如何使用Java导出Excel文件 Java操作Excel导出内容方法

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>3.1.5</version> <!--  版本号可能会更新，请查阅最新版本 -->
</dependency>

import com.alibaba.excel.annotation.ExcelProperty;

public class DemoData {
    @ExcelProperty("姓名")
    private String name;
    @ExcelProperty("年龄")
    private Integer age;
    @ExcelProperty("邮箱")
    private String email;

    // getter 和 setter 方法
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

import com.alibaba.excel.EasyExcel;
import java.util.ArrayList;
import java.util.List;

public class ExcelWriter {

    public static void main(String[] args) {
        String fileName = "demo.xlsx"; //  Excel文件名
        List<DemoData> data = new ArrayList<>();
        // 构造一些测试数据
        for (int i = 0; i < 5; i++) {
            DemoData demoData = new DemoData();
            demoData.setName("张三" + i);
            demoData.setAge(20 + i);
            demoData.setEmail("zhangsan" + i + "@example.com");
            data.add(demoData);
        }

        // 写入Excel
        EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(data);

        System.out.println("Excel文件已生成: " + fileName);
    }
}

// 假设 totalData 是你的大数据集
int batchSize = 1000; //  每次写入1000条数据
int total = totalData.size();
for (int i = 0; i < total; i += batchSize) {
    int end = Math.min(i + batchSize, total);
    List<DemoData> batchData = totalData.subList(i, end);
    EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(batchData);
}

import com.alibaba.excel.write.handler.WriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;

import org.apache.poi.ss.usermodel.*;

public class StyleExcelHandler implements WriteHandler {

    @Override
    public void beforeTableCreate(WriteTableHolder writeTableHolder, WriteSheetHolder writeSheetHolder) {
        // 可以设置表格的样式
    }

    @Override
    public void afterTableCreate(WriteTableHolder writeTableHolder, WriteSheetHolder writeSheetHolder) {
        //  表格创建之后的操作
    }

    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, com.alibaba.excel.metadata.data.WriteCellData cellData, HeadData headData, Integer relativeRowIndex, Boolean isHead) {

        Workbook workbook = writeSheetHolder.getSheet().getWorkbook();
        CellStyle cellStyle = workbook.createCellStyle();
        Font font = workbook.createFont();
        font.setBold(true); // 设置字体加粗
        cellStyle.setFont(font);
        cellStyle.setAlignment(HorizontalAlignment.CENTER); // 设置水平居中

        if (isHead) {
            cell.setCellStyle(cellStyle); //  如果是表头，应用样式
        }
    }
}

EasyExcel.write(fileName, DemoData.class).registerWriteHandler(new StyleExcelHandler()).sheet("模板").doWrite(data);