<!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>5.2.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>5.2.2</version>
</dependency>
部分需要注意的问题，通过注释的方式写在代码里面了，看代码的时候需要注意下注释
/**
* 设置单元格背景颜色
* <pre>
* 像素、磅、点、缇等各种单位换算参考链接
* https://blog.csdn.net/tanghuan/article/details/113539369
* Excel Cell设置背景颜色参考链接
* https://blog.csdn.net/weixin_43845227/article/details/123580523
* Excel POI Cell背景颜色对照关系表参考链接
* https://blog.csdn.net/lenovo96166/article/details/102765781
* https://www.cnblogs.com/quchunhui/p/14378115.html
* Excel Cell POI Width宽度设置公式参考链接(拟合方程)
* https://blog.csdn.net/duqian42707/article/details/51491312
* https://blog.csdn.net/aosica321/article/details/72320050
* </pre>
*/
public static void setBackgroundColorCellStyle() throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("excel样式设置");
int rowIndex = 0;
for (IndexedColors color : IndexedColors.values()) {
short colorIndex = color.getIndex();
HSSFCellStyle cell1Style = workbook.createCellStyle();
// 设置的背景颜色
cell1Style.setFillForegroundColor(colorIndex);
// 填充效果（全景填充）
cell1Style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
cell1Style.setAlignment(HorizontalAlignment.CENTER);
cell1Style.setVerticalAlignment(VerticalAlignment.CENTER);
HSSFRow row = sheet.createRow(rowIndex++);
row.setHeight((short) (25 * 20));
// 第一列
HSSFCell cell1 = row.createCell(0);
cell1.setCellStyle(cell1Style);
cell1.setCellValue("X:" + colorIndex);
// 第二列
HSSFCellStyle cell2Style = workbook.createCellStyle();
cell2Style.setAlignment(HorizontalAlignment.CENTER);
cell2Style.setVerticalAlignment(VerticalAlignment.CENTER);
HSSFCell cell2 = row.createCell(1);
cell2.setCellStyle(cell2Style);
cell2.setCellValue(color.name());
// 设置列宽
sheet.setColumnWidth(0, 10 * 256 + 185);
sheet.setColumnWidth(1, 35 * 256 + 185);
}
FileOutputStream outputStream = new FileOutputStream("D:/temp/Excel背景颜色列表.xlsx");
workbook.write(outputStream);
outputStream.close();
workbook.close();
}
/**
* 设置背景颜色填充效果
* <pre>
* 背景颜色填充效果参考链接
* https://blog.csdn.net/qq_39541254/article/details/107940224
* </pre>
*/
public static void setFillBackgroundColor() throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("excel填充设置");
int rowIndex = 0;
short colorIndex = IndexedColors.RED.getIndex(); // 选择红色（可参照上图背景色色号） --> 10
// 填充样式
for (FillPatternType patternType : FillPatternType.values()) {
HSSFCellStyle cell1Style = workbook.createCellStyle();
// 设置的背景颜色
cell1Style.setFillForegroundColor(colorIndex);
// 填充效果（全景填充）
cell1Style.setFillPattern(patternType);
// 设置垂直居中
cell1Style.setAlignment(HorizontalAlignment.CENTER);
cell1Style.setVerticalAlignment(VerticalAlignment.CENTER);
// 设置字体
HSSFFont font = workbook.createFont();
// 加粗
font.setBold(true);
cell1Style.setFont(font);
HSSFRow row = sheet.createRow(rowIndex++);
// 设置行高：height = 磅 * 20 （1磅=0.353毫米=20缇）-> POI中行高是"缇(twips)"
row.setHeight((short) (25 * 20));
// 第一列
HSSFCell cell1 = row.createCell(0);
cell1.setCellStyle(cell1Style);
cell1.setCellValue("code:" + patternType.getCode());
HSSFCellStyle cell2Style = workbook.createCellStyle();
// 设置垂直居中
cell2Style.setAlignment(HorizontalAlignment.CENTER);
cell2Style.setVerticalAlignment(VerticalAlignment.CENTER);
// 第二列
HSSFCell cell2 = row.createCell(1);
cell2.setCellStyle(cell2Style);
cell2.setCellValue(patternType.name());
// 设置列宽: width = 256*磅 + 185
sheet.setColumnWidth(0, 10 * 256 + 185);
sheet.setColumnWidth(1, 24 * 256 + 185);
}
FileOutputStream outputStream = new FileOutputStream("D:/temp/Excel背景填充效果.xlsx");
workbook.write(outputStream);
outputStream.close();
workbook.close();
}
/**
* 设置单元格字体样式
*/
public static void setCellFontStyle() throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("excel字体样式");
HSSFCellStyle cellStyle = workbook.createCellStyle();
HSSFFont font = workbook.createFont();
// 字体加粗
font.setBold(true);
// 字体倾斜
font.setItalic(true);
// 字体删除线
font.setStrikeout(true);
// 字体颜色
font.setColor(IndexedColors.YELLOW.getIndex());
// 字体大小:字号
font.setFontHeightInPoints((short) 14);
// 设置行高
// font.setFontHeight((short) 14);
// 字体
font.setFontName("宋体");
cellStyle.setFont(font);
// 设置文字垂直居中
cellStyle.setAlignment(HorizontalAlignment.CENTER);
cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
// 设置单元格内容自动换行（文字超出列宽自动换行）
cellStyle.setWrapText(true);
HSSFRow row = sheet.createRow(0);
HSSFCell cell = row.createCell(0);
cell.setCellStyle(cellStyle);
cell.setCellValue("字体");
row.setHeight((short) (30 * 20));
sheet.setColumnWidth(0, 30 * 256 + 185);
FileOutputStream outputStream = new FileOutputStream("D:/temp/Excel字体样式.xlsx");
workbook.write(outputStream);
outputStream.close();
workbook.close();
}
/**
* 行高列宽设置
*/
public static void setRowHeightAndCellWidth() throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("excel行高、列宽");
// 定义一个5行、5列的数据
int[][] data = {{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}, {11, 12, 13, 14, 15}, {16, 17, 18, 19, 20}, {21, 22, 23, 24, 25}};
for (int rowIndex = 0; rowIndex < data.length; rowIndex++) {
int[] cellData = data[rowIndex];
HSSFRow row = sheet.createRow(rowIndex);
// 行高计算方式：缇(twips) = 磅 * 20 ==> 换算 1磅=20缇
row.setHeight((short) (25 * 20));
for (int cellIndex = 0; cellIndex < cellData.length; cellIndex++) {
HSSFCell cell = row.createCell(cellIndex);
// 列宽计算方式：8磅 * 256 + 185
sheet.setColumnWidth(cellIndex, 8 * 256 + 185);
cell.setCellValue(cellData[cellIndex]);
}
}
FileOutputStream outputStream = new FileOutputStream("D:/temp/Excel行高、列宽.xlsx");
workbook.write(outputStream);
outputStream.close();
workbook.close();
}
/**
* 设置多有边框样式 + 颜色
*/
public static void setAllBorderStyle() throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("excel单元格边框样式");
// ======================= 设置边框
int rowIndex = 0;
for (BorderStyle borderStyle : BorderStyle.values()) {
int cellIndex = 0;
HSSFRow row = sheet.createRow(rowIndex++);
row.setHeight((short) (35 * 20));
// 第一列
HSSFCell cell = row.createCell(cellIndex);
HSSFCellStyle topBorderStyle = workbook.createCellStyle();
// 上边框样式
topBorderStyle.setBorderTop(borderStyle);
cell.setCellValue("设置上边框(" + borderStyle.name() + ")");
cell.setCellStyle(topBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第三列
HSSFCell cell2 = row.createCell(cellIndex);
HSSFCellStyle bottomBorderStyle = workbook.createCellStyle();
// 下边框样式
bottomBorderStyle.setBorderBottom(borderStyle);
cell2.setCellValue("设置下边框(" + borderStyle.name() + ")");
cell2.setCellStyle(bottomBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第五列
HSSFCell cell3 = row.createCell(cellIndex);
HSSFCellStyle leftBorderStyle = workbook.createCellStyle();
// 左边框样式
leftBorderStyle.setBorderLeft(borderStyle);
cell3.setCellValue("设置左边框(" + borderStyle.name() + ")");
cell3.setCellStyle(leftBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第七列
HSSFCell cell4 = row.createCell(cellIndex);
HSSFCellStyle rightBorderStyle = workbook.createCellStyle();
// 左边框样式
rightBorderStyle.setBorderRight(borderStyle);
cell4.setCellValue("设置右边框(" + borderStyle.name() + ")");
cell4.setCellStyle(rightBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
}
// ================= 设置边框并设置颜色
rowIndex += 2;
for (BorderStyle borderStyle : BorderStyle.values()) {
int cellIndex = 0;
HSSFRow row = sheet.createRow(rowIndex++);
row.setHeight((short) (35 * 20));
// 第一列
HSSFCell cell = row.createCell(cellIndex);
HSSFCellStyle topBorderStyle = workbook.createCellStyle();
// 上边框样式
topBorderStyle.setBorderTop(borderStyle);
// 上边框颜色
topBorderStyle.setTopBorderColor(IndexedColors.RED.getIndex());
cell.setCellValue("设置上边框(" + borderStyle.name() + ")");
cell.setCellStyle(topBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第三列
HSSFCell cell2 = row.createCell(cellIndex);
HSSFCellStyle bottomBorderStyle = workbook.createCellStyle();
// 下边框样式
bottomBorderStyle.setBorderBottom(borderStyle);
// 下边框颜色
bottomBorderStyle.setBottomBorderColor(IndexedColors.GREEN.getIndex());
cell2.setCellValue("设置下边框(" + borderStyle.name() + ")");
cell2.setCellStyle(bottomBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第五列
HSSFCell cell3 = row.createCell(cellIndex);
HSSFCellStyle leftBorderStyle = workbook.createCellStyle();
// 左边框样式
leftBorderStyle.setBorderLeft(borderStyle);
// 左边框颜色
leftBorderStyle.setLeftBorderColor(IndexedColors.YELLOW.getIndex());
cell3.setCellValue("设置左边框(" + borderStyle.name() + ")");
cell3.setCellStyle(leftBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
cellIndex += 2;
// 第七列
HSSFCell cell4 = row.createCell(cellIndex);
HSSFCellStyle rightBorderStyle = workbook.createCellStyle();
// 左边框样式
rightBorderStyle.setBorderRight(borderStyle);
// 右边框颜色
rightBorderStyle.setRightBorderColor(IndexedColors.ORANGE.getIndex());
cell4.setCellValue("设置右边框(" + borderStyle.name() + ")");
cell4.setCellStyle(rightBorderStyle);
sheet.setColumnWidth(cellIndex, 35 * 256 + 185);
}
FileOutputStream outputStream = new FileOutputStream("D:/temp/Excel单元格边框样式.xlsx");
workbook.write(outputStream);
outputStream.close();
workbook.close();
}
边框样式对照表，括号内为BorderStyle枚举对象
如果整个Excel中存在空行（整行空），当时若干空行下面存在其他数据，这时候获取到的最终行号就不对了，尤其是存在合并单元格的情况最容易出现这类问题。
很明显10、11、13、14全都是空行了，这时候的lastNum就是不正确的，这种情况要尤为注意。
避免这种情况的出现最直接的一种方式就是，预先知道数据存在多少行，先把所有行都生成sheet.createRow(0)。
同样地，空白的单元格也会出现这种情况，如果单元格不存在或没有样式，获取到的最后一个单元格列数也是不正确的。
像素、磅、点、缇等各种单位换算_点和像素换算_tanghuan的博客-CSDN博客
JAVA对excle创建、读取、设置单元格颜色、背景色、跨行跨列_java设置excel背景色_谷同学的博客-CSDN博客
POI4颜色名称，颜色汉语名称，颜色对应关系_软件工程师文艺的博客-CSDN博客
POI设置Excel单元格背景色（setFillForegroundColor与setFillPattern的使用） - 大墨垂杨 - 博客园
java用POI设置Excel的列宽_sheet.setcolumnwidth_duqian42707的博客-CSDN博客
Java POI 设置Excel单元格的宽度和高度_java poi 设置单元格宽度_aosica的博客-CSDN博客