kafkatool2.zip

This example shows how to build a custom message decorator for Kafka Tool. This allows you to view messages that are not natively understood by Kafka Tool, in a format that you see fit. For example, one can write a decorator for Avro (or Thrift) messages that will show the actual contents of the Avro objects in a suitable format. The provided example is a simple decorator that shows the checksum of the message bytes. The source code is located in the 'src' directory. Developing ---------- You need to create a class that implements the com.kafkatool.external.ICustomMessageDecorator interface. The interface is located in the 'src' directory and it has two methods that you need to implement public String getDisplayName(); -This method should return a name that will be shown in the Kafka Tool's topic configuration screen where you can pick the content type for the selected topic. public String decorate(String zookeeperHost, String brokerHost, String topic, long partitionId, long offset, byte[] msg, Map<String, String> reserved); -This method does the actual conversion from a byte array to a String that contains the desired output. The String may contain newlines. You should not throw any exceptions from this method, you should catch all throwables in a try/catch block in your implementation. The 'reserved' argument is currently used but may contain data in future releases. Compiling --------- You must compile your source code using Java 8 compatible compiler. The example 'compile.cmd' command can be used as a starting point. Packaging --------- You must put your own compiled classes and any dependencies you might have (e.g. Avro libraries) into a SINGLE jar. Do not include any jars that are already in the 'lib' directory of Kafka Tool, especially any Apache Kafka jars. You can use the sample 'buildJar.cmd' command as a starting point. Usage ----- Once you have compiled and packaged your jar, copy it to the 'plugins' folder in the Kafka Tool installation folder. Restart Kafka Tool and navigate to the topic that you want to use the decorator with. In the 'Content Types' drop-downs you should see the name of your decorator. Select it and click on 'Update'. After that, the messages/keys will be decorated using your custom decorator.