Statement stmt = null;
try {
  stmt = conn.createStatement( );
  . . .
}
catch (SQLException e) {
  . . .
}
finally {
  . . .
}

Statement stmt = null;
try {
  stmt = conn.createStatement( );
  . . .
}
catch (SQLException e) {
  . . .
}
finally {
  stmt.close();
}

PreparedStatement pstmt = null;
try {
  String SQL = "Update Employees SET age = ? WHERE id = ?";
  pstmt = conn.prepareStatement(SQL);
  . . .
}
catch (SQLException e) {
  . . .
}
finally {
  . . .
}

PreparedStatement pstmt = null;
try {
  String SQL = "Update Employees SET age = ? WHERE id = ?";
  pstmt = conn.prepareStatement(SQL);
  . . .
}
catch (SQLException e) {
  . . .
}
finally {
  pstmt.close();
}

//STEP 1. Import required packages
import java.sql.*;

public class JDBCExample {
  // JDBC driver name and database URL
  static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; 
  static final String DB_URL = "jdbc:mysql://localhost/EMP";

  // Database credentials
  static final String USER = "username";
  static final String PASS = "password";
  
  public static void main(String[] args) {
  Connection conn = null;
  PreparedStatement stmt = null;
  try{
   //STEP 2: Register JDBC driver
   Class.forName("com.mysql.jdbc.Driver");

   //STEP 3: Open a connection
   System.out.println("Connecting to database...");
   conn = DriverManager.getConnection(DB_URL,USER,PASS);

   //STEP 4: Execute a query
   System.out.println("Creating statement...");
   String sql = "UPDATE Employees set age=? WHERE id=?";
   stmt = conn.prepareStatement(sql);
   
   //Bind values into the parameters.
   stmt.setInt(1, 35); // This would set age
   stmt.setInt(2, 102); // This would set ID
   
   // Let us update age of the record with ID = 102;
   int rows = stmt.executeUpdate();
   System.out.println("Rows impacted : " + rows );

   // Let us select all the records and display them.
   sql = "SELECT id, first, last, age FROM Employees";
   ResultSet rs = stmt.executeQuery(sql);

   //STEP 5: Extract data from result set
   while(rs.next()){
     //Retrieve by column name
     int id = rs.getInt("id");
     int age = rs.getInt("age");
     String first = rs.getString("first");
     String last = rs.getString("last");

     //Display values
     System.out.print("ID: " + id);
     System.out.print(", Age: " + age);
     System.out.print(", First: " + first);
     System.out.println(", Last: " + last);
   }
   //STEP 6: Clean-up environment
   rs.close();
   stmt.close();
   conn.close();
  }catch(SQLException se){
   //Handle errors for JDBC
   se.printStackTrace();
  }catch(Exception e){
   //Handle errors for Class.forName
   e.printStackTrace();
  }finally{
   //finally block used to close resources
   try{
     if(stmt!=null)
      stmt.close();
   }catch(SQLException se2){
   }// nothing we can do
   try{
     if(conn!=null)
      conn.close();
   }catch(SQLException se){
     se.printStackTrace();
   }//end finally try
  }//end try
  System.out.println("Goodbye!");
}//end main
}//end JDBCExample

C:>javac JDBCExample.java

C:>java JDBCExample

Connecting to database...
Creating statement...
Rows impacted : 1
ID: 100, Age: 18, First: Zara, Last: Ali
ID: 101, Age: 25, First: Mahnaz, Last: Fatma
ID: 102, Age: 35, First: Zaid, Last: Khan
ID: 103, Age: 30, First: Sumit, Last: Mittal
Goodbye!