👀 Views: 73 💬 Answers: 1 📅 Created: 2025-08-27

gcp dataflow apache-beam Java

I'm working through a tutorial and I'm trying to execute a Dataflow job using Apache Beam version 2.41.0 with Java, but I'm working with a `NoSuchMethodError`. The behavior occurs when I attempt to run the job after defining a transform that uses a custom function for processing elements. The stack trace indicates that it want to find a method that I am certain is present in my code. Here is a snippet of my `DoFn` implementation: ```java public class MyTransform extends DoFn<String, String> { @ProcessElement public void processElement(ProcessContext c) { String input = c.element(); String output = processInput(input); c.output(output); } private String processInput(String input) { // Custom processing logic return input.toUpperCase(); } } ``` I am applying this transform in my pipeline as follows: ```java PCollection<String> output = input.apply("MyUpperCaseTransform", ParDo.of(new MyTransform())); ``` However, when I run the job, I receive the following behavior message in the logs: ``` Exception in thread "main" java.lang.NoSuchMethodError: 'java.lang.String com.example.MyTransform.processInput(java.lang.String)' ``` I've tried cleaning and rebuilding my project, checking for dependency conflicts in my `pom.xml`, and ensuring that the `processInput` method is correctly defined and accessible. My Maven dependencies look like this: ```xml <dependency> <groupId>org.apache.beam</groupId> <artifactId>beam-sdks-java-core</artifactId> <version>2.41.0</version> </dependency> ``` I'm deploying the job using the command line with the following command: ```bash mvn compile exec:java -Dexec.mainClass=com.example.MyDataflowJob ``` I'm unsure why the method want to be found, especially since it compiles without issues. Any insights on how I can resolve this `NoSuchMethodError` or what might be causing it would be greatly appreciated. This is my first time working with Java 3.11. I'd love to hear your thoughts on this. I'd love to hear your thoughts on this.