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Ich heruntergeladen einen einfachen Java WebSocket Echo-Server auf meinem PC (Windows 10). Die App läuft auf einem lokalen Tomcat-Server (die IP-Adresse meines PCs lautet 192.168.178.10).Ich brauche Hilfe bei der Verbindung eines ESP8266 mit einem lokalen Java-Server mit Websockets
Um die App in einem Browser starten Sie den Befehl verwendet wird:
http://localhost:8080/echochamber/
Das alles funktioniert gut, wenn ich es über einen Browser verbinden. Wenn ich jedoch eine NodeMCU (ESP8266) verwende, verweigert sie die Verbindung. Ich habe versucht, eine andere externe Website:
Und die NodeMCU funktioniert einwandfrei. Meine erste Vermutung ist, dass ich mich falsch mit meinem lokalen Server verbinde. Aber ich bin jetzt ein bisschen verloren. Warum kann ich keine Verbindung zu meinem lokal laufenden Server herstellen, sondern einfach zu einem externen Server? Wo mache ich einen Fehler?
Vielen Dank im Voraus.
Java-Web-Server-Code
eine Klasse:
package echochamber;
import java.io.IOException;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
/**
* @ServerEndpoint gives the relative name for the end point
* This will be accessed via ws://localhost:8080/EchoChamber/echo
* Where "localhost" is the address of the host,
* "EchoChamber" is the name of the package
* and "echo" is the address to access this class from the server
*/
@ServerEndpoint("/echo")
public class EchoServer {
/**
* @OnOpen allows us to intercept the creation of a new session.
* The session class allows us to send data to the user.
* In the method onOpen, we'll let the user know that the handshake was
* successful.
*/
@OnOpen
public void onOpen(Session session){
System.out.println(session.getId() + " has opened a connection");
try {
session.getBasicRemote().sendText("Connection Established");
} catch (IOException ex) {
ex.printStackTrace();
}
}
/**
* When a user sends a message to the server, this method will intercept the message
* and allow us to react to it. For now the message is read as a String.
*/
@OnMessage
public void onMessage(String message, Session session){
System.out.println("Message from " + session.getId() + ": " + message);
try {
session.getBasicRemote().sendText(message);
} catch (IOException ex) {
ex.printStackTrace();
}
}
/**
* The user closes the connection.
*
* Note: you can't send messages to the client from this method
*/
@OnClose
public void onClose(Session session){
System.out.println("Session " +session.getId()+" has ended");
}
}
und eine HTML-Datei:
<!DOCTYPE html>
<html>
<head>
<title>Echo Chamber</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width">
</head>
<body>
<div>
<input type="text" id="messageinput"/>
</div>
<div>
<button type="button" onclick="openSocket();" >Open</button>
<button type="button" onclick="send();" >Send</button>
<button type="button" onclick="closeSocket();" >Close</button>
</div>
<!-- Server responses get written here -->
<div id="messages"></div>
<!-- Script to utilise the WebSocket -->
<script type="text/javascript">
var webSocket;
var messages = document.getElementById("messages");
function openSocket(){
// Ensures only one connection is open at a time
if(webSocket !== undefined && webSocket.readyState !== WebSocket.CLOSED){
writeResponse("WebSocket is already opened.");
return;
}
// Create a new instance of the websocket
webSocket = new WebSocket("ws://localhost:8080/echochamber/echo");
/**
* Binds functions to the listeners for the websocket.
*/
webSocket.onopen = function(event){
// For reasons I can't determine, onopen gets called twice
// and the first time event.data is undefined.
// Leave a comment if you know the answer.
if(event.data === undefined)
return;
writeResponse(event.data);
};
webSocket.onmessage = function(event){
writeResponse(event.data);
};
webSocket.onclose = function(event){
writeResponse("Connection closed");
};
}
/**
* Sends the value of the text input to the server
*/
function send(){
var text = document.getElementById("messageinput").value;
webSocket.send(text);
}
function closeSocket(){
webSocket.close();
}
function writeResponse(text){
messages.innerHTML += "<br/>" + text;
}
</script>
</body>
</html>
Auf der nodeMCU der Code ich verwende, ist die folgende:
/*
* WebSocketClient.ino
*
* Created on: 24.05.2015
*
*/
#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <WebSocketsClient.h>
#include <Hash.h>
char SSID[] = "********";
char PASSWORD[] = "********";
ESP8266WiFiMulti WiFiMulti;
WebSocketsClient webSocket;
#define USE_SERIAL Serial
#define VERIFY // if defined goes to echo.websocket.org
void webSocketEvent(WStype_t type, uint8_t * payload, size_t length) {
char message[100];
switch (type) {
case WStype_DISCONNECTED:
USE_SERIAL.printf("[WSc] Disconnected!\n");
break;
case WStype_CONNECTED: {
USE_SERIAL.printf("[WSc] Connected to url: %s\n", payload);
// send message to server when Connected
webSocket.sendTXT("Connected");
}
break;
case WStype_TEXT:
USE_SERIAL.printf("[WSc] get text: %s\n", payload);
//send message to server
sprintf(message, "millis count = %d", millis());
webSocket.sendTXT(message);
delay(1000);
break;
case WStype_BIN:
USE_SERIAL.printf("[WSc] get binary length: %u\n", length);
hexdump(payload, length);
// send data to server
// webSocket.sendBIN(payload, length);
break;
}
}
void setup() {
// Serial setup
//USE_SERIAL.begin(921600);
USE_SERIAL.begin(115200);
// output all debug info
USE_SERIAL.setDebugOutput(true);
for (uint8_t t = 4; t > 0; t--) {
USE_SERIAL.printf("[SETUP] BOOT WAIT %d...\n", t);
USE_SERIAL.flush();
delay(1000);
}
// connect to my local WiFi gateway
WiFiMulti.addAP(SSID, PASSWORD);
// WiFi.disconnect();
while (WiFiMulti.run() != WL_CONNECTED) {
delay(100);
}
// server address, port and URL
#ifdef VERIFY
webSocket.begin("echo.websocket.org", 80, "/");
#else
webSocket.begin("192.168.178.10", 80, "/echochamber");
#endif
// initialte our event handler
webSocket.onEvent(webSocketEvent);
// use HTTP Basic Authorization this is optional remove if not needed
// webSocket.setAuthorization("user", "Password");
// try ever 5000 again if connection has failed
webSocket.setReconnectInterval(5000);
webSocket.
}
void loop() {
webSocket.loop();
}
und das ist der Ausgang, wenn ich echo.websocket.org verbinden:
scandone
state: 0 -> 2 (b0)
state: 2 -> 3 (0)
state: 3 -> 5 (10)
add 0
aid 2
cnt
connected with verelec_1, channel 1
dhcp client start...
[SETUP] BOOT WAIT 3...
[SETUP] BOOT WAIT 2...
[SETUP] BOOT WAIT 1...
ip:192.168.178.16,mask:255.255.255.0,gw:192.168.178.1
[WSc] Connected to url:/
[WSc] get text: Connected
[WSc] get text: millis count = 5363
[WSc] get text: millis count = 6480
[WSc] get text: millis count = 7602
[WSc] get text: millis count = 8729
[WSc] get text: millis count = 9854
[WSc] get text: millis count = 10968
[WSc] get text: millis count = 12096
[WSc] get text: millis count = 13243
[WSc] get text: millis count = 14369
[WSc] get text: millis count = 15905
[WSc] get text: millis count = 17021
[WSc] get text: millis count = 18135
[WSc] get text: millis count = 19251
[WSc] get text: millis count = 20365
[WSc] get text: millis count = 21482
[WSc] get text: millis count = 22597
[WSc] get text: millis count = 23712
[WSc] get text: millis count = 24828
[WSc] get text: millis count = 25945
[WSc] get text: millis count = 27059
[WSc] get text: millis count = 28173
[WSc] get text: millis count = 29313
[WSc] get text: millis count = 30427
[WSc] get text: millis count = 31545
[WSc] get text: millis count = 32661
Ihr eigener Server läuft auf Port 8080, aber Sie versuchen, mit Port 80 zu verbinden. –
IT war sicherlich in die richtige Richtung !!!! Änderte auch den Pfad. änderte die Verbindungslinie in: webSocket.begin ("192.168.178.10", 8080, "/ echochamber/echo"); –
@NicoVerduin und jetzt, ist es gelöst oder nicht? –