2024年鸿蒙最新一个简单易用的Excel导出工具_bladex excelutil(3)，开发人员必学

本文链接：https://blog.youkuaiyun.com/2401_84872028/article/details/138902994

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private static void setHeader(HttpServletResponse response, String fileName) throws Exception {
    response.setContentType("application/vnd.ms-excel");
    String codedFileName = java.net.URLEncoder.encode(fileName , "UTF-8");
    response.setCharacterEncoding("utf-8");
    response.setHeader("content-disposition", "attachment;filename=" + codedFileName+new SimpleDateFormat("yyyyMMddHHmmss ").format(new Date()) + ".xls");
}

private static void setCellHead(HSSFSheet sheet, LinkedHashMap<String, String> fieldMap, HSSFCellStyle headStyle) {

    HSSFRow row1 = sheet.createRow(0);
    //设置行高
    row1.setHeight((short) 500);
    int i = 0;
    for (String colHead : fieldMap.values()) {
        HSSFCell cell = row1.createCell(i);
        cell.setCellValue(colHead);
        cell.setCellStyle(headStyle);
        i++;
    }
}

private static void setCell(HSSFWorkbook wb
        , String fileName
        , LinkedHashMap<String, String> fieldMap
        , List<?> lists
        , HSSFCellStyle headStyle
        , HSSFCellStyle bodyStyle
) throws Exception {
    HSSFSheet sheet = null;
    int j = 0;
    if (lists == null || lists.size() == 0) {
        sheet = wb.createSheet(fileName);
        setCellHead(sheet, fieldMap, headStyle);
        for (int k = 0; k < fieldMap.keySet().size(); k++) {
            sheet.setColumnWidth(k, 20 * 256);
        }
    }else {
        for (int i = 0; i < lists.size(); i++) {
            if (i == 0) {
                sheet = wb.createSheet(fileName);
                setCellHead(sheet, fieldMap, headStyle);
            } else if (i % 30000 == 0) {
                j++;
                sheet = wb.createSheet(fileName + j);
                setCellHead(sheet, fieldMap, headStyle);
            }
            for (int k = 0; k < fieldMap.keySet().size(); k++) {
                sheet.setColumnWidth(k, 20 * 256);
            }
            Object item = lists.get(i);
            HSSFRow row = sheet.createRow(i + 1);
            //设置行高
            row.setHeight((short) 500);
            int x = 0;
            Class itemClazz = lists.get(0).getClass();
            for (String colBody : fieldMap.keySet()) {
                Field field = getFieldByName(colBody, itemClazz);
                field.setAccessible(true);
                HSSFCell c = row.createCell(x);
                if(field.get(item) instanceof  Date){
                    c.setCellValue(field.get(item)!=null?new SimpleDateFormat("yyyy-MM-dd HH:mm").format( field.get(item)):"");
                }else if(field.get(item) == null){
                    c.setCellValue(" ");
                }
                else{
                    c.setCellValue(String.valueOf(field.get(item)));
                }
                c.setCellStyle(bodyStyle);
                x++;
            }
        }
    }
}

private static Field getFieldByName(String fieldName, Class<?> clazz) {
    Field[] selfFields = clazz.getDeclaredFields();
    for (Field field : selfFields) {
        if (field.getName().equals(fieldName)) {
            return field;
        }
    }

    Class<?> superClazz = clazz.getSuperclass();
    if (superClazz != null && superClazz != Object.class) {
        return getFieldByName(fieldName, superClazz);
    }

    //如果本类和父类都没有，则返回空
    return null;
}

private static HSSFWorkbook listToExcel(List<?> lists,
                                        LinkedHashMap<String, String> fieldMap,
                                        String fileName) throws Exception {
    // 创建HSSFWorkbook对象(excel的文档对象)
    HSSFWorkbook hssfWorkbook = new HSSFWorkbook();
    HSSFCellStyle headStyle = getHeadStyle(hssfWorkbook);
    HSSFCellStyle bodyStyle = getBodyStyle(hssfWorkbook);
    setCell(hssfWorkbook, fileName, fieldMap, lists, headStyle, bodyStyle);
    return hssfWorkbook;
}

private static HSSFCellStyle getHeadStyle(HSSFWorkbook hssfWorkbook) {
    HSSFCellStyle headStyle = hssfWorkbook.createCellStyle();
    headStyle.setFillForegroundColor(HSSFColor.PALE_BLUE.index);
    headStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    headStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    headStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    headStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    headStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    headStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    // 纵向居中
    headStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER);

    HSSFFont font = hssfWorkbook.createFont();
    font.setFontName("黑体");
    //设置字体大小
    font.setFontHeightInPoints((short) 12);
    headStyle.setFont(font);
    return headStyle;
}

private static HSSFCellStyle getBodyStyle(HSSFWorkbook hssfWorkbook) {
    HSSFCellStyle bodyStyle = hssfWorkbook.createCellStyle();

    bodyStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    bodyStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    bodyStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
    bodyStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
    bodyStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
    // 纵向居中
    bodyStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER);

    HSSFFont font = hssfWorkbook.createFont();
    font.setFontName("黑体");
    bodyStyle.setFont(font);
    return bodyStyle;
}


/**
 * 传入一个导出的数据源类型，该方法会帮助你拿到  @ApiModelProperty 里面的Value 和 绑定一起的 attributeName
 * 并以Map的形式返回
 * @param apiModelClass         要拿到 @ApiModelProperty value 的类型
 * @param <T>                   改类 的 T
 * @return                      返回一个 Map
 */
public static <T> LinkedHashMap<String, String> getFieldsMap(Class<T> apiModelClass){
    List<ApiModelPropertyFixedTo> fixedVoList = AnnotationTool.getFixedVoList(apiModelClass);
    LinkedHashMap<String, String> linkedHashMap = new LinkedHashMap<>();
    if(CollectionUtils.isEmpty(fixedVoList)) {
        return linkedHashMap;
    }
    fixedVoList.forEach((item)-> {
        // 隐藏的部分不加载

// if (!item.isHidden()){
// linkedHashMap.put(item.getAttributeName(),item.getValue());

网上学习资料一大堆，但如果学到的知识不成体系，遇到问题时只是浅尝辄止，不再深入研究，那么很难做到真正的技术提升。

需要这份系统化的资料的朋友，可以戳这里获取