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Spring

eventmesh-connector-spring is a Spring Boot starter, not a standalone main() connector. Add the module to a Spring Boot application. EventMeshAutoConfiguration registers the source, sink, and connect-server beans.

The source takes objects from your application (SpringSourceConnector.send) and publishes them to EventMesh. The sink takes events from EventMesh and delivers them to methods annotated with @EventMeshListener.

SpringSinkConnector: From EventMesh to Spring​

  1. Start EventMesh Runtime.
  2. Enable the sink (sinkEnable: true in server-config.yml) and check sink-config.yml.
  3. Start the Spring Boot application that depends on eventmesh-connector-spring. EventMeshListenerBeanPostProcessor starts SpringSinkConnector and invokes each @EventMeshListener method with records from the sink queue.
  4. Send a message to EventMesh on pubSubConfig.subject; the listener method receives it.
@Component
public class SpringSubHandler {

    @EventMeshListener
    public void onMessage(String message) {
        // handle payload
    }
}
pubSubConfig:
  meshAddress: 127.0.0.1:10000
  subject: TEST-TOPIC-SPRING
  idc: FT
  env: PRD
  group: springSink
  appId: 5033
  userName: springSinkUser
  passWord: springPassWord
sinkConnectorConfig:
  connectorName: springSink

SpringSourceConnector: From Spring to EventMesh​

  1. Start EventMesh Runtime.
  2. Enable the source (sourceEnable: true in server-config.yml) and check source-config.yml.
  3. Start the Spring Boot application. SpringConnectServer (a CommandLineRunner) starts SpringSourceConnector. Inject that bean and call send.
  4. The payload is published to pubSubConfig.subject in EventMesh Runtime.
@RestController
public class SpringPubController {

    @Autowired
    private SpringSourceConnector springSourceConnector;

    @RequestMapping("/spring/pub")
    public String publish() {
        springSourceConnector.send("{\"content\":\"testSpringPublishMessage\"}");
        return "success!";
    }
}
pubSubConfig:
  meshAddress: 127.0.0.1:10000
  subject: TEST-TOPIC-SPRING
  idc: FT
  env: PRD
  group: springSource
  appId: 5033
  userName: springSourceUser
  passWord: springPassWord
sourceConnectorConfig:
  connectorName: springSource

Configuration​

pubSubConfig is the EventMesh TCP client used to publish into or subscribe from Runtime.

sourceConnectorConfig / sinkConnectorConfig fields:

  • connectorName: name of the connector.

server-config.yml:

  • sourceEnable: start SpringSourceConnector from SpringConnectServer.
  • sinkEnable: start SpringSinkConnector from EventMeshListenerBeanPostProcessor.

@EventMeshListener.requestTimeout is the queue poll timeout in seconds (default 5).

Spring environment properties whose keys start with eventmesh.connector. are copied onto source records as extensions (prefix stripped, key lowercased).

Precautions​

  • This module cannot run on its own. Depend on it from a Spring Boot application (META-INF/spring.factories auto-configuration).
  • Bundled server-config.yml sets sourceEnable: true and sinkEnable: true. Turn off the side you are not running.
  • Bundled source-config.yml / sink-config.yml use a connectorConfig key. Jackson binds sourceConnectorConfig and sinkConnectorConfig on the Java config classes; use those field names.
  • SpringConnectServer starts only the source worker. The sink worker is started by EventMeshListenerBeanPostProcessor, not by SpringConnectServer.
  • @EventMeshListener methods must take exactly one argument. String receives the payload bytes as text; any other type is JSON-deserialized.
  • See eventmesh-examples (SpringPubController / SpringSubHandler) for a full sample.

Official references​