Spring Boot not reading from property file
<p>I have tried every option on web but not able to set the values in following method:</p>

<pre><code>@Configuration
@PropertySource("classpath:application.properties")
public class MyDataSource {
    @Value("${db.driver}") 
    private String DB_DRIVER;

    @Value("${db.url}")
    private String DB_URL;

    @Value("${db.username}")
    private String DB_USERNAME;

    @Value("${db.password}")
    private String DB_PASSWORD;


    @Bean
    public static PropertySourcesPlaceholderConfigurer placeHolderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    public DataSource getDataSource() {
         DriverManagerDataSource dataSource = new DriverManagerDataSource();
         dataSource.setDriverClassName(DB_DRIVER);
         dataSource.setUrl(DB_URL);
         dataSource.setUsername(DB_USERNAME);
         dataSource.setPassword(DB_PASSWORD);

         return dataSource;
     }
}
</code></pre>

<p>My <code>application.properties</code> is in <code>main/resources</code> folder and values can be seen in variables in debug mode. But on running app, it shows <code>Property ' ' must not be empty.</code></p>

<p>EDIT:  I am not sure what can be the issue in first case?
So changed the application.property file as suggested and code as below :</p>

<pre><code>@Autowired
protected JdbcTemplate jdbcTemp;

public List&lt;&gt; getData(String id) {

    return jdbcTemp.query("SELECT ........,new RowMapper());
}
</code></pre>

<p>But getting java.lang.NullPointerException:</p>