enter image description here

Issue: You're encountering the error:

json Copy Edit { "errorMessage": "Class not found: com.effigo.vendor.portal.scheduler.lambda.LambdaCronSchedulerHandler", "errorType": "java.lang.ClassNotFoundException" } This error occurs because the AWS Lambda function cannot locate the LambdaCronSchedulerHandler class when it tries to invoke it, even though you have specified the correct handler in Lambda and have attempted to package your code correctly.

Steps You Have Tried: Packaging as JAR:

You initially attempted to use the Spring Boot Maven Plugin to package your project as a JAR.

However, the Spring Boot structure created a /BOOT-INF folder in the JAR, which AWS Lambda doesn't handle. This caused the ClassNotFoundException.

Switching to Maven Shade Plugin:

You switched to the Maven Shade Plugin in the pom.xml file to package the code into a shaded JAR (fat JAR) for Lambda.

You confirmed that the LambdaCronSchedulerHandler.class was correctly included in the JAR.

Despite this, AWS Lambda could not find the class when invoked.

Correcting the Lambda Handler:

You double-checked that the Lambda handler is configured as:

ruby Copy Edit com.effigo.vendor.portal.scheduler.lambda.LambdaCronSchedulerHandler::handleRequest This seemed correct, but the ClassNotFoundException persisted.

Rebuilding the JAR:

You rebuilt the JAR after switching to the Maven Shade Plugin, but AWS Lambda still threw the same error, indicating it couldn't find the class.

AWS Article Insights:

You referenced the AWS documentation regarding ClassNotFoundException, and this suggested creating a ZIP file with a flat structure, without the Spring Boot JAR packaging.

Creating the ZIP:

You followed instructions to create a ZIP file instead of a JAR, anizing the classes and dependencies into a flat directory structure.

However, the ZIP file was not created in your target/ directory after running the maven-shade-plugin build. The JAR file was still present.

Current State: Lambda still can't find the handler class (LambdaCronSchedulerHandler).

You haven't been able to generate a working ZIP file that AWS Lambda can use to deploy the function.

Potential Issues Identified: Spring Boot Structure in the JAR:

Even though you switched to the Maven Shade Plugin, it might still not be configured correctly to remove the Spring Boot structure.

The Lambda function expects a flat JAR, but Spring Boot plugins might still bundle classes under /BOOT-INF/.

ZIP File Creation:

While you attempted to create a ZIP file, you may not have fully prepared the necessary folder structure for Lambda, or the process to create the ZIP file was incomplete.

enter image description here

Issue: You're encountering the error:

json Copy Edit { "errorMessage": "Class not found: com.effigo.vendor.portal.scheduler.lambda.LambdaCronSchedulerHandler", "errorType": "java.lang.ClassNotFoundException" } This error occurs because the AWS Lambda function cannot locate the LambdaCronSchedulerHandler class when it tries to invoke it, even though you have specified the correct handler in Lambda and have attempted to package your code correctly.

Steps You Have Tried: Packaging as JAR:

You initially attempted to use the Spring Boot Maven Plugin to package your project as a JAR.

However, the Spring Boot structure created a /BOOT-INF folder in the JAR, which AWS Lambda doesn't handle. This caused the ClassNotFoundException.

Switching to Maven Shade Plugin:

You switched to the Maven Shade Plugin in the pom.xml file to package the code into a shaded JAR (fat JAR) for Lambda.

You confirmed that the LambdaCronSchedulerHandler.class was correctly included in the JAR.

Despite this, AWS Lambda could not find the class when invoked.

Correcting the Lambda Handler:

You double-checked that the Lambda handler is configured as:

ruby Copy Edit com.effigo.vendor.portal.scheduler.lambda.LambdaCronSchedulerHandler::handleRequest This seemed correct, but the ClassNotFoundException persisted.

Rebuilding the JAR:

You rebuilt the JAR after switching to the Maven Shade Plugin, but AWS Lambda still threw the same error, indicating it couldn't find the class.

AWS Article Insights:

You referenced the AWS documentation regarding ClassNotFoundException, and this suggested creating a ZIP file with a flat structure, without the Spring Boot JAR packaging.

Creating the ZIP:

You followed instructions to create a ZIP file instead of a JAR, anizing the classes and dependencies into a flat directory structure.

However, the ZIP file was not created in your target/ directory after running the maven-shade-plugin build. The JAR file was still present.

Current State: Lambda still can't find the handler class (LambdaCronSchedulerHandler).

You haven't been able to generate a working ZIP file that AWS Lambda can use to deploy the function.

Potential Issues Identified: Spring Boot Structure in the JAR:

Even though you switched to the Maven Shade Plugin, it might still not be configured correctly to remove the Spring Boot structure.

The Lambda function expects a flat JAR, but Spring Boot plugins might still bundle classes under /BOOT-INF/.

ZIP File Creation:

While you attempted to create a ZIP file, you may not have fully prepared the necessary folder structure for Lambda, or the process to create the ZIP file was incomplete.

• java
• amazon-web-services
• spring-boot
• maven
• aws-lambda

1 Answer 1

Had same problem wit springboot lambda ClassNotFoundException.Worked 4 me after 2 days of pain. Fixed it:

1. Add deps: aws-lambda-java-core + aws-serverless-java-container-springboot2

2. Fix maven-shade-plugin:

<plugin>
  <groupId>.apache.maven.plugins</groupId>
  <artifactId>maven-shade-plugin</artifactId>
  <version>3.2.4</version>
  <configuration>
    <createDependencyReducedPom>false</createDependencyReducedPom>
  </configuration>
  <executions>
    <execution>
      <phase>package</phase>
      <goals><goal>shade</goal></goals>
      <configuration>
        <transformers>
          <transformer implementation=".apache.maven.plugins.shade.resource.ManifestResourceTransformer">
            <mainClass>com.effigo.vendor.portal.scheduler.Application</mainClass>
          </transformer>
          <transformer implementation=".apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
        </transformers>
      </configuration>
    </execution>
  </executions>
</plugin>

3. Make lambda handler outside BOOT-INF:

package com.effigo.vendor.portal.scheduler.lambda;
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;

public class LambdaCronSchedulerHandler implements RequestHandler<Object, String> {
    public String handleRequest(Object input, Context context) {
        // This is where u initialize spring and do ur scheduler stuff

        return "Success";
    }
}

4. Disable web container:

spring.main.web-application-type=none

Worked 4 me after 2 days of pain.