【Java工具四】Java通用Excel导入

怼烎@ 2022-05-21 04:27 256阅读 0赞

package com.zhengtoon.enforcelaw.utils;
    
    import com.zhengtoon.enforcelaw.dto.ElUserInfoDTO;
    import org.apache.commons.lang3.reflect.FieldUtils;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.ss.usermodel.Cell;
    import org.apache.poi.ss.usermodel.Row;
    import org.apache.poi.ss.usermodel.Sheet;
    import org.apache.poi.ss.usermodel.Workbook;
    import org.apache.poi.xssf.usermodel.XSSFWorkbook;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    import java.io.FileInputStream;
    import java.io.InputStream;
    import java.lang.reflect.Field;
    import java.text.DecimalFormat;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    
    public class ImportExcelFileUtil {
        private static final Logger log = LoggerFactory.getLogger(ImportExcelFileUtil.class);
        private final static String excel2003L =".xls";    //2003- 版本的excel
        private final static String excel2007U =".xlsx";   //2007+ 版本的excel
    
        /**
         * 拼装单个obj  通用
         *
         * @param obj
         * @param row
         * @return
         * @throws Exception
         */
        private  static Map<String, Object> dataObj(Object obj, Row row) throws Exception {
            Class<?> rowClazz= obj.getClass();
            Field[] fields = FieldUtils.getAllFields(rowClazz);
            if (fields == null || fields.length < 1) {
                return null;
            }
    
            //容器
            Map<String, Object> map = new HashMap<String, Object>();
    
            //注意excel表格字段顺序要和obj字段顺序对齐 （如果有多余字段请另作特殊下标对应处理）
            for (int j = 0; j < fields.length; j++) {
                map.put(fields[j].getName(), getVal(row.getCell(j)));
            }
            return map;
        }
    
        /**
         * 处理val
         *
         * @param cell
         * @return
         */
        public static String getVal(Cell cell) {
            Object value = null;
            DecimalFormat df = new DecimalFormat("0");  //格式化字符类型的数字
            SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");  //日期格式化
            DecimalFormat df2 = new DecimalFormat("0.00");  //格式化数字
            switch (cell.getCellType()) {
                case Cell.CELL_TYPE_STRING:
                    value = cell.getRichStringCellValue().getString();
                    break;
                case Cell.CELL_TYPE_NUMERIC:
                    if ("General".equals(cell.getCellStyle().getDataFormatString())) {
                        value = df.format(cell.getNumericCellValue());
                    } else if ("m/d/yy".equals(cell.getCellStyle().getDataFormatString())) {
                        value = sdf.format(cell.getDateCellValue());
                    } else {
                        value = df2.format(cell.getNumericCellValue());
                    }
                    break;
                case Cell.CELL_TYPE_BOOLEAN:
                    value = cell.getBooleanCellValue();
                    break;
                case Cell.CELL_TYPE_BLANK:
                    value = "";
                    break;
                default:
                    break;
            }
            return value.toString();
        }
    
        /**
         * * 读取出filePath中的所有数据信息
         *
         * @param filePath excel文件的绝对路径
         * @param obj
         * @return
         */
        public static List<Map<String, Object>> getDataFromExcel(String filePath, Object obj){
    
            if (null == obj) {
                return null;
            }
    
            List<Map<String, Object>> ret = null;
            FileInputStream fis =null;
            Workbook wookbook = null;
            int lineNum = 0;
            Sheet sheet = null;
            try{
                //获取一个绝对地址的流
                fis = new FileInputStream(filePath);
                wookbook = getWorkbook(fis,filePath);
                //得到一个工作表
                sheet = wookbook.getSheetAt(0);
                //获得表头
                Row rowHead = sheet.getRow(0);
                //列数
                int rows = rowHead.getPhysicalNumberOfCells();
                //行数
                lineNum = sheet.getLastRowNum();
                if (0 == lineNum) {
                    log.info("ImportExcelFileUtil中的getDataFromExcel方法导入的Excel内没有数据！");
                    return null;
                }
                ret = getData(sheet, lineNum, rows, obj);
            } catch (Exception e){
                e.printStackTrace();
            }
    
            return ret;
        }
    
        /**
         * 封装获取的对象信息
         *
         * @param sheet
         * @param lineNum
         * @param rowNum
         * @param obj
         * @return
         */
        public static List<Map<String, Object>>  getData(Sheet sheet, int lineNum, int rowNum, Object obj){
            List<Map<String, Object>> ret = null;
            try {
                //容器
                ret = new ArrayList<Map<String, Object>>();
                //获得所有数据
                for (int i = 1; i <= lineNum; i++) {
                    //获得第i行对象
                    Row row = sheet.getRow(i);
                    if (row!=null) {
                        //装载obj
                        ret.add(dataObj(obj,row));
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return ret;
        }
    
        /**
         * 描述：根据文件后缀，自适应上传文件的版本
         *
         * @param inStr,fileName
         * @return
         * @throws Exception
         */
        public static Workbook getWorkbook(InputStream inStr, String fileName) throws Exception{
            Workbook wb = null;
            String fileType = fileName.substring(fileName.lastIndexOf("."));
            if (excel2003L.equals(fileType)) {
                wb = new HSSFWorkbook(inStr);  //2003-
            } else if (excel2007U.equals(fileType)) {
                wb = new XSSFWorkbook(inStr);  //2007+
            } else {
                throw new Exception("解析的文件格式有误！");
            }
            return wb;
        }

public static void main(String[] args) throws Exception{
        ElUserInfoDTO dto = new ElUserInfoDTO();
        //实体类的属性要与Excel中的行数保持一致。本人之前就栽在这，我在实体类里实现Serializable并生成了serialVersionUID，
        //和excel中的行数不一致。
        List<Map<String, Object>> dataFromExcel = getDataFromExcel("D:\\img\\测试4.xls", dto);
        for (int i = 0; i < dataFromExcel.size(); i++) {
            for (Map.Entry<String, Object> entry : dataFromExcel.get(i).entrySet()) {
                System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());
            }
        }
        System.out.println(dataFromExcel);
    }

}

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