How to specify DataSource in JdbcTemplate?

Question

In my application.properties I have set:

datasource.test.driverClass=org.postgresql.Driver
datasource.test.url=jdbc:postgresql://localhost:5433/test
datasource.test.username=admin
datasource.test.password=admin

logging.level.com.eternity = DEBUG

In my controller, I am trying to execute some SQL query form a string like this:

String selectQueryPartOne = "SELECT name, ("+ StringUtils.join(sumString, " + ")+") AS 'Price' FROM house WHERE NOT (" +StringUtils.join(sumString, " IS NULL OR ")+" IS NULL);";
JdbcTemplate statement = new JdbcTemplate();
statement.queryForList(selectQueryPartOne);

Which would work fine, however, I am receiving the following error:

java.lang.IllegalArgumentException: No DataSource specified

I've discovered, that in my statement object, I need to setDataSource first. However, I have no idea where I can get this dataSource object. Could you help?

Answer 1

When you create the JdbcTemplate instance yourself, you are working outside of the Spring dependency injection, and therefore will not have the DataSource injected. You need to use the Spring-provided instance via autowiring, something like:

@Controller
public class MyController {
    @Autowired private JdbcTemplate jdbcTemplate;

    @RequestMapping("/")
    public String myAction(){
        // do stuff with the jdbc template
    }
}

Also, the Spring and Spring-boot documentation are great resources for further study on working with spring.