Dúvida de fechamento de conexões e utilização do PreparedStatement!

Conexao con = new Conexao();

PreparedStatement psSQL = con.conConect.prepareStatement("SELECT 
A1_COD FROM A1 WHERE A1_COD = '"+ strCodCli +"'");

	ResultSet Resultados = psSQL.executeQuery();
	if (Resultados.next())
{
 strCodPes = Resultados.getString(1);
}
											  	  
if(strCodPes != null)
{
JOptionPane.showMessageDialog(null,"Código já cadastrado!");
											  		
jtfCodCli.setText("");
											  		
jtfCodCli.grabFocus();
											  		
jtfCodCli.setText(""); jtfNomCli.setText("");
												  	
jtfFanCli.setText(""); jtfFisJur.setText("");
												  	
jtfTipCli.setText(""); jtfEndCli.setText("");
												  	
jtfMunCli.setText(""); jtfEstCli.setText("");
												  	
jtfBaiCli.setText(""); jtfCEPCli.setText("");
												  	
jtfTelCli.setText(""); jtfCPFCli.setText("");
												  	
jtfInsCli.setText(""); jtfRGCli.setText("");
												  	
jtfConCli.setText(""); jtfFunCli.setText(""); 
												  	
jtfEmaCli.setText("");
											  		
panCadCli.setVisible(true);
}
else
{
psSQL = con.conConect.prepareStatement("INSERT INTO A1 
VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
											  		
psSQL.setString(1,strCodCli);  psSQL.setString(2,strNomCli);
											  		
psSQL.setString(3,strFanCli);  psSQL.setString(4,strFisJur);
											  		
psSQL.setString(5,strTipCli);  psSQL.setString(6,strEndCli);
											  		
psSQL.setString(7,strMunCli);  psSQL.setString(8,strEstCli);
											  		
psSQL.setString(9,strBaiCli);  psSQL.setString(10,strCEPCli);
											  		
psSQL.setString(11,strTelCli); psSQL.setString(12,strCPFCli);
											  		
psSQL.setString(13,strInsCli); psSQL.setString(14,strRGCli);
											  		
psSQL.setString(15,strConCli); psSQL.setString(16,strFunCli);
											  		
psSQL.setString(17,strEmaCli); psSQL.executeUpdate();
											  		
Resultados.close();
											  		
psSQL.close();
											  		
JOptionPane.showMessageDialog(null,"CADASTRO EFETUADO COM 
SUCESSO!");
											  		
trePriArv.setSelectionRow(1);
													
panCadCli.setVisible(false);
											  	
}