Java POI Excel

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

public class POISample{
  public static void main(String[] args){
    FileInputStream in = null;
    HSSFWorkbook workbook = null;

    try{
      in = new FileInputStream("sample.xls");
      POIFSFileSystem fs = new POIFSFileSystem(in);
      workbook = new HSSFWorkbook(fs);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try{
        in.close();
      }catch (IOException e){
        System.out.println(e.toString());
      }
    }

    workbook.cloneSheet(0);
    workbook.cloneSheet(1);

    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}