# Handle an incoming message

 Note:
Before you can get started, you need the following already set up:

- 
- [JDK 8](https://www.oracle.com/java/technologies/downloads/) or later and a familiarity with how to create a new Java application.
- [Gradle](https://gradle.org/install/) and a familiarity with how use the Gradle build tools.
- [ngrok](https://ngrok.com/). You'll use ngrok to open a tunnel to your local server.


Using the Conversation API, you can receive and respond to messages from any channel you have configured. This tutorial shows you how to set up a Java application that receives and responds to messages using the Java SDK.

 Note:
This tutorial is easier to accomplish if you have already completed the steps for [Sending a message](/docs/conversation/getting-started/java/send-message).

Steps:
1. [Set up](#set-up-your-java-application) your Java application
2. [Configure](#configure-your-webhook) your Conversation API webhook
3. [Test](#test-the-application) the application


## Set up your Java application

1. Create a new folder where you want your application project, then open a command prompt to that location.
2. Create a new Java application using Gradle with the following command:

```shell
gradle init
```
In the prompts, select that you want to create an application, name your project and source package `app`, and then accept the defaults for the rest of the options.


### Add the Sinch Java SDK and other dependencies

1. In your project folder, navigate to the `/app` folder and open the `build.gradle` file.
2. Replace all of the code in the file with the following code:

```shell
plugins {
  id 'application'
  id 'org.springframework.boot' version '2.5.5'
  id 'io.spring.dependency-management' version '1.0.11.RELEASE'
  id 'java'
}

configurations {
  compileOnly {
    extendsFrom annotationProcessor
  }
}

repositories {
  mavenCentral()
}

dependencies {
  implementation 'org.springframework.boot:spring-boot-starter-web'
  implementation 'com.sinch.sdk:java-sdk:+'
  compileOnly 'org.projectlombok:lombok'
  annotationProcessor 'org.projectlombok:lombok'
  testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

application {
  mainClass = 'app.App'
}
```
This adds the Sinch Java SDK, Spring, and Lombok to your project. You will use Spring to listen to incoming HTTP requests. Lombok is used to deserialize requests.
3. Save and close the file.


### Modify your application

1. Open the `App.java` file in your project folder, located in `\app\scr\main\java\app`. Populate that file with the "App.java" code found on this page and save the file. This code starts a server that listens for incoming messages. It then sends a [text message](/docs/conversation/message-types/text-message/) in response.

This sample application is configured for the US Region. If your Conversation API app wasn't created in the US region, you must change the `Region.US` parameter to `Region.EU`.
2. Assign your values to the following parameters:
ParameterYour valueACCESS_KEYFind your access key on your Sinch [dashboard](https://dashboard.sinch.com/settings/access-keys).ACCESS_SECRET
     Find your access secret on your Sinch [dashboard](https://dashboard.sinch.com/settings/access-keys).Note:Access secrets are only available during initial key creation.
3. Save the file.


### Start your web server and set up a tunnel

1. In your project directory, start the server by executing the following command:

```shell
gradle run
```
By default, your web server is started on port 8080.
2. Now you need to open a tunnel to the server you just set up. We are using [ngrok](https://ngrok.com/) for this. If you don't have ngrok installed already, install it with the following command:

```shell
npm install ngrok -g
```
3. Open a terminal or command prompt and enter:

```shell
ngrok http 8080
```
4. Copy the HTTPS address that ends with **.ngrok.io**.


## Configure your webhook

For your application to receive messages from Conversation API, you must configure a webhook in your Conversation API app. For detailed instructions on configuring a webhook, click [here](https://community.sinch.com/t5/Conversation-API/How-to-add-a-webhook-to-a-Conversation-API-app/ta-p/8100).

1. Set your webhook URL to the HTTP address you copied in the previous step.
2. Assign the following triggers:
  - `CONVERSATION_START`
  - `CONVERSATION_STOP`
  - `EVENT_DELIVERY`
  - `EVENT_INBOUND`
  - `MESSAGE_DELIVERY`
  - `MESSAGE_INBOUND`
  - `UNSUPPORTED`


## Test the application

Now that your server is running and your webhook is configured, you can test the application.

From your messaging platform, send your Conversation API app a message. You will receive a message back in response on the messaging platform.

## Additional resources

Read the links below to learn more:

- [Learn more about different message types](/docs/conversation/message-types)
- [Learn more about channels](/docs/conversation/channel-support)
- [API specification](/docs/conversation/api-reference/)