How to use annotations to solve the problem that reflection does not guarantee the order of fields
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@ Retention (RetentionPolicy.RUNTIME) @ Target (ElementType.FIELD) public @ interface MyColumn {int columnIndex () default 0 } public class PoiUtil {/ * get the file content list * * @ param file * @ param clazz * @ return * @ throws Exception * / public List getListFromFile (MultipartFile file, Class clazz) throws Exception {/ / finally return data List resultList = new ArrayList (); InputStream is = file.getInputStream () / / create using the factory method. Workbook wb = WorkbookFactory.create (is); Sheet sheet = wb.getSheetAt (0); int totalRowNum = sheet.getLastRowNum (); / / get the total number of columns int cellLength = sheet.getRow (0). GetPhysicalNumberOfCells (); / / get all the fields of the reflection class Field [] fields = clazz.getDeclaredFields (); / / create an array of fields that are in the same order as the excel rows. Field [] newFields = newField [cellLength]; for (int I = 0; I < cellLength; iTunes +) {for (Field field: fields) {Annotation [] annotationArr = field.getDeclaredAnnotations () For (Annotation annotation: annotationArr) {if (annotation instanceof MyColumn) {if (I = = ((MyColumn) annotation) .columnIndex ()) {newFields [I] = field } / / get for from line x (int x = 1; x ='A'& & str.charAt (0)
