package poi;
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;
import java.util.Map.Entry;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
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;
public class Testpoi {
  public static void main(String[] args) {
    Workbook wb =null;
    Sheet sheet = null;
    Row row = null;
    List<Map<String,String>> list = null;
    String cellData = null;
    String filePath = "D:\\test.xlsx";
    String columns[] = {"name","age","score"};
    wb = readExcel(filePath);
    if(wb != null){
      //用來存放表中數據
      list = new ArrayList<Map<String,String>>();
      //獲取第一個sheet
      sheet = wb.getSheetAt(0);
      //獲取最大行數
      int rownum = sheet.getPhysicalNumberOfRows();
      //獲取第一行
      row = sheet.getRow(0);
      //獲取最大列數
      int colnum = row.getPhysicalNumberOfCells();
      for (int i = 1; i<rownum; i++) {
        Map<String,String> map = new LinkedHashMap<String,String>();
        row = sheet.getRow(i);
        if(row !=null){
          for (int j=0;j<colnum;j++){
            cellData = (String) getCellFormatValue(row.getCell(j));
            map.put(columns[j], cellData);
          }
        }else{
          break;
        }
        list.add(map);
      }
    }
    //遍歷解析出來的list
    for (Map<String,String> map : list) {
      for (Entry<String,String> entry : map.entrySet()) {
        System.out.print(entry.getKey()+":"+entry.getValue()+",");
      }
      System.out.println();
    }
  }
  //讀取excel
  public static Workbook readExcel(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 = null;
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
    return wb;
  }
  public static Object getCellFormatValue(Cell cell){
    Object cellValue = null;
    if(cell!=null){
      //判斷cell類型
      switch(cell.getCellType()){
      case Cell.CELL_TYPE_NUMERIC:{
        cellValue = String.valueOf(cell.getNumericCellValue());
        break;
      }
      case Cell.CELL_TYPE_FORMULA:{
        //判斷cell是否為日期格式
        if(DateUtil.isCellDateFormatted(cell)){
          //轉換為日期格式YYYY-mm-dd
          cellValue = cell.getDateCellValue();
        }else{
          //數字
          cellValue = String.valueOf(cell.getNumericCellValue());
        }
        break;
      }
      case Cell.CELL_TYPE_STRING:{
        cellValue = cell.getRichStringCellValue().getString();
        break;
      }
      default:
        cellValue = "";
      }
    }else{
      cellValue = "";
    }
    return cellValue;
  }
}