javapoi导入excel工具类

下面是使用Apache POI导入Excel的Java工具类示例：

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelUtils {

    /**
     * 读取Excel文件，返回一个二维数组
     * 
     * @param filePath Excel文件路径
     * @param sheetName 工作表名称
     * @return 二维数组
     * @throws IOException
     */
    public static String[][] readExcel(String filePath, String sheetName) throws IOException {
        Workbook workbook = null;
        InputStream inputStream = new FileInputStream(filePath);
        if (filePath.endsWith(".xls")) {
            workbook = new HSSFWorkbook(inputStream);
        } else if (filePath.endsWith(".xlsx")) {
            workbook = new XSSFWorkbook(inputStream);
        } else {
            throw new RuntimeException("不支持的文件格式");
        }
        Sheet sheet = workbook.getSheet(sheetName);
        int rowCount = sheet.getPhysicalNumberOfRows();
        int columnCount = sheet.getRow(0).getPhysicalNumberOfCells();
        String[][] data = new String[rowCount - 1][columnCount];
        for (int i = 1; i < rowCount; i++) {
            Row row = sheet.getRow(i);
            for (int j = 0; j < columnCount; j++) {
                Cell cell = row.getCell(j);
                data[i - 1][j] = cell.toString();
            }
        }
        workbook.close();
        inputStream.close();
        return data;
    }
}

使用示例:

String filePath = "path/to/excel/file.xlsx";
String sheetName = "Sheet1";
String[][] data = ExcelUtils.readExcel(filePath, sheetName);