JNDI in Spring Boot with optional Embedded Tomcat Container

Question

I am rather new to spring boot and have implemented a way of placing a datasource in JNDI context by following the advice given in How to create JNDI context in Spring Boot with Embedded Tomcat Container

I got it to work by adding these beans to the application, which enable naming and place the datasource in JNDI-context like this:

@Autowired
Environment env;

public static void main(final String[] args) {
 SpringApplication.run(MyApplication.class, args);
}


@Bean
public TomcatEmbeddedServletContainerFactory tomcatFactory() {
return new TomcatEmbeddedServletContainerFactory(){

  @Override
  public TomcatEmbeddedServletContainer getTomcatEmbeddedServletContainer(final Tomcat tomcat) {
    tomcat.enableNaming();
    return super.getTomcatEmbeddedServletContainer(tomcat);
  }

  @Override
  public void postProcessContext(final Context context) {
    final String dataSourceURL = env.getProperty("datasource.url");
    // more properties

    final ContextResource resource = new ContextResource();
    resource.setType(DataSource.class.getName());
    resource.setProperty("url", dataSourceURL);
    // more properties

    resource.setName("jdbc/myDB");
    resource.setAuth("Container");
    resource.setType("javax.sql.DataSource");
    resource.setScope("Sharable");

    resource.setProperty("factory", "org.apache.commons.dbcp.BasicDataSourceFactory");

    context.getNamingResources().addResource(resource);
  }
};
}

@Bean(destroyMethod = "")
public DataSource jndiDataSource() throws IllegalArgumentException, NamingException {
  final JndiObjectFactoryBean bean = new JndiObjectFactoryBean();
  bean.setJndiName("java:comp/env/jdbc/myDB");
  bean.setProxyInterface(DataSource.class);
  bean.setLookupOnStartup(false);
  bean.afterPropertiesSet();
  return (DataSource)bean.getObject();
}

So far so good, it worked. But now the specification of the project has changed. In addition of delivering a fat JAR that starts up an embedded Tomcat (as initially planned), I need to be able to deliver a WAR that has no references to the embedded Tomcat. So i created extra projects for packaging and handled the optional inclusion of embedded Tomcat via Maven dependencies. Problem is, I had to move the code that is shown above out of my main class and into a seperate package which i include via Maven dependency. And now it no longer does the trick.

I admit that I am not too familiar with how the Spring-magic with @Autowired and @Bean works, so I am kind off stumbling around here.

What do i have to do to make the creation of JNDI context work outside of my main class?

Don't.. Just don't... Let the user decide. Just create a WAR file (which is as executable as the jar) and if people want to use JNDI bound datasource specify the spring.dataosurce.jndi-name property else configure the database using the other spring.datasoure properties. Don't try to shoehorn all that into embedded tomcat with JNDI as that makes things way too complex. — M. Deinum
Wouldn't I still have to enable naming to do that? Seems to me it would fall back to the same problem. — BFR
I´m still not sure i understand. You suggest to not use JNDI at all or make it optional? The problem is that i´m reusing an old, established persistence-layer which requires the datasource to be placed in JNDI, so i can't avoid it. Would you mind elaborating on your suggestion? — BFR
Judging from your configuration it requires a DataSource where it comes from shouldn't matter. Spring boot supports either. — M. Deinum

BFR BFR · Accepted Answer · 2019-02-06T16:19:49

The solution turned out to be quite simple and i could find it by learning more about spring beans. I created another class in which the beans were created, annotated it with @Configuration and added it to the @ComponentScan specification of the main class. Looks like this:

@ComponentScan(basePackages = {"myBasePackage",
                           "externalPackageContainingConfiguration"})

externalPackageContainingConfiguration is only found when it´s artifact is added via Maven Dependency. A little hacky, but does the trick.

JNDI in Spring Boot with optional Embedded Tomcat Container

1 Answers