尝试使用Apache POI读取Excel文件时，无法将输出写入System.out

Question

我的Java代码遇到了一些问题。我使用NetBeans 8.0.1。

我正在尝试读取包含多张工作表的Excel文件，然后将读数打印到输出窗口。代码中的某些东西不允许打印。我添加了一个for循环以循环覆盖 - 这会起作用吗？

此外，我一直在寻找如何将读数打印成.txt文件，但我无法找到它的相关信息。有人能帮助我吗？

这是我的代码：

package read_write_excel_v2;

import java.io.IOException;
import java.util.Iterator;
import javax.swing.JOptionPane;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.openxml4j.opc.OPCPackage;
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.xssf.usermodel.XSSFWorkbook;


public class JIA_ReadingRewritingWorbooks_v5 {

    public static String GetFileExtension(String path2){
        String pathName = path2;
        String path = "";
        String ext = "";
        int mid = pathName.lastIndexOf(".");
        path = pathName.substring(0, mid);
        ext = pathName.substring(mid + 1, pathName.length());
        return ext;
   }

    /**
     * Excel 2007 (and newer) file reader function. Uses Apache POI. Returns            excel content
     * @throws org.apache.poi.openxml4j.exceptions.InvalidFormatException
     * @throws java.io.IOException
     */
    public static void main(String[] args) throws IOException, InvalidFormatException { 
        String ExcelPath;
        //ExcelPath = JOptionPane.showInputDialog(null, "Enter Excel path: ");
        ExcelPath = "ExcelJAVAWrite_demo.xlsx";

        try{
            // OPCPackage eats less memory than a InputStream, which requires
            // more memory
            OPCPackage pkg;
            pkg = OPCPackage.open(ExcelPath);
            XSSFWorkbook wb = new XSSFWorkbook(pkg);       // Declare XSSF WB
            String fileExtn = GetFileExtension(ExcelPath);
            //Sheet sheet = null;

            for(int i = 0; i < wb.getNumberOfSheets(); i++){
                Sheet sheet = wb.getSheetAt(i);

                // Iteration of rows - rows are ready from the sheet
                Iterator<Row> rows = sheet.rowIterator();

                while(rows.hasNext()){
                    Row row = (Row) rows.next();

                    Iterator<Cell> cells = row.cellIterator();

                    while(cells.hasNext()){
                        Cell cell = (Cell) cells.next();

                        // Ready with the iteration of cells
                        // Now we get the cell type and display the values                    
                        switch(cell.getCellType()){
                            case Cell.CELL_TYPE_BLANK:
                                System.out.print(cell.getStringCellValue() + "\t");
                                break;

                            case Cell.CELL_TYPE_BOOLEAN:
                                System.out.print(cell.getBooleanCellValue() + "\t");
                                break;

                            case Cell.CELL_TYPE_ERROR:
                                System.out.print(cell.getErrorCellValue() + "\t");
                                break;

                            case Cell.CELL_TYPE_FORMULA:
                                System.out.print(cell.getCellFormula());
                                break;
                            default:
                                System.out.println();

                            case Cell.CELL_TYPE_NUMERIC:
                                if(DateUtil.isCellDateFormatted(cell)){
                                    System.out.print(cell.getDateCellValue() + "\t");
                                } else {
                                    System.out.print(cell.getNumericCellValue() + "\t");
                                }
                                break;

                            case Cell.CELL_TYPE_STRING:
                                System.out.print(cell.getRichStringCellValue().getString() + "\t");
                                break;                            
                        }
                    } 
                    System.out.println("");
                } 
            }
            //wb.write(pkg);
            pkg.close();
            System.out.println("Excel file written successfully on screen");
        }
        catch ( IOException ex ) {
            ex.printStackTrace();
        }
    }
}