Here is my requirement, I want to read the records from a .xlsx file and store that records in database table. I tried like this

public class StoreFile {
    public int storeFileRecords(String saveFile,ServletContext application){
        Connection con=null;
        Statement st=null;
        Properties props=null;
        String bytesToString=null;
        try {
            props=new Properties();
            props.load(application.getResourceAsStream("databasedetails.properties"));
            String url=props.getProperty("url");
            String userName=props.getProperty("userName");
            String password=props.getProperty("password");
            String driverClassName=props.getProperty("driverClassName");

                Class.forName(driverClassName);
                con = DriverManager.getConnection(url,userName,password);
                st=con.createStatement();
                FileInputStream fstream = new FileInputStream(saveFile);
                DataInputStream din = new DataInputStream(fstream);
                BufferedReader br = new BufferedReader(new InputStreamReader(din));
                String strLine;
                ArrayList<String> list=new ArrayList<String>();
                while ((strLine = br.readLine()) != null){
                    if(saveFile.endsWith(".xlsx")){
                        byte[] b=strLine.getBytes();
                        System.out.println("b: "+b);
                        bytesToString=new String(b);
                        System.out.println("bytesToString: "+bytesToString);
                        list.add(strLine);
                    }else{
                        strLine=strLine.toString();
                        System.out.println("strLine: "+strLine);
                        list.add(strLine);
                    }
                }
                Iterator<String> itr=null;
                System.out.println("list: "+list);
                int k=0;
                for (itr=list.iterator(); itr.hasNext(); ){
                    String str=itr.next().toString();
                    String [] splitSt=null;
                    if(saveFile.endsWith(".csv"))
                        splitSt =str.split(",");
                    if(saveFile.endsWith(".txt"))
                        splitSt =str.split(" ");
                    if(saveFile.endsWith(".xlsx"))
                        splitSt =str.split(",");
                    String id=splitSt[0];
                    String name=splitSt[1];
                    String age=splitSt[2];
                    System.out.println("id: "+id);
                    System.out.println("name: "+name);
                    System.out.println("age: "+age);
                    String query="insert into student values("+id.trim()+",'"+name.trim()+"',"+age.trim()+")";
                    System.out.println("query: "+query);
                    if(id.equalsIgnoreCase("sid")) continue;                
                    k+=st.executeUpdate(query);
                }               
                return k;
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return 0;
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return 0;
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return 0;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return 0;
            }
            finally{
                try {
                    st.close();
                    con.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }               
            }
    }   
}

Here the problem is after reading the records line by line the data is not converted to String. And i want to know what is the default seperator of xlsx file. Which seperator we have to use in case of xlsx file. I have used , as a seperator.