Java EE 7 SDK

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# The Echo WebSocket Sample Application

This sample is a Hello world application using the Java API for WebSocket.

## Description

This sample shows how to use the annotations in the Java API for WebSocket (JSR 356) to create a simple WebSocket endpoint. The class `EchoEndpoint` is a very simple endpoint: it sends back every incoming text message. You can access the endpoint from the `index.html` page included in this sample. This page contains a very simple JavaScript client that sends the contents of a text field to the server and shows the response on the page.

## Key Features

This sample demonstrates the following key features:

- Creating a simple WebSocket endpoint using the following annotations:

  - `@ServerEndpoint`
  - `@OnMessage`
- Connecting to a WebSocket endpoint from an HTML page using JavaScript.

## Building, Deploying, and Running the Application

Perform the following steps to build, deploy, and run the application:

1. Set up your build environment and configure the application server with which the build system has to work by following the common build instructions.
2. `app_dir` is the sample application base directory: `samples_install_dir/javaee7/websocket/echo`.
3. Build, deploy, and run the sample application using the `run` outcome.

   `mvn clean verify cargo:run`

4. Front page of this sample is at `http://localhost:8080/websocket-echo`.
   (The port number might vary.)
5. Use the `clean` outcome to undeploy the sample application and to remove the temporary directories such as `build` and `dist`.

   `mvn clean`

## Troubleshooting

If you have problems when running the application, refer to the troubleshooting document.

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