package com.phase;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * Excel导入导出
 * @Author: guandezhi
 * @Date: 2019/3/9 9:47
 */
public class ExcelUtil {

    /**
     * 从excel中读内容
     *
     * @param filePath
     * @param sheetIndex
     * @return
     */
    public static List<Map<String, String>> readExcel(String filePath, Integer sheetIndex) {
        List<Map<String, String>> dataList = new ArrayList<>();
        Workbook wb = ExcelUtil.createWorkBook(filePath);
        if (wb != null) {
            Sheet sheet = wb.getSheetAt(sheetIndex);
            int maxRownum = sheet.getPhysicalNumberOfRows();
            Row firstRow = sheet.getRow(0);
            int maxColnum = firstRow.getPhysicalNumberOfCells();
            String columns[] = new String[maxColnum];
            for (int i = 0; i < maxRownum; i++) {
                Map<String, String> map = null;
                if (i > 0) {
                    map = new LinkedHashMap<>();
                    firstRow = sheet.getRow(i);
                }
                if (firstRow != null) {
                    String cellData = null;
                    for (int j = 0; j < maxColnum; j++) {
                        cellData = (String) ExcelUtil.getCellFormatValue(firstRow.getCell(j));
                        if (i == 0) {
                            columns[j] = cellData;
                        } else {
                            map.put(columns[j], cellData);
                        }
                    }
                } else {
                    break;
                }
                if (i > 0) {
                    dataList.add(map);
                }
            }
        }
        return dataList;
    }

    private static Workbook createWorkBook(String filePath) {
        Workbook wb = null;
        if (filePath == null) {
            return null;
        }
        String extString = filePath.substring(filePath.lastIndexOf("."));
        InputStream is = null;
        try {
            is = new FileInputStream(filePath);
            if (".xls".equals(extString)) {
                return wb = new HSSFWorkbook(is);
            } else if (".xlsx".equals(extString)) {
                return wb = new XSSFWorkbook(is);
            } else {
                return wb;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return wb;
    }

    /**
     * 将字段转为相应的格式
     *
     * @param cell
     * @return
     */
    private static Object getCellFormatValue(Cell cell) {
        Object cellValue = null;
        if (cell != null) {
            //判断cell类型
            switch (cell.getCellType()) {
                case Cell.CELL_TYPE_NUMERIC: {
                    double numericCellValue = cell.getNumericCellValue();
                    cellValue = String.valueOf(Double.valueOf(numericCellValue).intValue());
                    break;
                }
                case Cell.CELL_TYPE_FORMULA: {
                    if (DateUtil.isCellDateFormatted(cell)) {
                        cellValue = cell.getDateCellValue();////转换为日期格式YYYY-mm-dd
                    } else {
                        cellValue = String.valueOf(cell.getNumericCellValue()); //数字
                    }
                    break;
                }
                case Cell.CELL_TYPE_STRING: {
                    cellValue = cell.getRichStringCellValue().getString();
                    break;
                }
                default:
                    cellValue = "";
            }
        } else {
            cellValue = "";
        }
        return cellValue;
    }

}