NIO-F3-Java/youchain-system/src/main/java/com/youchain/utils/FastExcelUtils.java

package com.youchain.utils;

import cn.idev.excel.FastExcel;
import cn.idev.excel.write.metadata.style.WriteCellStyle;
import cn.idev.excel.write.metadata.style.WriteFont;
import cn.idev.excel.write.style.HorizontalCellStyleStrategy;
import com.youchain.exception.BadRequestException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.MediaTypeFactory;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import static cn.hutool.core.util.CharsetUtil.UTF_8;

@Slf4j
public class FastExcelUtils {

    /**
     * 设置下载文件消息头
     *
     * @param response 响应
     * @param fileName 文件名
     * @param fileSize 文件大小
     */
    public static void setDownloadFileHeader(HttpServletResponse response, String fileName, Long fileSize) {
        response.setCharacterEncoding(UTF_8);
        if (fileSize != null) {
            response.setHeader(HttpHeaders.CONTENT_LENGTH, String.valueOf(fileSize));
        }

        if (StringUtils.isNotEmpty(fileName)) {
            response.setHeader(HttpHeaders.CONTENT_TYPE, MediaTypeFactory.getMediaType(fileName).orElse(MediaType.APPLICATION_OCTET_STREAM) + ";charset=utf-8");
            try {
                response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + URLEncoder.encode(fileName, UTF_8).replaceAll("\\+", "%20"));
            } catch (UnsupportedEncodingException e) {
                throw new RuntimeException(e);
            }
            response.setHeader(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, HttpHeaders.CONTENT_DISPOSITION);
        }
    }

    /**
     * 获取样式
     *
     * @return horizontalCellStyleStrategy
     */
    public static HorizontalCellStyleStrategy getHorizontalCellStyleStrategy() {

        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        headWriteCellStyle.setFillForegroundColor(IndexedColors.SKY_BLUE.getIndex());

        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setFontName("宋体");
        headWriteFont.setColor(IndexedColors.WHITE.getIndex());
        headWriteCellStyle.setWriteFont(headWriteFont);

        WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
        contentWriteCellStyle.setFillForegroundColor(IndexedColors.BLACK.getIndex());

        return new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
    }

    /**
     * 通用单sheet导出
     */
    public static void exportExcel(HttpServletResponse response, String fileName, String sheetName, Class head, Collection<?> data) throws IOException {
        // 设置下载消息头
        setDownloadFileHeader(response, fileName, null);
        //样式
        HorizontalCellStyleStrategy horizontalCellStyleStrategy = getHorizontalCellStyleStrategy();
        // 下载
        FastExcel.write(response.getOutputStream(), head)
                .autoCloseStream(Boolean.FALSE)
                .sheet(sheetName)
                .registerWriteHandler(horizontalCellStyleStrategy)
                .doWrite(data);
    }

    /**
     * 从 Excel 文件中读取指定类型的数据
     *
     * @param file  上传的 Excel 文件
     * @param clazz 数据映射的类（如 Template1.class）
     * @param <T>   数据类型
     * @return 解析后的数据列表
     */
    public static <T> List<T> readExcelData(MultipartFile file, Class<T> clazz, int sheetNo, int headRowNumber) {
        List<T> dataList;
        try {
            dataList = FastExcel.read(file.getInputStream()).head(clazz)
                    .sheet(sheetNo)
                    .headRowNumber(headRowNumber)
                    .doReadSync();
        } catch (IOException e) {
            throw new BadRequestException("数据格式存在问题，无法读取");
        }
        if (CollectionUtils.isEmpty(dataList)) {
            throw new BadRequestException("数据为空");
        }
        return dataList;
    }


    /**
     * 读取Excel文件中指定位置的单元格值
     *
     * @param file   Excel文件
     * @param reader 指定行和列
     */
    public static Map<String, String> readExcelCellValues(MultipartFile file, FastExcelCellListener reader) {
        try {
            FastExcel.read(file.getInputStream(), reader)
                    .sheet()
                    .doReadSync();
        } catch (IOException e) {
            throw new BadRequestException("Excel文件读取失败，请检查文件格式是否正确");
        }
        return reader.getAllCellValues();
    }

    /**
     * 读取 Excel 指定目录指定行
     *
     * @param file Excel 文件
     * @return 回返指定目录指定行返回的内容
     */
    public static List<String> readHeadContent(MultipartFile file, int sheetNo, int headRowNumber) {
        List<Object> data;
        try {
            data = FastExcel.read(file.getInputStream())
                    .sheet(sheetNo)
                    .headRowNumber(headRowNumber)
                    .doReadSync();
        } catch (IOException e) {
            throw new BadRequestException("Excel 文件读取失败: " + e.getMessage());
        }

        // 检查是否有数据
        if (CollectionUtils.isEmpty(data)) {
            throw new BadRequestException("数据为空");
        }

        // 获取并验证首行数据
        Object firstRow = data.get(0);
        if (!(firstRow instanceof Map)) {
            throw new BadRequestException("读取Excel头部内容格式异常");
        }

        // 将头部内容转换为字符串列表
        Map<?, ?> rowMap = (Map<?, ?>) firstRow;
        return rowMap.values().stream()
                .map(value -> value == null ? "" : value.toString())
                .collect(Collectors.toList());

    }
}