Not able to inject dependencies inside the AWS Lambda function through Springs framework

Question

I am trying to create a SQS poller inside the AWS Lambda, and I am trying to process the messages fetched from the SQS queue. In this code I am using Spring Framework to inject the dependencies, so for now I am not using Guice or Dagger or creating objects using "new" operator.

But when I declare all the beans in the ApplicationBeans.java file inside the spring folder, none of my beans gets initialized.

My ApplicationBeans.java looks like this:

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Bean;

@Configuration
public class ApplicationBeans
{

@Bean
-----------
-----------
----------
}

And my main class where I need to inject the dependencies looks like these:

import lombok.AllArgsConstructor;
@AllArgsConstructor
public class MainClass implements RequestHandler<SQSEvent, Void>
{
private Dependency1 dependency1;
-----
-----
-----

}

But now when I try to access the dependency1 in the code, it gives me a nullPointer exception. What is going wrong in configuring Springs in AWS Lambda?

Answer 1

In your code here, you have to specify annotations such as

@Autowired

or

@Resource

so that spring realizes to inject bean to it.

import lombok.AllArgsConstructor;
@AllArgsConstructor
public class MainClass implements RequestHandler<SQSEvent, Void>
{
    @Autowired
    private Dependency1 dependency1;
    -----
    -----
    -----
}

If you are not willing to use annotations, then you have to use ApplicationContext class to get the Beans using getBean() method.

Hope this helps!!