Question

Why is Android sending this symbol?(�)

What I’m doing is, get a few variables, put them altogether, and then send using Multicast. The symbols occur only in the end of the String, and repeat a lot.

byte[] buffer;

String temp1 = "temp1=" + "37";
String weight1 = "weight1=" + "68";
String bpm = "bpm=" + "128";
String angBack = "angback=" + "90";
String angLeg = "angleg=" + "90";
String angBed = "angbed=" + "91";

String msg = "status:teste," + temp1 + "," + weight1 + "," + bpm + "," + angBack + 
              "," + angLeg + "," + angBed;

buffer = msg.getBytes();

InetAddress group = InetAddress.getByName("230.0.0.1");

DatagramPacket packet = new DatagramPacket(buffer, buffer.length, group, 5556);
socket.send(packet);

Then on the other side, I get the String, and those symbols appear at the end of the String.

byte[] buffer = new byte[256];

DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

multicastSocket.receive(packet);

String msg = new String(packet.getData());

Why is this happening?

Answer 1

This is not a weird symbol it’s just 0x00.
You’re writing whole buffer, check the data length.

String msg = new String(packet.getData(), packet.getOffset(), packet.getLength());