Question

I have managed bean connected to database. Can you show me how to display the rows of the table USERS from the database?

This is the Bean:

/**     
 Description
 * Bean for checking users and passwords.
The password is converted into SHA-256 hash
 and compared with the hash from a database.
 If the check is successful the user is
 redirected to sr.xhtml page */

package com.dx.sr_57;
/** include default packages for Beans */
import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
   // or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/** include package for SHA-256 encryption */
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/** SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import javax.annotation.Resource;
   // or import javax.faces.bean.ManagedBean;   


@Named("loginController")
@SessionScoped
public class user_check implements Serializable {
    private String user;
    private String password;    

       public user_check(){
       }

       /** Call the Oracle JDBC Connection driver */
       @Resource(name="java:/Oracle")
       private DataSource ds;

       /** get the content of the variables from the JSF Login page */
       public void setUser(String newValue) { 
           user = newValue; 
       }

       public String getUser(){
           return user;       
       }

       public void setPassword(String newValue) { 
           password = newValue; 
       } 

       public String getPassword(){
           return password;
       }

       /** method for converting simple string into SHA-256 hash */
       public String string_hash(String hash) throws NoSuchAlgorithmException{

            MessageDigest md = MessageDigest.getInstance("SHA-256");
            md.update(hash.getBytes());

            byte byteData[] = md.digest();

            /** convert the byte to hex format */
            StringBuilder sb = new StringBuilder();
                for (int i = 0; i < byteData.length; i++) {
            sb.append(Integer.toString((byteData[i] & 0xff) + 0x100, 16).substring(1));
            }              
           return sb.toString();
       }

       /** method for checking password into the Oracle database */
       public String CheckUserDB(String userToCheck) throws SQLException {
            String storedPassword = null;
            if (ds == null) throw new SQLException("No data source");      
       Connection conn = ds.getConnection();
            if (conn == null) throw new SQLException("No connection");      

       try {
            conn.setAutoCommit(false);
            boolean committed = false;
                try {
                       PreparedStatement passwordQuery = conn.prepareStatement(
                            "SELECT passwd from USERS WHERE userz = ?");
                       passwordQuery.setString(1, userToCheck);

                       ResultSet result = passwordQuery.executeQuery();

                       if(result.next()){
                            storedPassword = result.getString("passwd");
                       }

                       conn.commit();
                       committed = true;
                 } finally {
                       if (!committed) conn.rollback();
                       }
            }
                finally {               
                conn.close();

                }      
       return storedPassword;

       }       

       /** compare the user and the password */
       public String user_compare() throws NoSuchAlgorithmException, SQLException { 
            String hash_passwd;           
            String passwdQuery;

            /** check the password into Oracle using the username */
            passwdQuery = CheckUserDB(user);

            /** convert the plain password in SHA-256 hash */
            hash_passwd = string_hash(password);                                  

            if (password.equals(passwdQuery)){      // just for example, non encrypted passwords are compared
                return "success";        
            } else {
                return "failure";               
            }

       }            

}

Can you recommend me a good web site with tutorials how to write SQL statements with Java Server Faces 2.0

Regards
Peter

Answer 1

You have two questions in one post and I will answer them:

A. regarding the datatable issue:
I would recommend to you to use either of the below open source components:

1. PrimeFaces which has a datatable
2. OpenFaces which also has a datatable.

Inside each of the show case you will see examples how of to display it.

I would recommend first to read the getting started guide of each.

If you want to compare them this answer can help you.

B. SQL statement has not got to do with JSF. JSF is a web framework, MVC. SQL statements -will be used as in the same way that you would choose in pure java. If you are looking for a framework, the most common one for database approach in Java is Hibernate. It may take you a while to learn it, and there are many tutorials on the internet but it will ease your coding life.

See Hibernate getting started

EDITED

BalusC had pointed out to me that I should recommend also the simple <h:datatable>. See an example here