在Java中，可以使用Apache POI库来实现Excel的导入和导出功能。以下是一个简单的例子，展示了如何使用Apache POI进行Excel文件的导入和导出。
导入Excel文件：
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
public class ExcelImporter {
public void importExcel(String filePath) throws IOException {
FileInputStream fileInputStream = new FileInputStream(new File(filePath));
Workbook workbook = new XSSFWorkbook(fileInputStream);
Sheet sheet = workbook.getSheetAt(0);
for (Row row : sheet) {
for (Cell cell : row) {
// 根据单元格类型读取数据
switch (cell.getCellTypeEnum()) {
case STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue() + "\t");
break;
case FORMULA:
System.out.print(cell.getCellFormula() + "\t");
break;
default: break;
}
}
System.out.println();
}
workbook.close();
fileInputStream.close();
}
}导出Excel文件：
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.FileOutputStream;
import java.io.IOException;
public class ExcelExporter {
public void exportExcel(String filePath) throws IOException {
Workbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet("Data");
Row row = sheet.createRow(0);
Cell cell = row.createCell(0);
cell.setCellValue("Hello Excel");
FileOutputStream fileOutputStream = new FileOutputStream(filePath);
workbook.write(fileOutputStream);
workbook.close();
fileOutputStream.close();
}
}这两个类提供了基本的导入和导出功能。在实际应用中，你可能需要处理更复杂的Excel文件，例如带有样式、合并单元格、注释等复杂特性的文件。Apache POI提供了丰富的API来处理这些情况。