Question

I have a DAO with many methods, each containing an SQL statement to execute. I don’t want to hard code SQL strings into the DAO Java class so what’s the best way of managing this scenario? I am thinking of injecting them, but how best to do this?

Cheers,
Matt

Answer 1

You can inject your SQL statements during application initialization.

class MyDAO {
   private String someQuery;

   public void setSomeQuery(String someQuery) {
       this.someQuery = someQuery;
   }

}

Then you can have your SQL statments in XML file, not hardcoded.

<bean class="some.package.MyDAO">
    <property name="someQuery">
        <value>
            SELECT * FROM user WHERE id = ?
        </value>
    </property>
</bean>

You can even externalize your SQL statements to .properties files.

Take a look: http://www.summa-tech.com/blog/2009/04/20/6-tips-for-managing-property-files-with-spring/