Problemas com Dao

package br.com.caelum.jdbc.dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import br.com.caelum.jdbc.ConnectionFactory;
import br.com.caelum.jdbc.modelo.Contato;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;

public class ContatoDAO {
	
	private Connection connection;
	public ContatoDAO() throws SQLException{
		this.connection = ConnectionFactory.getConnection();
	
			}
	public void adiciona(Contato contato) throws SQLException{
		
		//PreparedStatement stmt = this.connection.PreparedStatement("insert into contatos (nome,email, endereco) values (?,?,?)");
		PreparedStatement stmt = (PreparedStatement) this.connection .prepareStatement("insert into contatos (nome,email,endereco), values (?,?,?");
		
		
		stmt.setString(1, contato.getNome());
		stmt.setString(2, contato.getEmail());
		stmt.setString(3, contato.getEndereco());
		
		//executa
		stmt.execute();
		stmt.close();
	}
	PreparedStatement stmt = (PreparedStatement) this.connection.prepareStatement("select * from contatos");
	ResultSet rs = stmt.executeQuery();
	
	List<Contato> contatos = new ArrayList<Contato>();

	while (rs.next()){
		//criando o objeto Contato
		Contato contato = new Contato();
		contato.setNome(rs.getString("nome"));
		contato.setEmail(rs.getString("email"));
		contato.setEndereco(rs.getString("endereco"));
		
		//adiciona objeto a lista
		contatos.add(contato);
	}
	
rs.close();
stmt.close();
return contatos;


	
}
	
	
}