java 用安全的多线程写导出多个sheet页Excel功能 带有代码注释

以下是一个使用Java多线程导出多个sheet页的Excel示例，带有代码注释：

import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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.ss.usermodel.HorizontalAlignment;

public class ExcelExportService {
    
    // 定义线程池
    private ExecutorService executorService;
    
    // 定义导出数据列表
    private List<List<Object[]>> dataList = new ArrayList<>();
    
    // 定义每个sheet页的标题
    private List<String> sheetTitles = new ArrayList<>();
    
    // 构造函数，初始化线程池
    public ExcelExportService(int threadCount) {
        executorService = Executors.newFixedThreadPool(threadCount);
    }
    
    // 添加导出数据
    public void addData(List<Object[]> data, String sheetTitle) {
        dataList.add(data);
        sheetTitles.add(sheetTitle);
    }
    
    // 导出Excel文件
    public void exportExcel(String filePath) throws Exception {
        // 创建工作簿
        HSSFWorkbook workbook = new HSSFWorkbook();
        
        // 创建样式
        HSSFCellStyle cellStyle = workbook.createCellStyle();
        cellStyle.setAlignment(HorizontalAlignment.CENTER); // 居中对齐
        
        // 创建字体
        HSSFFont font = workbook.createFont();
        font.setBold(true); // 加粗
        cellStyle.setFont(font);
        
        // 循环生成每个sheet页
        for (int i = 0; i < dataList.size(); i++) {
            final int sheetIndex = i;
            executorService.execute(new Runnable() {
                @Override
                public void run() {
                    // 创建sheet页
                    HSSFSheet sheet = workbook.createSheet(sheetTitles.get(sheetIndex));
                    
                    // 获取数据
                    List<Object[]> data = dataList.get(sheetIndex);
                    
                    // 循环生成每行数据
                    for (int rowIndex = 0; rowIndex < data.size(); rowIndex++) {
                        Object[] rowData = data.get(rowIndex);
                        HSSFRow row = sheet.createRow(rowIndex);
                        
                        // 循环生成每个单元格
                        for (int cellIndex = 0; cellIndex < rowData.length; cellIndex++) {
                            row.createCell(cellIndex).setCellValue(rowData[cellIndex].toString());
                        }
                    }
                    
                    // 设置标题行样式
                    sheet.getRow(0).setRowStyle(cellStyle);
                }
            });
        }
        
        // 等待所有线程执行完毕
        executorService.shutdown();
        while (!executorService.isTerminated()) {
            Thread.sleep(100);
        }
        
        // 写入文件
        FileOutputStream fos = new FileOutputStream(filePath);
        workbook.write(fos);
        fos.close();
    }
}

使用方法：

// 创建导出服务
ExcelExportService exportService = new ExcelExportService(10); // 创建10个线程的线程池

// 添加导出数据
List<Object[]> data1 = new ArrayList<>();
data1.add(new Object[] {"姓名", "年龄", "性别"});
data1.add(new Object[] {"张三", 18, "男"});
exportService.addData(data1, "学生");

List<Object[]> data2 = new ArrayList<>();
data2.add(new Object[] {"名称", "价格", "库存"});
data2.add(new Object[] {"手机", 1999, 50});
exportService.addData(data2, "商品");

// 导出Excel文件
exportService.exportExcel("D:\\test.xls");