JDBC: Change column name in a database table Java Example Program

Program:

import java.io.*;
import java.sql.*;

public class ChangeColumnName {
public static void main(String[] args) {
System.out.println("Change column name in a database table example!");
Connection con = null;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection
("jdbc:mysql://localhost:3306/abhi","root","root");
try{
Statement st = con.createStatement();
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter table name:");
String table = bf.readLine();
System.out.println("Enter old column name:");
String old_col = bf.readLine();
System.out.println("Enter new column:");
String new_col = bf.readLine();
System.out.println("Enter data type:");
String type = bf.readLine();
int n = st.executeUpdate
("ALTER TABLE "+table+" CHANGE "+old_col+" "+new_col+" "+type);
System.out.println("Query OK, "+n+" rows affected");
}
catch (SQLException s){
System.out.println("Wrong entry!");
}
}
catch (Exception e){
e.printStackTrace();
}
}
}