问题
I am working on websocket communication with Autobahn. On the main.class of my app, I set to call 'connect()' when users click a button.
// Toggle Button event
tButton = (ToggleButton) findViewById(R.id.toggleButton1);
tButton.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
if(isChecked){
}else{
}
}
});
And after that, there is MyOffers.class, and if this class is accessed, MyOffers_Fragment class is produced four times automatically, because MyOffers.class contains 'carousel view' and there are four products.
On 'MyOffers_Fragment' class, when users click one of the image of products, message should be sent.
if (pos == 0) {
product_photo.setImageResource(R.drawable.myoffers_0);
product_photo.setOnClickListener(new ImageButton.OnClickListener(){
public void onClick(View v){
String id = "Product0";
Log.d(TAG, "Current product is : " + id);
A.sendMessage(id);
}
});
}
But 'mConnection.sendTextMessage(id1);' this line makes 'NullPointerException' error. There is a class 'Websocket_Connector.class'
public class WebSocket_Connector {
private static final String TAG = "ECHOCLIENT";
public final WebSocketConnection mConnection = new WebSocketConnection();
public void connect(final String wsuri) {
Log.d(TAG, "Connecting to: " + wsuri);
try {
mConnection.connect(wsuri, new WebSocketHandler() {
@Override
public void onOpen() {
Log.d(TAG, "Status: Connected to " + wsuri );
Log.d(TAG, "Connection successful!\n");
}
@Override
public void onTextMessage(String payload) {
Log.d(TAG, "Got echo: " + payload);
}
@Override
public void onClose(int code, String reason) {
Log.d(TAG, "Connection closed.");
}
});
} catch (WebSocketException e) {
Log.d(TAG, e.toString());
}
public void sendMessage(String message) {
connect("ws://192.168.x.xxx:xxxx");
mConnection.sendTextMessage(message);
}
}
I called 'connect()' in the main page class, and after that try to send message. But, it's not working..Can you please help me out?
回答1:
public class WebSocket_Connector {
private static final String TAG = "ECHOCLIENT";
public final WebSocketConnection mConnection = new WebSocketConnection();
private String tmpString = "";
public void connect(final String wsuri) {
Log.d(TAG, "Connecting to: " + wsuri);
try {
mConnection.connect(wsuri, new WebSocketHandler() {
@Override
public void onOpen() {
Log.d(TAG, "Status: Connected to " + wsuri );
Log.d(TAG, "Connection successful!\n");
mConnection.sendTextMessage(tmpString);
tmpString = "";
}
@Override
public void onTextMessage(String payload) {
Log.d(TAG, "Got echo: " + payload);
}
@Override
public void onClose(int code, String reason) {
Log.d(TAG, "Connection closed.");
}
});
} catch (WebSocketException e) {
Log.d(TAG, e.toString());
}
public void sendMessage(String message) {
if (mConnection.isConnected())
mConnection.sendTextMessage(message);
else {
tmpString = message;
connect("ws://192.168.x.xxx:xxxx");
}
}
}
来源：https://stackoverflow.com/questions/17190843/android-autobahn-websocket-sending-message-errornullpointerexception