Java Help!

annunaki · Sep 25, 2015

normal java login ekak haduwa db text field eke enter karana user pass combination eka db ekath ekka match wenawanam log wena widiyata bt mona value enter karala login button eka click karama java.lang.nullpointerexception error eka enawa :\

Code:

 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try {
            
            String sql = "SELECT * FROM logins WHERE user=? AND pwd=?";
            pst = conn.prepareStatement(sql);
            pst.setString(1,user.getText());
            pst.setString(2,String.valueOf(pass.getPassword()));
            rs = pst.executeQuery();
            
            if(rs.next()){
                
                JOptionPane.showMessageDialog(null,"Welcome "+user.getText());
                
                main m1 = new main();
                m1.setVisible(true);
                this.dispose();
                
            }
            else{
                JOptionPane.showMessageDialog(null,"Invalid Username and Password");
            }
            
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null,e);
        }
        
    }

Chathuranga1 · Sep 25, 2015

ai ban uba oya button eka athulema sql connection eka hadanne.. MVC gahapanko ..lesiyi ubata ..!!

bump thama ban .!

Chathuranga1 · Sep 25, 2015

uba mekada oya gahuwe

login

annunaki · Sep 25, 2015

Chathuranga1 said:
ai ban uba oya button eka athulema sql connection eka hadanne.. MVC gahapanko ..lesiyi ubata ..!!

bump thama ban .!

form windows eka open weddima db ekata connect wenna dala thiyenne button eka click karama query eka run wenna dala thiyenne

Chathuranga1 · Sep 25, 2015

annunaki said:
form windows eka open weddima db ekata connect wenna dala thiyenne button eka click karama query eka run wenna dala thiyenne

මචන් මේක පොඩ්ඩක් ට්‍රයි කරලා බලහන් ..මම ගහපු එකක් ඕක

Code:

 public void login() {
        try {
            ResultSet rset = db.getdata("SELECT * FROM login");
            while (rset.next()) {
                String username = rset.getString("name");
                String password = rset.getString("password");

                if ((username.equals(txt_username.getText()) && password.equals(String.valueOf(txt_pass.getPassword())))) {

                  
                    new Home().setVisible(true);
                    
                    this.dispose();
                   
                } else {
                    JOptionPane.showMessageDialog(this, " ", "Login Eroor", WIDTH, null);
                                 
                }

            }

        } catch (Exception e) {
            System.out.println(e);
        }

    }

මේක තමයි DB class එක ..මේක උබ ගහන ඕනේ ෆෝරම් එකකට ඉම්පෝර්ට් කරපන් ..

Code:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package config;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 *
 * @author Rish
 */
public class DB {


    static Connection con() throws Exception{

        Class.forName("com.mysql.jdbc.Driver");
        Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test-app?useUnicode=true&characterEncoding=UTF-8","root","");
        
       
      // Statement st=con.createStatement();
        return con;

    }
    public ResultSet getdata(String sql) throws Exception{

        Statement st=con().createStatement();
        ResultSet rset = st.executeQuery(sql);
        return rset;
    }
   public void putdata(String sql) throws Exception{

        Statement st=con().createStatement();
        st.executeUpdate(sql);
    }
}

u_make_me_sick_ · Sep 25, 2015

annunaki said:

normal java login ekak haduwa db text field eke enter karana user pass combination eka db ekath ekka match wenawanam log wena widiyata bt mona value enter karala login button eka click karama java.lang.nullpointerexception error eka enawa :\

Code:

 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try {
            
            String sql = "SELECT * FROM logins WHERE user=? AND pwd=?";
            pst = conn.prepareStatement(sql);
            pst.setString(1,user.getText());
            pst.setString(2,String.valueOf(pass.getPassword()));
            rs = pst.executeQuery();
            
            if(rs.next()){
                
                JOptionPane.showMessageDialog(null,"Welcome "+user.getText());
                
                main m1 = new main();
                m1.setVisible(true);
                this.dispose();
                
            }
            else{
                JOptionPane.showMessageDialog(null,"Invalid Username and Password");
            }
            
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null,e);
        }
        
    }

Error stack trace eka danna, anika main m1= new main() kiyana eka harida?
Kohoma unath bad coding

u_make_me_sick_ · Sep 25, 2015

Chathuranga1 said:

මචන් මේක පොඩ්ඩක් ට්‍රයි කරලා බලහන් ..මම ගහපු එකක් ඕක

Code:

 public void login() {
        try {
            ResultSet rset = db.getdata("SELECT * FROM login");
            while (rset.next()) {
                String username = rset.getString("name");
                String password = rset.getString("password");

                if ((username.equals(txt_username.getText()) && password.equals(String.valueOf(txt_pass.getPassword())))) {

                  
                    new Home().setVisible(true);
                    
                    this.dispose();
                   
                } else {
                    JOptionPane.showMessageDialog(this, " ", "Login Eroor", WIDTH, null);
                                 
                }

            }

        } catch (Exception e) {
            System.out.println(e);
        }

    }

Mekath ekka baladdi aruge code eka honday. Mokada bola okkoma users lawa load karanne?DB calls view eke karanna epa. Business logics wenama manager class ekaka thiya ganna? DB calls walata wenama class ekak thiyaganna.

Chathuranga1 · Sep 25, 2015

u_make_me_sick_ said:
Mekath ekka baladdi aruge code eka honday. Mokada bola okkoma users lawa load karanne?DB calls view eke karanna epa. Business logics wenama manager class ekaka thiya ganna? DB calls walata wenama class ekak thiyaganna.

මේක බන් මම නිකන් ගහපු එකක් ..අරුට හොයා තේරුම් ගන්න ලේසි වෙන්නයි දැම්මේ ..
මේකේ ලොගින් users ලා කඩල නෑ බන් ..එක ඇඩ්මින් කෙනයි ඉන්නේ
සාමන්යෙන් මම ලෝගික් වලටනම් වෙනම class එකක් හදනවා ..db call කරද්දී නම් බන් db class එකේ function call කරන එක තමා කරන්නේ

niyomax · Sep 25, 2015

DB Class එක වෙනම class එකක ලියලා ඒක login ෆෝම් එක සහිත එකේ login button එකේදි කෝල් කලොත් හරි නේද? :yes:

niyomax · Sep 25, 2015

Chathuranga1 said:
මේක බන් මම නිකන් ගහපු එකක් ..අරුට හොයා තේරුම් ගන්න ලේසි වෙන්නයි දැම්මේ ..
මේකේ ලොගින් users ලා කඩල නෑ බන් ..එක ඇඩ්මින් කෙනයි ඉන්නේ
සාමන්යෙන් මම ලෝගික් වලටනම් වෙනම class එකක් හදනවා ..db call කරද්දී නම් බන් db class එකේ function call කරන එක තමා කරන්නේ

login walata wenama class ekak keewe? login form ekak wenama class ekaka heduwann hari neda machan ? (maath java igenaganna gaman ekai)

Chathuranga1 · Sep 25, 2015

niyomax said:
login walata wenama class ekak keewe? login form ekak wenama class ekaka heduwann hari neda machan ? (maath java igenaganna gaman ekai)

අර මචන් මමං මම ගහල තියෙන්නේ ඒ විදිහට :yes:

niyomax · Sep 25, 2015

meka kohomada balanna kauruhari (weda karanawa) mam keewe standard eka

DB Class

Code:

package elakiri;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBClass {
    private static final String USERNAME= "root";
    private static final String PASSWORD= "";
    private static final String CONN_STRING= "jdbc:mysql://localhost:3306/exampleelakiri";
    
    public static Connection ConnectDB() throws SQLException{
        
        Connection conn=null;
        
        try{
            conn=DriverManager.getConnection(CONN_STRING,USERNAME,PASSWORD);
            return conn;
        }catch(SQLException e){
            System.err.println(e);
     
        }
            return null;
    }

   
}

login class ekema

Code:

public class LoginForm extends javax.swing.JFrame {
Connection conn=null;
ResultSet rs=null;
PreparedStatement pst=null;

    public LoginForm() throws SQLException {
        initComponents();
        conn= DBClass.ConnectDB();
    }

Button
Action Perfomed ekata

Code:

   private void cmd_loginActionPerformed(java.awt.event.ActionEvent evt) {                                          
        String sql = "SELECT * from adminstbl where username=? and password=?";
        try{
            pst=conn.prepareStatement(sql);
            pst.setString(1, uname.getText());
            pst.setString(2, pword.getText());
            
            rs=pst.executeQuery();
            if(rs.next()){
                JOptionPane.showMessageDialog(null, "Username and Password is correct");
                rs.close();
                pst.close();
                close();
                
                Options s=new Options();
                s.setVisible(true);
               
            }
            else{
                JOptionPane.showMessageDialog(null, "Username and Password is incorrect");
            }
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, e);
         
        }
       
    }

Chathuranga1 · Sep 25, 2015

niyomax said:

meka kohomada balanna kauruhari (weda karanawa) mam keewe standard eka

DB Class

Code:

package elakiri;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBClass {
    private static final String USERNAME= "root";
    private static final String PASSWORD= "";
    private static final String CONN_STRING= "jdbc:mysql://localhost:3306/exampleelakiri";
    
    public static Connection ConnectDB() throws SQLException{
        
        Connection conn=null;
        
        try{
            conn=DriverManager.getConnection(CONN_STRING,USERNAME,PASSWORD);
            return conn;
        }catch(SQLException e){
            System.err.println(e);
     
        }
            return null;
    }

   
}

login class ekema

Code:

public class LoginForm extends javax.swing.JFrame {
Connection conn=null;
ResultSet rs=null;
PreparedStatement pst=null;

    public LoginForm() throws SQLException {
        initComponents();
        conn= DBClass.ConnectDB();
    }

Button
Action Perfomed ekata

Code:

   private void cmd_loginActionPerformed(java.awt.event.ActionEvent evt) {                                          
        String sql = "SELECT * from adminstbl where username=? and password=?";
        try{
            pst=conn.prepareStatement(sql);
            pst.setString(1, uname.getText());
            pst.setString(2, pword.getText());
            
            rs=pst.executeQuery();
            if(rs.next()){
                JOptionPane.showMessageDialog(null, "Username and Password is correct");
                rs.close();
                pst.close();
                close();
                
                Options s=new Options();
                s.setVisible(true);
               
            }
            else{
                JOptionPane.showMessageDialog(null, "Username and Password is incorrect");
            }
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, e);
         
        }
       
    }

එල
මේකත් පොඩ්ඩක් බලන්න තව ඕනේ නම්
MVC

KingCM · Sep 25, 2015

niyomax said:
meka kohomada balanna kauruhari (weda karanawa) mam keewe standard eka

Standard eka hari.... :yes:

------------------------------------

KingCM · Sep 25, 2015

programming club thread eke mama post ekak dala athi ....

password hash karanne kohomada salt karanne kohomada kiyala....

poddak kiyawala balanna..... :nerd:

thread post eke link eka mage laga thiyenwa ..... eth poddak ubalama poddak hoyala balapallako..... :rofl:

after 100 page balanna....

niyomax · Sep 25, 2015

KingCM said:
programming club thread eke mama post ekak dala athi ....

password hash karanne kohomada salt karanne kohomada kiyala....

poddak kiyawala balanna.....

thanx macho mama balannam

niyomax · Sep 25, 2015

than q machanla

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