rgb = Hex.decodeHex(rgbString);
} catch (Exception ex) {
//decoder exception so byte[] rgb remains empty
}
return rgb;
}
static void setFillForegroundXSSFColor(XSSFCell cell, XSSFColor color, FillPatternType fillPatternType) {
//get original cell style of cell
XSSFCellStyle originalCellStyle = cell.getCellStyle();
//is there a fitting cell style already in workbook?
XSSFWorkbook workbook = cell.getSheet().getWorkbook();
for (int i = 0; i < workbook.getNumCellStyles(); i++) {
XSSFCellStyle cellStyle = workbook.getCellStyleAt(i);
//cell style needs to fit requested fill foreground color and fill pattern type
if (color.equals(cellStyle.getFillForegroundColorColor()) && cellStyle.getFillPattern() == fillPatternType) {
//also cell style needs to fit all other cell style properties of original cell style
if (
cellStyle.getAlignment() == originalCellStyle.getAlignment()
&& cellStyle.getBorderLeft() == originalCellStyle.getBorderLeft()
&& cellStyle.getBorderTop() == originalCellStyle.getBorderTop()
&& cellStyle.getBorderRight() == originalCellStyle.getBorderRight()
&& cellStyle.getBorderBottom() == originalCellStyle.getBorderBottom()
&& cellStyle.getLeftBorderColor() == originalCellStyle.getLeftBorderColor()
&& cellStyle.getTopBorderColor() == originalCellStyle.getTopBorderColor()
&& cellStyle.getRightBorderColor() == originalCellStyle.getRightBorderColor()
&& cellStyle.getBottomBorderColor() == originalCellStyle.getBottomBorderColor()
&& cellStyle.getDataFormat() == originalCellStyle.getDataFormat()
&& cellStyle.getFillBackgroundColor() == originalCellStyle.getFillBackgroundColor()
&& cellStyle.getFont() == originalCellStyle.getFont()
&& cellStyle.getHidden() == originalCellStyle.getHidden()
&& cellStyle.getIndention() == originalCellStyle.getIndention()
&& cellStyle.getLocked() == originalCellStyle.getLocked()
&& cellStyle.getQuotePrefixed() == originalCellStyle.getQuotePrefixed()
&& cellStyle.getReadingOrder() == originalCellStyle.getReadingOrder()
&& cellStyle.getRotation() == originalCellStyle.getRotation()
&& cellStyle.getShrinkToFit() == originalCellStyle.getShrinkToFit()
&& cellStyle.getVerticalAlignment() == originalCellStyle.getVerticalAlignment()
&& cellStyle.getWrapText() == originalCellStyle.getWrapText()
) {
cell.setCellStyle(cellStyle);
System.out.println("fitting cell style found");
return;
}
}
}
//no fitting cell style found, so create a new one
XSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.cloneStyleFrom(originalCellStyle);
cellStyle.setFillForegroundColor(color);
cellStyle.setFillPattern(fillPatternType);
cell.setCellStyle(cellStyle);
System.out.println("new cell style created");
}
public static void main(String[] args) throws Exception {
try (XSSFWorkbook workbook = new XSSFWorkbook();
FileOutputStream fileout = new FileOutputStream("Excel.xlsx") ) {
XSSFCellStyle headerCellStyle = workbook.createCellStyle();
headerCellStyle.setFillForegroundColor(IndexedColors.GREY_50_PERCENT.getIndex());
headerCellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
XSSFFont font = workbook.createFont();
font.setColor(IndexedColors.WHITE.getIndex());
headerCellStyle.setFont(font);
System.out.println(workbook.getNumCellStyles()); // 2 == default + header cell style
XSSFSheet sheet = workbook.createSheet();
XSSFRow row = sheet.createRow(0);
XSSFCell cell;
for (int i = 0; i < 8; i++) {
cell = row.createCell(i);
cell.setCellValue("Header " + (i+1));
cell.setCellStyle(headerCellStyle);
}
String rgbS;
byte[] rgbB;
XSSFColor color;
rgbS = "#FF0000";
cell = sheet.getRow(0).getCell(1);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 3 == default + header cell style + this one new created
rgbS = "0000FF";
cell = sheet.getRow(0).getCell(3);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + one from above + this one new created
rgbS = "#F00";
cell = sheet.getRow(0).getCell(5);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + two from above, none new created
rgbS = "#0000FF";
cell = sheet.getRow(0).getCell(7);
rgbB = getRGBFromHexString(rgbS);
color = new XSSFColor(rgbB, null);
setFillForegroundXSSFColor(cell, color, FillPatternType.SOLID_FOREGROUND);
System.out.println(workbook.getNumCellStyles()); // 4 == default + header cell style + two from above, none new created
workbook.write(fileout);
}
}
}