1. IMPORTANT CODDES(Part I)
To get Integer value from Combobox:-
int a = Integer.parseInt((String)jcombobox1.getSelectedItem());
To get string value from Combobox:-
String abc = (String)jcombobox1.getSelectedItem();
or
String abc = String.valueOf(jcombobox1.getSelectedItem());
To enable or disable textbox according to requirement:-
jTextfield1.setEnable(false);
To Count Vowels and consonant
int vowelcount=0;
char c;
String a ="Kulbhushan";
for( int i = 0; i < a.length(); i++)
{
c = a.charAt(i);
switch(c)
{
case 'a':
System.out.println("Vowel"+c);
vowelcount++;
break;
case 'e':
System.out.println("Vowel"+c);
vowelcount++;
break;
case 'i':
System.out.println("Vowel"+c);
vowelcount++;
break;
case 'o':
System.out.println("Vowel"+c);
vowelcount++;
break;
case 'u':
System.out.println("Vowel"+c);
vowelcount++;
break;
}
}
System.out.println("Total no of Vowels : " + vowelcount);
System.out.println("Total no of Consonant : " + (a.length() - vowelcount));
To Check Login ID and Password
String a = jTextField1.getText();
String p = new String(jPasswordField1.getPassword());
if(a.equals("kulbhushan") && p.equals("sir"))
{
JOptionPane.showMessageDialog(this, "Successful login");
}
else
{
JOptionPane.showMessageDialog(this, "login failed");
}
To change value of combobox at selectedindexchanged:-
Right click on combobox -- Goto Events --- itemstatechange property
--- then write ur own code
2. Important Codes(Part II)
To fill combobox through loop:-
for(int i=1;i<=10;i++)
{
cmb.addItem(i);
}
To print record in netbeans:-
private void BtnPrintActionPerformed(java.awt.event.ActionEvent evt) {
// Here we use Table component to print data
MessageFormat header = new MessageFormat("Patient Information");
MessageFormat Footer = new MessageFormat("Page{0,number,integer}");
try
{
Mytable.print(JTable.PrintMode.NORMAL,header,Footer);
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(null, ex);
}
}
To set selectedindexchanged property of combobox:-
if(jComboBox1.getSelectedIndex()<=0)
{
JOptionPane.showMessageDialog(this, "Select Item first");
}
How to fill string in combbox:-
String[] a = new String[2];
a[0]="January";
a[1]="February";
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(a));
To check whether textbox is empty or not:-
String a = jTextField1.getText();
if(a.isEmpty()==true)
{
JOptionPane.showMessageDialog(this, "Please fill value");
}
To Delete Record on button click as shown below:-
Right Click on button and make this event
int MySlectedRow = jTable1.getSelectedRow();
if(MySlectedRow==-1)
{
JOptionPane.showMessageDialog(this, "Please Select At least one Row");
}
else
{
int response = JOptionPane.showConfirmDialog(null, "Do you want to continue","Confirm",JOptionPane.YES_NO_CANCEL_OPTION,JOptionPane.QUESTION_MESSAGE);
if(response==JOptionPane.YES_OPTION)
{
int row = jTable1.getSelectedRow();
int row = jTable1.getSelectedRow();
// 0 means first column
// 1 means second column
// 2 means third column
int ID = Integer.parseInt(jTable1.getValueAt(row, 0).toString());
jTextField2.setText(jTable1.getValueAt(row, 1).toString());
// Now write your delete code here and pass the id to delete the object
}
}
3. Important Codes(Part III)
To enters only numbers in textbox:-
import java.awt.event.KeyEvent;
private void jTextField1KeyPressed(java.awt.event.KeyEvent evt) {
char c = evt.getKeyChar();
if ( ((c < '0') || (c > '9')) && (c != KeyEvent.VK_BACK_SPACE))
{
jTextField1.setEditable(false);
}
else
{
jTextField1.setEditable(true);
}
}
Print Record Using Professional way
Step 1:- Add these library
import javax.swing.JFrame;
import java.awt.print.PrinterException;
import java.util.logging.Level;
import java.util.logging.Logger;
Step 2:
private void btnAddRecordActionPerformed(java.awt.event.ActionEvent evt) {
txtReceipt.append("\t\t\t Jayshree Periwal International School" + "\n\n"+
"\n ##############################\n"+"\n\n"+
"First Name \t\t\t" + txtfirstname.getText()+ "\n\n"+
"Last Name:\t\t\t" + txtlastname.getText()+ "\n\n"+
"Mobile Number:\t\t\t" + txtmobileno.getText()+ "\n\n"+
"Refrence Number:\t\t" + txtrefreence.getText()+ "\n\n"
);
}
Step 3 :
private void BtnPrintActionPerformed(java.awt.event.ActionEvent evt) {
try {
txtReceipt.print();
} catch (PrinterException ex) {
Logger.getLogger(Temp.class.getName()).log(Level.SEVERE, null, ex);
}
}
Validation of remove duplicate entry:-
import java.sql.SQLException;
try
{
Statement stmk =(Statement)con.createStatement();
String sqlk ;
sqlk = "insert into take(mobileno,username)values('"+ username +"','"+ ddk +"')";
stmk.executeUpdate(sqlk);
}
catch(SQLException e)
{
System.out.println("Message = " + e.getMessage());
JOptionPane.showMessageDialog(this, e.getMessage());
}
To show tables and schema in MYSQL:-
1. show tables;
2. desc student; or Describe student;
To create code on menu item:-
private void AddPatinetActionPerformed(java.awt.event.ActionEvent evt) {
this.setVisible(false);
new Dashboard().setVisible(true);
}
To set maxlength of textbox:-
You have to create this code at keypressed event
private void jTextField1KeyPressed(java.awt.event.KeyEvent evt) {
if(jTextField1.getText().length()>=5)
{
jTextField1.setText(jTextField1.getText().substring(0, 4));
}
To set Return Type function in netbeans:-
Step 1 :- First create class in the project
Step 2 :- Than make a function like this
Step 3:- Now call the function on button click like this
private void btnCalculateReturnActionPerformed(java.awt.event.ActionEvent evt) {
NewClass ClassObject = new NewClass();
int kuldd = ClassObject.SumTwoNumbers(5, 10);
JOptionPane.showMessageDialog(this, kuldd);
}
4. Important Codes(Part IV)
To set current system date and time in netbeans:-
You have to add this files in header first
import java.util.Date;
import java.text.SimpleDateFormat;
import java.util.Calendar;
private void formWindowOpened(java.awt.event.WindowEvent evt) {
// TODO add your handling code here:
SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");
Date date = new Date();
jLabel2.setText(formatter.format(date));
Calendar cal = Calendar.getInstance();
cal.getTime();
SimpleDateFormat sdfd24hour = new SimpleDateFormat("HH:mm:ss");
SimpleDateFormat sdfd12hour = new SimpleDateFormat("hh:mm a");
jLabel3.setText(sdfd12hour.format(cal.getTime()));
jLabel4.setText(sdfd24hour.format(cal.getTime()));
}
To set break point in netbeans:-
Step1: first of all pehle ki tarah breakpoint lagao ASP.net ki tarah
Step 2: then keyboar Ctrl+Shift+f5 dabao, page run ho jaiyega
Step 3: phir button pe click kare jaha aapne brk point lagaya tha
Step 3:- thne f8 dabate jao or value check hoti jaigi
(In case if it is not working with f8 then use f7)
(Note For checking loop USe F8)
Refresh Code:-
String studid = txtstudname.getText();
String studname = txtfathername.getText();
try
{
Class.forName("java.sql.DriverManager");
Connection conk = (Connection)DriverManager.getConnection("jdbc:mysql://localhost:3306/school","root","kulbhushan");
Statement stmk =(Statement)conk.createStatement();
DefaultTableModel model = (DefaultTableModel)jTable1.getModel();
String myquery;
myquery = "select * from studinfo";
ResultSet rs = stmk.executeQuery(myquery);
int rows = model.getRowCount();
for(int i = rows - 1; i >=0; i--)
{
model.removeRow(i);
}
while(rs.next())
{
String teachername = rs.getString("mobileno");
String contactno = rs.getString("username");
model.addRow(new Object[]{teachername,contactno});
}
stmk.close();
conk.close();
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(this, ex.getMessage());
}
Delete Code in netbeans:-
int response;
if(txtteachername.getText().isEmpty())
{
JOptionPane.showMessageDialog(this, "Please Select Record First!!");
}
else
{
try
{
Class.forName("java.sql.DriverManager");
Connection conk = (Connection)DriverManager.getConnection("jdbc:mysql://localhost:3306/school","root","kullu");
Statement stmk =(Statement)conk.createStatement();
response = JOptionPane.showConfirmDialog(null, "Do you want to continue","Confirm",JOptionPane.YES_NO_CANCEL_OPTION,JOptionPane.QUESTION_MESSAGE);
if(response==JOptionPane.YES_OPTION)
//JOptionPane.showMessageDialog(this, "yes right");
{
String DeleteQuery;
DeleteQuery = "delete from staff where teacherid=" + Mainteacherid + "";
stmk.executeUpdate(DeleteQuery);
JOptionPane.showMessageDialog(this, "Deleted Successfully");
txtteachername.setText("");
txtcontactno.setText("");
txtsalary.setText("");
DefaultTableModel model = (DefaultTableModel)jTable1.getModel();
String myquery;
myquery = "select * from staff";
ResultSet rs = stmk.executeQuery(myquery);
while(rs.next())
{
String teacherid = rs.getString("teacherid");
String teachername = rs.getString("teachername");
String contactno = rs.getString("contactno");
String teachingclass = rs.getString("teachingclass");
String salary = rs.getString("salary");
String Qualification = rs.getString("qualification");
String Experience = rs.getString("experience");
String gender = rs.getString("gender");
model.addRow(new Object[]{teacherid,teachername,gender,contactno,teachingclass,salary,Qualification,Experience});
}
}
stmk.close();
conk.close();
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(this, ex.getMessage());
}
}
Use of Tree Component in netbeans:-
If u want to use tree component than use it Event- Tree_selection and write
your code according ur requirement.
5. Important Codes(Part IV)
Database connectivity in netbeans:-
import javax.swing.JOptionPane;
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.sql.Driver;
import javax.swing.table.DefaultTableModel;
private void btnsaveActionPerformed(java.awt.event.ActionEvent evt) {
String teachername = txtteachername.getText();
String contactno = txtcontactno.getText();
String salary = txtsalary.getText();
String teachingclass = (String)cmbteachingclass.getSelectedItem();
String Qualification = (String)cmbqualification.getSelectedItem();
String Experience = (String)cmbexperience.getSelectedItem();
if(teachername.isEmpty())
{
JOptionPane.showMessageDialog(this, "Please Teacher Name First");
}
else if(contactno.isEmpty())
{
JOptionPane.showMessageDialog(this, "Please fill Contact No");
}
else if(salary.isEmpty())
{
JOptionPane.showMessageDialog(this, "Please fill Salary");
}
else
{
String Mygender="";
if(rdmale.isSelected())
{
Mygender=rdmale.getText();
}
else
{
Mygender=rdfemale.getText();
}
try
{
Class.forName("java.sql.DriverManager");
Connection conk = (Connection)DriverManager.getConnection("jdbc:mysql://localhost:3306/school","root",
"password");
Statement stmk =(Statement)conk.createStatement();
String sqlk ;
sqlk = "insert into staff(teachername,gender,contactno,teachingclass,salary,qualification,experience)
values('"+ teachername +"','"+ Mygender + "','" + contactno + "',
'" + teachingclass +"','"+ salary +"','" + Qualification +"','"+ Experience+"')";
stmk.executeUpdate(sqlk);
JOptionPane.showMessageDialog(this, "Saved Successfully");
txtteachername.setText("");
txtcontactno.setText("");
DefaultTableModel model = (DefaultTableModel)jTable1.getModel();
String myquery;
myquery = "select * from staff";
ResultSet rs = stmk.executeQuery(myquery);
while(rs.next())
{
int Teacherid;
Teacherid = Integer.parseInt(rs.getString("teacherid"));
teachername = rs.getString("teachername");
contactno = rs.getString("contactno");
Mygender= rs.getString("gender");
teachingclass = rs.getString("teachingclass");
salary = rs.getString("salary");
Qualification = rs.getString("Qualification");
Experience = rs.getString("Experience");
//model.fireTableDataChanged();
model.addRow(new Object[]{Teacherid,teachername,Mygender,contactno,teachingclass,salary,
Qualification,Experience});
}
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(this, ex.getMessage());
}
}
6. Important Codes(Part VI)
Database Connectivity in netbeans(Xampp):-
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.swing.JOptionPane;
import java.sql.*;
import java.util.*;
String username = txtusername.getText();
String password = txtpassword.getText();
try
{
String url="jdbc:mysql://localhost:3306/school";
Properties prop=new Properties();
prop.setProperty("user","root");
prop.setProperty("password","");
Driver d = new com.mysql.jdbc.Driver();
Connection con = d.connect(url,prop);
if(con==null)
{
System.out.println("connection failed");
return;
}
else
{
Statement stmk =(Statement)con.createStatement();
String myquery;
myquery = "select * from stud";
ResultSet rs = stmk.executeQuery(myquery);
while(rs.next())
{
String MYusername = rs.getString("studname");
String MYPassword = rs.getString("fname");
if(username.equals(MYusername) && password.equals(MYPassword))
{
this.setVisible(false);
new staff().setVisible(true);
}
else
{
JOptionPane.showMessageDialog(this, "Incorrect Username Or Password");
}
}
}
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(this, ex.getMessage());
}
7. Important Codes(Part VII)
When Xampp Gives Problem after Installation:-
HOW TO START:-
Open the browser and just type localhost:80
or
localhost:80/phpmyadmin
NOTE:- Some times we see that after installing it not work it gives the error
404 NOt Found. Than we have to change some settings.
Step 1 :- U see that if folders save on C: Drive under the name
Xampp. after that go to the folder apache, than go to
the folder conf than go the file httpd.conf.
Step 2:- Just open the httpd.conf file with notepad and search
with the keyword Listen u will notice that there
is a wriiten a port no 80 in front of listen,
now just replace 80 to 81 or whatever u want to give the
port no.
Step 3:- Now open the browser and type:- localhost:81
OR
localhost:81/phpmyadmin
