How to resolve the error: java.lang.BootstrapMethodError: java.lang.NoClassDefFoundError: io/vertx/core/Promise

Question

i have created a maven project where i wrote code for kafka consumer to retrieve the messages from kafka server. i am using vertx framework with vertx-kafka-client dependency. According to vertx kafka docs ( https://vertx.io/docs/vertx-kafka-client/java/#_using_the_vert_x_kafka_client ), i have setup the code and while running the program i am getting error as java.lang.BootstrapMethodError: java.lang.NoClassDefFoundError: io/vertx/core/Promise

Answer 1

The solution to this error is

• Right-click on your project
• Go to Maven -> Update Project
• After update, Run the program

when we import projects to IDE, sometimes we forget to update the project and directly running it will cause the error.