This Java code implements a basic text search feature by: 1) Creating a JComboBox and JTextField to allow the user to enter search text and see results. 2) Adding a key listener to the text field to detect key presses and retrieve search results from an Oracle database on key release. 3) Constructing a SQL query with a LIKE clause to find database records where a field matches the entered text, and adding any results to the dropdown.

1. TextSearch. Java codes
package com.nt.search;
import java.awt.GridLayout;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class TextSearch extends JFrame implements KeyListener
{
JComboBox jb=new JComboBox();
JTextField tx=new JTextField();
JPanel p=new JPanel();
JPanel p1=new JPanel();
String str1 = "";
char s = ' ';
String wildCard = "";
public TextSearch() {
add(p);
add(p1);
setLayout(null);
p.setLayout(new GridLayout(1,1, 1, 1));
p.setBounds(20, 80, 200, 40);
p.add(jb);
p1.setLayout(new GridLayout(1,1, 1, 1));
p1.setBounds(20, 20, 200, 40);
p1.add(tx);
tx.addKeyListener(this);
setSize(300, 400);
setLocation(600, 40);
setVisible(true);
setResizable(false);
setTitle("Key Listener Test");
}
@Override
public void keyPressed(KeyEvent e)
{
}

2. @Override
public void keyReleased(KeyEvent e)
{
jb.removeAllItems();
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection
con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","scott","t
iger");
wildCard = tx.getText();
String qry="select ename from emp where ename like
'"+wildCard+"%'";
System.out.println(qry);
Statement st=con.createStatement();
ResultSet rs=st.executeQuery(qry);
while(rs.next())
{
jb.addItem(rs.getString(1));
}
}catch(Exception a){
a.printStackTrace();
}finally{
if(e.getKeyChar() == KeyEvent.VK_BACK_SPACE &&
tx.getText().equals("")){
jb.removeAllItems();
}
}
}
@Override
public void keyTyped(KeyEvent e)
{
/*try
{
StringBuilder sb=new StringBuilder("");
if(tx.getText().equals(""))
str1 = "";
else
str1 = tx.getText();
jb.removeAllItems();
if(e.getKeyChar() != KeyEvent.VK_BACK_SPACE){
s=e.getKeyChar();
}else{
str1 = tx.getText();

3. }
sb = new StringBuilder(str1);
sb.append(s);
String str=sb.toString();
String s1=str+"%";
String s2="'"+s1+"'";
System.out.println(s2);
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection
con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","scott","t
iger");
String qry="select ename from emp where ename like
'"+tx.getText()+"%'";
System.out.println(qry);
Statement st=con.createStatement();
ResultSet rs=st.executeQuery(qry);
while(rs.next())
{
jb.addItem(rs.getString(1));
}
str1=str;
}catch(Exception a){
a.printStackTrace();
}*/
}
public static void main(String[] args)
{
TextSearch is=new TextSearch();
is.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}