Cells

您输入电子表格的任何数据始终存储在单元格中。 我们使用行和列的标签来标识单元格。 本章介绍如何使用Java编程在电子表格中操作单元格中的数据。

创建一个单元格

您需要在创建单元格之前创建一行。 一行只是一组细胞。

以下代码段用于创建单元格。

//create new workbook
XSSFWorkbook workbook = new XSSFWorkbook(); 
//create spreadsheet with a name
XSSFSheet spreadsheet = workbook.createSheet("new sheet");
//create first row on a created spreadsheet
XSSFRow row = spreadsheet.createRow(0);
//create first cell on created row
XSSFCell cell = row.createCell(0);

细胞类型

单元格类型指定单元格是否可以包含字符串，数值或公式。 字符串单元格不能保存数值，而数字单元格不能保存字符串。 下面给出了单元格的类型，它们的值和类型语法。

以下代码用于在电子表格中创建不同类型的单元格。

import java.io.File;
import java.io.FileOutputStream;
import java.util.Date;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class TypesofCells {
   public static void main(String[] args)throws Exception {
      XSSFWorkbook workbook = new XSSFWorkbook(); 
      XSSFSheet spreadsheet = workbook.createSheet("cell types");
      XSSFRow row = spreadsheet.createRow((short) 2);
      row.createCell(0).setCellValue("Type of Cell");
      row.createCell(1).setCellValue("cell value");
      row = spreadsheet.createRow((short) 3);
      row.createCell(0).setCellValue("set cell type BLANK");
      row.createCell(1);
      row = spreadsheet.createRow((short) 4);
      row.createCell(0).setCellValue("set cell type BOOLEAN");
      row.createCell(1).setCellValue(true);
      row = spreadsheet.createRow((short) 5);
      row.createCell(0).setCellValue("set cell type ERROR");
      row.createCell(1).setCellValue(XSSFCell.CELL_TYPE_ERROR );
      row = spreadsheet.createRow((short) 6);
      row.createCell(0).setCellValue("set cell type date");
      row.createCell(1).setCellValue(new Date());
      row = spreadsheet.createRow((short) 7);
      row.createCell(0).setCellValue("set cell type numeric");
      row.createCell(1).setCellValue(20 );
      row = spreadsheet.createRow((short) 8);
      row.createCell(0).setCellValue("set cell type string");
      row.createCell(1).setCellValue("A String");
      FileOutputStream out = new FileOutputStream(new File("typesofcells.xlsx"));
      workbook.write(out);
      out.close();
      System.out.println("typesofcells.xlsx written successfully");
   }
}

将上述代码保存在名为TypesofCells.java的文件中，从命令提示符处编译并执行它，如下所示。

$javac TypesofCells.java
$java TypesofCells

如果您的系统配置了POI库，那么它将编译并执行以在当前目录中生成名为typesofcells.xlsx的Excel文件，并显示以下输出。

typesofcells.xlsx written successfully

typesofcells.xlsx文件如下所示。

细胞样式

在这里，您可以学习如何进行单元格格式化并应用不同的样式，例如合并相邻单元格，添加边框，设置单元格对齐和填充颜色。

以下代码用于使用Java编程将不同样式应用于单元格。

import java.io.File;
import java.io.FileOutputStream;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class CellStyle {
   public static void main(String[] args)throws Exception {
      XSSFWorkbook workbook = new XSSFWorkbook(); 
      XSSFSheet spreadsheet = workbook.createSheet("cellstyle");
      XSSFRow row = spreadsheet.createRow((short) 1);
      row.setHeight((short) 800);
      XSSFCell cell = (XSSFCell) row.createCell((short) 1);
      cell.setCellValue("test of merging");
      //MEARGING CELLS 
      //this statement for merging cells
      spreadsheet.addMergedRegion(
         new CellRangeAddress(
            1, //first row (0-based)
            1, //last row (0-based)
            1, //first column (0-based)
            4 //last column (0-based)
         )
      );
      //CELL Alignment
      row = spreadsheet.createRow(5); 
      cell = (XSSFCell) row.createCell(0);
      row.setHeight((short) 800);
      // Top Left alignment 
      XSSFCellStyle style1 = workbook.createCellStyle();
      spreadsheet.setColumnWidth(0, 8000);
      style1.setAlignment(XSSFCellStyle.ALIGN_LEFT);
      style1.setVerticalAlignment(XSSFCellStyle.VERTICAL_TOP);
      cell.setCellValue("Top Left");
      cell.setCellStyle(style1);
      row = spreadsheet.createRow(6); 
      cell = (XSSFCell) row.createCell(1);
      row.setHeight((short) 800);
      // Center Align Cell Contents 
      XSSFCellStyle style2 = workbook.createCellStyle();
      style2.setAlignment(XSSFCellStyle.ALIGN_CENTER);
      style2.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
      cell.setCellValue("Center Aligned"); 
      cell.setCellStyle(style2);
      row = spreadsheet.createRow(7); 
      cell = (XSSFCell) row.createCell(2);
      row.setHeight((short) 800);
      // Bottom Right alignment 
      XSSFCellStyle style3 = workbook.createCellStyle();
      style3.setAlignment(XSSFCellStyle.ALIGN_RIGHT);
      style3.setVerticalAlignment(XSSFCellStyle.VERTICAL_BOTTOM);
      cell.setCellValue("Bottom Right");
      cell.setCellStyle(style3);
      row = spreadsheet.createRow(8);
      cell = (XSSFCell) row.createCell(3);
      // Justified Alignment 
      XSSFCellStyle style4 = workbook.createCellStyle();
      style4.setAlignment(XSSFCellStyle.ALIGN_JUSTIFY);
      style4.setVerticalAlignment(XSSFCellStyle.VERTICAL_JUSTIFY);
      cell.setCellValue("Contents are Justified in Alignment"); 
      cell.setCellStyle(style4);
      //CELL BORDER
      row = spreadsheet.createRow((short) 10);
      row.setHeight((short) 800);
      cell = (XSSFCell) row.createCell((short) 1);
      cell.setCellValue("BORDER");
      XSSFCellStyle style5 = workbook.createCellStyle();
      style5.setBorderBottom(XSSFCellStyle.BORDER_THICK);
      style5.setBottomBorderColor(IndexedColors.BLUE.getIndex());
      style5.setBorderLeft(XSSFCellStyle.BORDER_DOUBLE);
      style5.setLeftBorderColor(IndexedColors.GREEN.getIndex());
      style5.setBorderRight(XSSFCellStyle.BORDER_HAIR);
      style5.setRightBorderColor(IndexedColors.RED.getIndex());
      style5.setBorderTop(XSSFCellStyle.BIG_SPOTS);
      style5.setTopBorderColor(IndexedColors.CORAL.getIndex());
      cell.setCellStyle(style5);
      //Fill Colors
      //background color
      row = spreadsheet.createRow((short) 10 );
      cell = (XSSFCell) row.createCell((short) 1);
      XSSFCellStyle style6 = workbook.createCellStyle();
      style6.setFillBackgroundColor(HSSFColor.LEMON_CHIFFON.index );
      style6.setFillPattern(XSSFCellStyle.LESS_DOTS);
      style6.setAlignment(XSSFCellStyle.ALIGN_FILL);
      spreadsheet.setColumnWidth(1,8000);
      cell.setCellValue("FILL BACKGROUNG/FILL PATTERN");
      cell.setCellStyle(style6);
      //Foreground color
      row = spreadsheet.createRow((short) 12);
      cell = (XSSFCell) row.createCell((short) 1);
      XSSFCellStyle style7 = workbook.createCellStyle();
      style7.setFillForegroundColor(HSSFColor.BLUE.index);
      style7.setFillPattern( XSSFCellStyle.LESS_DOTS);
      style7.setAlignment(XSSFCellStyle.ALIGN_FILL);
      cell.setCellValue("FILL FOREGROUND/FILL PATTERN");
      cell.setCellStyle(style7);
      FileOutputStream out = new FileOutputStream(new File("cellstyle.xlsx"));
      workbook.write(out);
      out.close();
      System.out.println("cellstyle.xlsx written successfully");
   }
}

将上述代码保存在名为CellStyle.java的文件中，从命令提示符处编译并执行它，如下所示。

$javac CellStyle.java
$java CellStyle

它将在当前目录中生成名为cellstyle.xlsx的Excel文件，并显示以下输出。

cellstyle.xlsx written successfully

cellstyle.xlsx文件如下所示。