I’m trying to test a lambda function (spring boot cloud app), but getting java.lang.ClassNotFoundException eventhough the stream handler is properly mentioned under runtime settings.

Error Message:

{
  "errorMessage": "Class not found: com.myexample.handler.ServiceHandler",
  "errorType": "java.lang.ClassNotFoundException"
}

Here is the stream handler code:

package com.myexample.handler;

@Slf4j
@Component
public class ServiceHandler implements RequestHandler<String,Object> {

    @Autowired
    MyService myService ;

    @Override
    public Object handleRequest(String s, Context context) {
            // myService.executeMethod();
    }

I’m using maven shade plugin to build the jar with all dependencies:

<build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.2.4</version>
                <configuration>
                    <createDependencyReducedPom>false</createDependencyReducedPom>
                    <shadedArtifactAttached>true</shadedArtifactAttached>
                    <shadedClassifierName>aws</shadedClassifierName>
                    <transformers>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                            <resource>META-INF/spring.handlers</resource>
                        </transformer>
                        <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
                            <resource>META-INF/spring.factories</resource>
                        </transformer>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                            <resource>META-INF/spring.schemas</resource>
                        </transformer>
                    </transformers>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Other important maven dependencies added (apart from regular spring boot dependencies) in my project for this purpose:

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-function-adapter-aws</artifactId>
            <version>3.2.5</version>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-core</artifactId>
            <version>1.2.1</version>
        </dependency>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-events</artifactId>
            <version>3.11.0</version>
        </dependency>

Few things to note here is: I’m using @Component annotation in the ServiceHandler class. I had to do this, because I need to autowire the service.

I have no clue what’s going wrong here as I don’t see anything wrong at lambda side as well as the code. Any suggestions would be really appreciated. Thanks!