Best connection?

[oaklander]

What is the best way to connect to a database in Java Class?
I have used 3 different ways and would like to know what is the most efficient one.

1- Put the connection as a data member:

public class DatabaseHelperClass
{ 
    private Connection connection = new DbConnectionManager().getConnection();
 
    public void insertDb(DbBean db) throws SQLException  {
    PreparedStatement stmt = connection.prepareStatement("insert ..");
    ...
    }
 
   public void updateDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

2 - Put connection in Constructor:

public class DatabaseHelperClass
{ 
    public DatabaseHelperClass() {
    Connection connection = new DbConnectionManager().getConnection();
    }
 
     public void insertDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("insert ..");
     ...
    }
 
    public void updateDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

3- Put connection in every method that needs a connection:

public class DatabaseHelperClass
{ 
     public void insertDb(DbBean db) throws SQLException  {
     Connection connection = new DbConnectionManager().getConnection();
     PreparedStatement stmt = connection.prepareStatement("insert ..");
     ...
    }
 
 public void updateDb(DbBean db) throws SQLException  {
     Connection connection = new DbConnectionManager().getConnection();
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

[r035198x]

What is the best way to connect to a database in Java Class?
I have used 3 different ways and would like to know what is the most efficient one.

1- Put the connection as a data member:

public class DatabaseHelperClass
{ 
    private Connection connection = new DbConnectionManager().getConnection();
 
    public void insertDb(DbBean db) throws SQLException  {
    PreparedStatement stmt = connection.prepareStatement("insert ..");
    ...
    }
 
   public void updateDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

2 - Put connection in Constructor:

public class DatabaseHelperClass
{ 
    public DatabaseHelperClass() {
    Connection connection = new DbConnectionManager().getConnection();
    }
 
     public void insertDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("insert ..");
     ...
    }
 
    public void updateDb(DbBean db) throws SQLException  {
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

3- Put connection in every method that needs a connection:

public class DatabaseHelperClass
{ 
     public void insertDb(DbBean db) throws SQLException  {
     Connection connection = new DbConnectionManager().getConnection();
     PreparedStatement stmt = connection.prepareStatement("insert ..");
     ...
    }
 
 public void updateDb(DbBean db) throws SQLException  {
     Connection connection = new DbConnectionManager().getConnection();
     PreparedStatement stmt = connection.prepareStatement("update ..");
     ...
    }

2.) Won't compile
3.) Wastes resources by creating a connection everytime even when one is already available. Google connection pooling for more details.