java - 使用 Apache POI 获取/修改一个或多个 Excel 工作表中的单元格值

Question

我有一个用 Java 编写的小型应用程序，它使用 Apache POI 来读取/修改 Excel 文档中的值。我使用工作表名称引用单元格，例如工作表“Sheet1”中的单元格 A1，我使用“Sheet1!A1”。

应用程序从命令行运行，带有三个参数:文档名称、包含我要替换的值的单元格、我想要从中获取输出的单元格。

示例:ReadExcel test.xls Sheet1!B2=10;Sheet1!B3=20 Sheet1!B7

上面的例子运行良好。

问题是当我想修改单元格或从另一张工作表获取输出时。

示例:ReadExcel test.xls Sheet1!B2=10;Sheet1!B3=20 Sheet2!B2

我的代码如下:

package poitest;

import java.util.List;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.CellReference;
import org.apache.poi.ss.usermodel.*;

public class ReadExcel {
    public static void main(String[] args) throws FileNotFoundException, IOException {
        // Will contain cell name / value pair for input cells          
        Map<String, String> inputCellsMap = new HashMap<String, String>();

        // Will contain cell name for output cells
        List<String> outputCells = new ArrayList<String>();

        // Open the Excel file
        FileInputStream file = new FileInputStream(new File(args[0]));

        // Get the current workbook
        HSSFWorkbook workbook = new HSSFWorkbook(file);

        // Get the first sheet of the workbook
        HSSFSheet sheet = workbook.getSheetAt(0);

        // Get the input cells that need to be modified and
        // store their name and value in the inputCellsMap
        for (String element : args[1].split(";")) {
            inputCellsMap.put(element.split("=")[0], element.split("=")[1]);
        }

        // Get the output cells that will be accessed for resulting values
        for (String element : args[2].split(";")) {
            outputCells.add(element);           
        }

        // Loop through the cells that need to be modified and 
        // set the new value in the Excel document
        Iterator<Entry<String,String>> inputIterator = inputCellsMap.entrySet().iterator();
        while (inputIterator.hasNext()) {
            Map.Entry<String,String> inputEntry = (Map.Entry<String,String>) inputIterator.next();

            CellReference cellReferenceInput = new CellReference(inputEntry.getKey());
            int cellReferenceInputRow = cellReferenceInput.getRow();
            int cellReferenceInputColumn = cellReferenceInput.getCol();

            Row rowInput = sheet.getRow(cellReferenceInputRow);
            if (rowInput == null)
                rowInput = sheet.createRow(cellReferenceInputRow);
            Cell cellInput = rowInput.getCell(cellReferenceInputColumn, Row.CREATE_NULL_AS_BLANK);              
            cellInput.setCellValue(Integer.parseInt(inputEntry.getValue()));        
        }

        // Apply all formulas after altering cell values
        HSSFFormulaEvaluator.evaluateAllFormulaCells(workbook);

        // Get the results from the output cells
        for (int i = 0; i < outputCells.size(); i++) {
            CellReference cellReferenceOutput = new CellReference(outputCells.get(i));
            int cellReferenceOutputRow = cellReferenceOutput.getRow();
            int cellReferenceOutputColumn = cellReferenceOutput.getCol();

            Row rowOutput = sheet.getRow(cellReferenceOutputRow);
            Cell cellOutput = rowOutput.getCell(cellReferenceOutputColumn, Row.CREATE_NULL_AS_BLANK);

            // Display results
            System.out.println(cellOutput.getNumericCellValue());                       
        }           

        workbook.close();       
    }
}

Answer 1

如果你看看 CellReference 的最长构造函数，您会注意到引用包含 5 个属性:

• 字符串sheetName(可以为空)
• 整数行
• int 列
• boolean 行绝对
• boolean 值 colAbsolute

您的命令行参数包括工作表名称，但您没有使用它。

首先，从代码中删除以下行:HSSFSheet Sheet = workbook.getSheetAt(0);

相反，您需要使用 getSheet(String) 按名称查找工作表。 ，在您创建 CellReference 之后:

HSSFSheet sheet = workbook.getSheet(cellReferenceInput.getSheetName());

HSSFSheet sheet = workbook.getSheet(cellReferenceOutput.getSheetName());