POI对Excel

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;

import org.apache.poi.POIXMLDocument;
import org.apache.poi.hssf.usermodel.HSSFDataFormat;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
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;

public class Utils {

    /**
     * 兼容2003 or 2007，不是根据后缀xls or xlsx
     * Creates the appropriate HSSFWorkbook / XSSFWorkbook from
     *  the given InputStream.
     * Your input stream MUST either support mark/reset, or
     *  be wrapped as a {@link PushbackInputStream}!
     */
    public static Workbook create(InputStream inp) throws IOException, InvalidFormatException {
        // If clearly doesn‘t do mark/reset, wrap up
        if(! inp.markSupported()) {
            inp = new PushbackInputStream(inp, 8);
        }
        
        if(POIFSFileSystem.hasPOIFSHeader(inp)) {
            return new HSSFWorkbook(inp);
        }
        if(POIXMLDocument.hasOOXMLHeader(inp)) {
            return new XSSFWorkbook(OPCPackage.open(inp));
        }
        throw new IllegalArgumentException("Your InputStream was neither an OLE2 stream, nor an OOXML stream");
    }
    
    public static void main(String[] args) {
        try {
            InputStream stream = new FileInputStream("c:/1.xlsx");
            Workbook wb = create(stream);
            Sheet  sheet = wb.getSheetAt(0);
            // 行数(从0开始,相当于最后一行的索引),列数
             int count_row=sheet.getLastRowNum();
             int count_cell=sheet.getRow(0).getPhysicalNumberOfCells();
             System.out.println(count_row + " + " + count_cell);
             String[][] str=new String[count_row][count_cell];
             Cell cell = null;
             Row row=null;
             for (int i = 0; i < count_row; i++) {
                 for (int j = 0; j < count_cell; j++) {
                       row=sheet.getRow(i+1);
                       cell=row.getCell(j);
                       String obj_content="";
                       if (cell == null) {
                           continue;
                       }
                       System.out.println(cell.getCellType() + " " + cell.getCellStyle().getDataFormat() + " " + cell.getCellStyle().getDataFormatString());
                       // + cell.getCellFormula() + " " + cell.getCachedFormulaResultType()
                      
                           if(cell.getCellType()==cell.CELL_TYPE_BLANK) {
                                  obj_content="";
                           }else if(cell.getCellType()==cell.CELL_TYPE_NUMERIC) {
                                       
                                  /**
                                   * yyyy-MM-dd-----    14
                                    yyyy年m月d日---    31
                                    yyyy年m月-------    57
                                    m月d日  ----------    58
                                    HH:mm-----------    20
                                    h时mm分  -------    32
                                   *     Date date = org.apache.poi.ss.usermodel.DateUtil.getJavaDate(value);  
                                   */
                                  System.out.println(HSSFDateUtil.isCellDateFormatted(cell));
                                  if (HSSFDateUtil.isCellDateFormatted(cell)) {
                                          Date date = cell.getDateCellValue();
                                    SimpleDateFormat dateFormat = null;
                                      if (cell.getCellStyle().getDataFormat() == HSSFDataFormat.getBuiltinFormat("m/d/yy")) {
                                          dateFormat = new SimpleDateFormat("yyyy-MM-dd");
                                      } else if (cell.getCellStyle().getDataFormat() == HSSFDataFormat.getBuiltinFormat("h:mm:ss")) {
                                          dateFormat = new SimpleDateFormat("HH:mm:ss");
                                      }
                                       obj_content = dateFormat.format(date);
                                       System.out.println(date + " " + dateFormat.format(date));
                                  } else {
                                      obj_content=(int)cell.getNumericCellValue()+"";
                                  }
                           } else if(cell.getCellType()==cell.CELL_TYPE_STRING) {
                                  obj_content=cell.getStringCellValue();
                           } else if (cell.getCellType()==cell.CELL_TYPE_FORMULA ) {
                               System.out.println("============is fuc" + cell.getCellFormula());
                           } else if (cell.getCellType()==cell.CELL_TYPE_BOOLEAN) {
                               obj_content = String.valueOf(cell.getBooleanCellValue());
                           }
                           else if(cell.getCellType()==cell.CELL_TYPE_ERROR) {
                               
                           }

                           str[i][j]=obj_content;

                    }
             }
             System.out.println(Arrays.deepToString(str));
        } catch (InvalidFormatException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}