import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.text.SimpleDateFormat;

import java.util.HashMap;

import java.util.Map;

import javax.swing.JOptionPane;

import org.apache.poi.EncryptedDocumentException;

import org.apache.poi.openxml4j.exceptions.InvalidFormatException;

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.ss.usermodel.WorkbookFactory;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelLog {

    public ExcelLog(int index) {

        createNewBook();

    }

    //新建工作表

    private void createNewBook() {

        try {

            String path = "D:\\test.xlsx";

            File f = new File(path);

            File dir = f.getParentFile();

            if (!dir.exists()) {//如果文件路径不存在，则创建路径

                dir.mkdirs();

            }

            if (!f.exists()) {//如果文件不存在，则新建文件

                Workbook wb = new XSSFWorkbook(); //.xlsx

                Sheet sheet = wb.createSheet("Test Log");  //新建Sheet

                Row row = sheet.createRow(0);  //写一行数据

                String[] header = {"COL1", "COL2", "COL3", "COL4", "COL5"};

                for (int i = 0; i < header.length; i++) {

                    row.createCell(i).setCellValue(header[i]);

                }

                //写入文件

                try (FileOutputStream fileOut = new FileOutputStream(path)) {

                    wb.write(fileOut);

                    wb.close();

                }

            }

        } catch (IOException ex) {

            JOptionPane.showMessageDialog(null, "无法写入Excel文件:" + ex.getMessage());

            System.exit(-1);

        }

    }

   //Sheet表的行数

    private int getRowCount() {

        try (FileInputStream fileInput = new FileInputStream(path)) {

            Workbook wb = WorkbookFactory.create(fileInput);

            Sheet sheet = wb.getSheetAt(0);

            return sheet.getPhysicalNumberOfRows();

        } catch (IOException | InvalidFormatException | EncryptedDocumentException ex) {

            JOptionPane.showMessageDialog(null, "无法读取Excel文件：" + ex.getMessage());

            System.exit(-1);

            return 0;

        }

    }

   //写一行数据

    private void writeLine(String[] items)  {

        try{

            Workbook wb = WorkbookFactory.create(new FileInputStream(path));

            Sheet sheet = wb.getSheetAt(0);

            int rowIndex = this.getRowCount();

            Row row = sheet.createRow(rowIndex);

            for (int i = 0; i < items.length; i++) {

                row.createCell(i).setCellValue(items[i]);

            }

            //写入文件

            try(FileOutputStream fileOut = new FileOutputStream(path);){

                 wb.write(fileOut);

            }

            wb.close();

        } catch (IOException | InvalidFormatException | EncryptedDocumentException ex) {

            ex.printStackTrace();

            JOptionPane.showMessageDialog(null, "无法写入Excel文件：" + ex.getMessage());

            System.exit(-1);

        }

    }

}