將檔案從前端上傳到後端，就不說了，我的文章裡面有上傳的,剛開始寫，如果有問題歡迎批評指正

首先，先說一下用法，因為之前每增加一個匯入模板就要單獨開發，比較浪費時間，所以單獨搞了個通用類，引數有待解析檔案，輸出的類，欄位陣列，開始行數，然後返回一個List

1.我們已經獲取到這個檔案，先獲取檔名的字尾，再根據檔案的字尾選擇用不同的工作簿來解析

public static Workbook judgmentFileType(File file)  throws IOException {
    Workbook wb = null;
String fileName = file.getName();
 
String extension = fileName.lastIndexOf(".") == -1 ? "" : fileName.substring(fileName.lastIndexOf(".") + 1);
    if ("xls".equals(extension)) { // 讀取 office 2003 excel
wb = new HSSFWorkbook(new FileInputStream(file));
} else if ("xlsx".equals(extension)) { // 讀取Office 2007 excel
wb = new XSSFWorkbook(new FileInputStream(file));
 
} else {
        boolean deleteInfo = file.delete();
        if(!deleteInfo){
            throw new BusinessException(MsgType.ERROR.getFlag(), "檔案刪除失敗");
}
        throw new BusinessException(MsgType.ERROR.getFlag(), "不支援的檔案型別");
}
    return wb;
}

2.獲取到工作簿之後，要獲取工作簿裡面表格的內容，先獲取sheet，再獲取物理行數

Workbook wb 
 
= judgmentFileType(file);
//獲取工作簿的sheet
sheet = wb.getSheetAt(0);
for (int i = 0; i < sheet.getPhysicalNumberOfRows(); i++) {
        row = sheet.getRow(i);
        if (row == null) {
            continue;
}
        row = sheet.getRow(i);
        int cells = sheet.getRow(0).getPhysicalNumberOfCells();

for (int j = 0; j < cells; j++) {
    cell = row.getCell(j);
String cellValue = getCellValue(cell);
cellValue = cellValue.replaceAll(" ", "");

3.然後獲取物理行數之後還要再獲取每一個單元格的內容

public static String getCellValue(Cell cell) {
    String value = null;
DecimalFormat df = new DecimalFormat("0");// 格式化 number String // 字元
DecimalFormat nf = new DecimalFormat("###.######");// 格式化數字
if(cell != null){
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_STRING:
                value = cell.getStringCellValue();
                break;
            case Cell.CELL_TYPE_NUMERIC:
                if ("@".equals(cell.getCellStyle().getDataFormatString())) {
                    value = df.format(cell.getNumericCellValue());
} else if ("General".equals(cell.getCellStyle().getDataFormatString())) {
                    value = nf.format(cell.getNumericCellValue());
} else {
                    value = nf.format(cell.getNumericCellValue());
}
                break;
            case Cell.CELL_TYPE_BOOLEAN:
                value = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_BLANK:
                value = "";
                break;
            default:
                value = cell.toString();
}
    }else{
        value = "";
}
    return value;
}

4.然後利用反射將表格中的資料一行存在一個類中，這個類是動態的，先用反射把傳過來的類建立一個出來

Object obj = clazz.newInstance();

然後再獲取這個類的方法名

Field[] fields=clazz.getDeclaredFields();

貼上完整程式碼

public static List analysisExcel(File file, Class clazz, String[] headerFields, int BeginRow) throws IOException{
    Sheet sheet = null;
Row row = null;
Cell cell = null;
List list = new ArrayList();
Workbook wb = judgmentFileType(file);
sheet = wb.getSheetAt(0);
SimpleDateFormat formatter1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat formatter2 = new SimpleDateFormat("yyyy-MM-dd");
    try {
        Map<Integer, String> map = new HashMap<Integer, String>();
        for (int i = BeginRow; i < sheet.getPhysicalNumberOfRows(); i++) {
            row = sheet.getRow(i);
            if (row == null) {
                continue;
}
            row = sheet.getRow(i);
            int cells = sheet.getRow(0).getPhysicalNumberOfCells();
Object obj = clazz.newInstance();
            for (int j = 0; j < cells; j++) {
                cell = row.getCell(j);
String cellValue = getCellValue(cell);
cellValue = cellValue.replaceAll(" ", "");
//用反射修改值
if(PubUtil.isNotEmpty(cellValue)){
                    //獲取方法名
Field[] fields=clazz.getDeclaredFields();
//遍歷方法名，從中找出我們所需要的欄位
for (Field field : fields) {
                        if(headerFields[j].equals(field.getName())){
                            String fieldType = field.getType().getSimpleName();
//每個欄位對應的型別不一樣
if ("String".equals(fieldType)) {
                                Method m = obj.getClass().getMethod(getAttributes(headerFields[j]), String.class);
m.invoke(obj, cellValue.toString());
} else if ("Date".equals(fieldType)) {
                                Date date = null;
                                if(cellValue.length() > 15){
                                    String result = cellValue.substring(0,10)+" "+cellValue.substring(10);
date = formatter1.parse(result);
}else{
                                    date = formatter2.parse(cellValue);
}
                                Method m = obj.getClass().getMethod(getAttributes(headerFields[j]),Date.class);
m.invoke(obj,date);
} else if ("BigDecimal".equals(fieldType)) {
                                Method m = obj.getClass().getMethod(getAttributes(headerFields[j]), BigDecimal.class);
m.invoke(obj, new BigDecimal(cellValue));
}  else {
                                System.out.println("not supper type" + fieldType);
}
                        }
                    }
                }
            }
            list.add(obj);
}
    }  catch (Exception e) {
        e.printStackTrace();
}
    return list;
}

呼叫方法

String[] headerFields = {"id","one","two","three","four"};
List list = ImportUtil.analysisExcel(file,BEntity.class, headerFields,1);