Question

I am trying to connect to a mysql database on my first Spring Project and I seem to be overlooking something really simple.

I have this bean in my application-context.xml file which is commented out!

<bean id="dataSource"
      class="org.springframework.jdbc.datasource.DriverManagerDataSource"
      p:driverClassName="${jdbc.driverClassName}"
      p:url="${jdbc.url}"
      p:username="${jdbc.username}"
      p:password="${jdbc.password}" />

I know this is going to sound stupid, but in order to create a class that connects to a Mysql database using JDBC and the or the Spring JDBCTemplate, what do I do from here?

I am confused about how to populate properties in the bean above, do I do it in a superclass like this and then extend my subclasses from it.

import org.springframework.jdbc.datasource.DriverManagerDataSource;

public class JdbcDao {
     protected DriverManagerDataSource dataSource = new DriverManagerDataSource();
     JdbcDao(){
         dataSource.setDriverClassName("com.mysql.jdbc.Driver");
         dataSource.setUrl("jdbc:mysql://localhost/db_name");
         dataSource.setUsername("bcash");
         dataSource.setPassword("");        
     }    
}

I am confused so any help is truly apprecated,

Many Thanks

Answer 1

See JdbcTemplate Best Practices for further info.

Nutshell: no, your DAO wouldn’t create a new datasource via new; that defeats the purpose of using Spring. Implementations should be injected, not instantiated directly; roughly:

public class TheDaoImpl implements TheDao {

    private JdbcTemplate jdbcTemplate;

    public void setDataSource(DataSource dataSource) {
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }

    // JDBC-backed implementations of TheDao follow...
}

Then in your Spring config (if not using annotations), also roughly:

<bean id="theDao" class="com.bar.plugh.TheDaoImpl" p:dataSource-ref="dataSource" />

(This uses a setter; you could also use an annotation and skip the XML config.)

You could also use JdbcTemplate as your base class and save more energy.

I recommend going over the Data access with JDBC reference docs (if you’re using JDBC), or the corresponding section that deals directly with your ORM choice.