update java doc

Signed-off-by: wanjunlei <wanjunlei@kubesphere.io>

Author: wanjunlei

content/en/docs/concepts/function_signatures.md

@@ -30,5 +30,5 @@ As you can see, `OpenFunction` signature is the recommended function signature,
 | Go        | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-go), [Multi-functions](https://github.com/OpenFunction/samples/tree/main/functions/knative/multiple-functions-go), [Sync function with path parameters](https://github.com/OpenFunction/samples/tree/main/functions/knative/path-parameters-function-go), [log processing](https://github.com/OpenFunction/samples/blob/main/functions/knative/logs-handler-function/LogsHandler.go) | [Sync function with path parameters](https://github.com/OpenFunction/samples/tree/main/functions/knative/path-parameters-function-go) | [Sync function with path parameters](https://github.com/OpenFunction/samples/tree/main/functions/knative/path-parameters-function-go), [Sync function with output binding](https://github.com/OpenFunction/samples/tree/main/functions/knative/with-output-binding), [Kafka input & HTTP output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/logs-handler-function), [Cron input & Kafka output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/cron-input-kafka-output), [Cron input binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/cron-input), [Kafka input binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/kafka-input), [Kafka pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/pubsub) |
 | Nodejs    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-node) |  | [Sync function with output binding](https://github.com/OpenFunction/samples/tree/main/functions/knative/with-output-binding-node), [MQTT binding & pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/mqtt-io-node) |
 | Python    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-python) |  |  |
-| Java      | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-java) |  |  |
+| Java      | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/java/hello-world) | [CloudEvent](https://github.com/OpenFunction/samples/tree/main/functions/knative/java/cloudevent) | [Sync function with output](https://github.com/OpenFunction/samples/tree/main/functions/knative/java/with-output-binding), [Cron input & Kafka output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/java/cron-input-kafka-output), [Kafka pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/java/pubsub) |
 | DotNet    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-dotnet) |  |  |

content/en/docs/getting-started/Quickstarts/async-functions.md

@@ -14,7 +14,7 @@ Async functions are event-driven and their inputs are usually events from Non-HT
 | Go        | [Kafka input & HTTP output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/logs-handler-function), [Cron input & Kafka output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/cron-input-kafka-output), [Cron input binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/cron-input), [Kafka input binding](https://github.com/OpenFunction/samples/tree/main/functions/async/bindings/kafka-input), [Kafka pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/pubsub) |
 | Nodejs    | [MQTT binding & pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/mqtt-io-node) |
 | Python    |  |
-| Java      |  |
+| Java      | [Cron input & Kafka output binding](https://github.com/OpenFunction/samples/tree/main/functions/async/java/cron-input-kafka-output), [Kafka pubsub](https://github.com/OpenFunction/samples/tree/main/functions/async/java/pubsub) |
 | DotNet    |  |
 
 > You can find more function samples [here](../../../concepts/function_signatures/#samples)

content/en/docs/getting-started/Quickstarts/sync-functions.md

@@ -14,7 +14,7 @@ Sync functions are funtions whose inputs are payloads of HTTP requests, and the
 | Go        | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-go), [Multi-functions](https://github.com/OpenFunction/samples/tree/main/functions/knative/multiple-functions-go), [Sync function with path parameters](https://github.com/OpenFunction/samples/tree/main/functions/knative/path-parameters-function-go), [log processing](https://github.com/OpenFunction/samples/blob/main/functions/knative/logs-handler-function/LogsHandler.go), [Sync function with output binding](https://github.com/OpenFunction/samples/tree/main/functions/knative/with-output-binding) |
 | Nodejs    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-node), [Sync function with output binding](https://github.com/OpenFunction/samples/tree/main/functions/knative/with-output-binding-node) |
 | Python    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-python) |
-| Java      | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-java) |
+| Java      | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/java/hello-world), [Sync function with output](https://github.com/OpenFunction/samples/tree/main/functions/knative/java/with-output-binding) |
 | DotNet    | [Hello World](https://github.com/OpenFunction/samples/tree/main/functions/knative/hello-world-dotnet) |
 
 > You can find more function samples [here](../../../concepts/function_signatures/#samples)