Spring bean wiring in different contexts

Question

For datasource layer I use the following Spring Configuration file:

@Configuration
@ComponentScan(basePackages = {"com.savdev.springmvcexample.repository", "com.savdev.springmvcexample.config"})
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = {"com.savdev.springmvcexample.repository"})
public class InfrastructureContextConfiguration {
...
    @Configuration
    @Profile(value = "file_based")
    @PropertySource("classpath:/db/config/file_based.properties")
    public static class FileBasedConfiguration {

        @Inject
        private Environment environment;

        @Bean
        public DataSource dataSource() {
            BasicDataSource dataSource = new org.apache.commons.dbcp.BasicDataSource();
            dataSource.setDriverClassName(environment.getProperty("jdbc.driver"));
            dataSource.setUrl(environment.getProperty("jdbc.url"));
            dataSource.setUsername(environment.getProperty("jdbc.username"));
            dataSource.setPassword(environment.getProperty("jdbc.password"));
            return dataSource;
        }
    }
...

To run tests I load this configuration via @ContextConfiguration :

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { InfrastructureContextConfiguration.class, HsqldbEmbeddableDbStarterContextConfiguration.class })
@TransactionConfiguration(transactionManager = "transactionManager", defaultRollback = false)
@Transactional()
@ActiveProfiles(profiles = {"file_based", "test_data"} )
public abstract class AbstractJpaJavaTestBase {
...

And it works fine.

The same InfrastructureContextConfiguration class is used in web module when DispatcherServlet is created:

public class SpringMvcExampleWebApplicationInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        registerDispatcherServlet(servletContext);
    }

    private void registerDispatcherServlet(final ServletContext servletContext) {
        WebApplicationContext dispatcherContext = createContext(WebMvcContextConfiguration.class, InfrastructureContextConfiguration.class);
        DispatcherServlet dispatcherServlet = new DispatcherServlet(dispatcherContext);
        dispatcherServlet.setContextInitializers( new SpringMvcExampleProfilesInitializer());
        ServletRegistration.Dynamic dispatcher;
        dispatcher = servletContext.addServlet("dispatcher", dispatcherServlet);
        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping("/");
    }

    private WebApplicationContext createContext(final Class<?>... annotatedClasses) {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.register(annotatedClasses);
        return context;
    }
}

But now, I'm getting NullPointerException in the following line of InfrastructureContextConfiguration :

dataSource.setDriverClassName(environment.getProperty("jdbc.driver"));

The environment is not wired. What can I do to resolve it?

Answer 1

What I found. The similar issue already have been met: same1, some solutions

seems the problem is not connected, but the last answer is the best solution

total: Actually, the field that is injected with @Inject cannot be null. It must throws exception. As a result if it is null then - the annotation has not been applied at all. As a result the main reason is the absence of its implementation in classpath.

So I added the following in my web.pom. and it resolved the problem:

<dependency>
    <groupId>javax.inject</groupId>
    <artifactId>javax.inject</artifactId>
    <version>1</version>
</dependency>

As alternative options I could use:

1. @Resource instead of @Inject, and environment has been set.

2. Passed the envirionment as argument into the constructor, instead of wiring it via annotation. But the best case, IMHO, is fix jar dependecy.