Here is an example that insert excel file data into mysql database.

import java.io.*;
  import java.sql.*;
  import java.util.*;
  import java.util.regex.*;
  import org.apache.poi.hssf.usermodel.*;
  import org.apache.poi.poifs.filesystem.POIFSFileSystem;

  public class InsertExcelFileData {
  public static void main( String [] args ) {
    String fileName="c:/data.xls";
    Vector dataHolder=read(fileName);
    saveToDatabase(dataHolder);
}
    public static Vector read(String fileName)    {
    Vector cellVectorHolder = new Vector();
    try{
            FileInputStream myInput = new FileInputStream(fileName);
            POIFSFileSystem myFileSystem = new POIFSFileSystem(myInput);
        HSSFWorkbook myWorkBook = new HSSFWorkbook(myFileSystem);
        HSSFSheet mySheet = myWorkBook.getSheetAt(0);
       Iterator rowIter = mySheet.rowIterator(); 
       while(rowIter.hasNext()){
              HSSFRow myRow = (HSSFRow) rowIter.next();
              Iterator cellIter = myRow.cellIterator();
              Vector cellStoreVector=new Vector();
              while(cellIter.hasNext()){
                      HSSFCell myCell = (HSSFCell) cellIter.next();
                      cellStoreVector.addElement(myCell);
              }
              cellVectorHolder.addElement(cellStoreVector);
      }
    }catch (Exception e){e.printStackTrace(); }
    return cellVectorHolder;
}
    private static void saveToDatabase(Vector dataHolder) {
    String name="";
            String address="";
            for (int i=0;i<dataHolder.size(); i++){
               Vector cellStoreVector=(Vector)dataHolder.elementAt(i);
                    for (int j=0; j < cellStoreVector.size();j++){
                            HSSFCell myCell = (HSSFCell)cellStoreVector.elementAt(j);
                            String st = myCell.toString();
                             name=st.substring(0,1);
                             address=st.substring(0);
                                                    }
                    try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root", "root");
    Statement stat=con.createStatement();
    int k=stat.executeUpdate("insert into data(name,address) value('"+name+"','"+address+"')");
    System.out.println("Data is inserted");
    stat.close();
    con.close();
    }
    catch(Exception e){}
    }
    }
  }