Apache Cell

输入到电子表格中的任何数据总是存储在一个单元中。我们使用的行和列的标签来识别单元格。本章介绍了如何使用Java编程操纵单元电子表格的数据。

创建一个单元格

需要创建一个单元之前创建一个行。行是什么？只不过是单元的集合。

下面的代码片段用于创建一个单元格。

//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);

单元格类型

单元格类型指定单元格是否可以包含字符串，数值，或公式。字符串单元不能持有数值和数值单元格无法容纳字符串。下面给出是单元格值和类型的语法。

以下代码是用于在电子表格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");}
}

保存上面的代码到一个名为TypesofCells.java文件，编译并从命令提示符如下执行它。

$javac TypesofCells.java
$java TypesofCells

如果您的系统配置了POI库，那么它会编译和执行在当前目录中生成一个名为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。

单元格样式

在这里，可以学习如何做单元格格式，并采用不同的风格，如合并相邻的单元格，添加边框，设置单元格对齐方式和填充颜色。

以下代码是使用Java编程用于不同样式应用到单元格。

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 cellsspreadsheet.addMergedRegion(new CellRangeAddress(1, //first row (0-based)1, //last row (0-based)1, //first column (0-based)4 //last column (0-based)));//CELL Alignmentrow = 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 BORDERrow = 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 colorrow = 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 colorrow = 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");}
}

保存上面的代码在一个名为CellStyle.java文件，编译并从命令提示符如下执行它。

$javac CellStyle.java
$java CellStyle

它会生成一个名为cellstyle.xlsx在当前目录中的Excel文件并显示以下输出。

cellstyle.xlsx written successfully

cellstyle.xlsx文件如下所示。