BAEL1053 - deep20jain@gmail.com - Broadcasting and Multicasting in Java (#2368)
* Adding code for java broadcasting and multicasting * Changing multicast ip * Adding code to iterate thorugh all network interfaces * Formatting again and fixing bug * Applying formatting rules on all classes * Fixing formatting
This commit is contained in:
deep20jain
Zeger Hendrikse
parent
299432df11
commit
290e759d4a
|
|
@ -0,0 +1,85 @@
|
|||
package com.baeldung.java.networking.udp.broadcast;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.net.DatagramPacket;
|
||||
import java.net.DatagramSocket;
|
||||
import java.net.InetAddress;
|
||||
import java.net.NetworkInterface;
|
||||
import java.net.SocketException;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Enumeration;
|
||||
import java.util.List;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
public class BroadcastingClient {
|
||||
private DatagramSocket socket;
|
||||
private InetAddress address;
|
||||
private int expectedServerCount;
|
||||
private byte[] buf;
|
||||
|
||||
public BroadcastingClient(int expectedServerCount) throws Exception {
|
||||
this.expectedServerCount = expectedServerCount;
|
||||
this.address = InetAddress.getByName("255.255.255.255");
|
||||
}
|
||||
|
||||
public int discoverServers(String msg) throws IOException {
|
||||
initializeSocketForBroadcasting();
|
||||
copyMessageOnBuffer(msg);
|
||||
|
||||
// When we want to broadcast not just to local network, call listAllBroadcastAddresses() and execute broadcastPacket for each value.
|
||||
broadcastPacket(address);
|
||||
|
||||
return receivePackets();
|
||||
}
|
||||
|
||||
List<InetAddress> listAllBroadcastAddresses() throws SocketException {
|
||||
List<InetAddress> broadcastList = new ArrayList<>();
|
||||
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
|
||||
while (interfaces.hasMoreElements()) {
|
||||
NetworkInterface networkInterface = interfaces.nextElement();
|
||||
|
||||
if (networkInterface.isLoopback() || !networkInterface.isUp()) {
|
||||
continue;
|
||||
}
|
||||
|
||||
broadcastList.addAll(networkInterface.getInterfaceAddresses()
|
||||
.stream()
|
||||
.filter(address -> address.getBroadcast() != null)
|
||||
.map(address -> address.getBroadcast())
|
||||
.collect(Collectors.toList()));
|
||||
}
|
||||
return broadcastList;
|
||||
}
|
||||
|
||||
private void initializeSocketForBroadcasting() throws SocketException {
|
||||
socket = new DatagramSocket();
|
||||
socket.setBroadcast(true);
|
||||
}
|
||||
|
||||
private void copyMessageOnBuffer(String msg) {
|
||||
buf = msg.getBytes();
|
||||
}
|
||||
|
||||
private void broadcastPacket(InetAddress address) throws IOException {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length, address, 4445);
|
||||
socket.send(packet);
|
||||
}
|
||||
|
||||
private int receivePackets() throws IOException {
|
||||
int serversDiscovered = 0;
|
||||
while (serversDiscovered != expectedServerCount) {
|
||||
receivePacket();
|
||||
serversDiscovered++;
|
||||
}
|
||||
return serversDiscovered;
|
||||
}
|
||||
|
||||
private void receivePacket() throws IOException {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length);
|
||||
socket.receive(packet);
|
||||
}
|
||||
|
||||
public void close() {
|
||||
socket.close();
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,44 @@
|
|||
package com.baeldung.java.networking.udp.broadcast;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.net.DatagramPacket;
|
||||
import java.net.DatagramSocket;
|
||||
import java.net.InetAddress;
|
||||
import java.net.InetSocketAddress;
|
||||
|
||||
public class BroadcastingEchoServer extends Thread {
|
||||
|
||||
protected DatagramSocket socket = null;
|
||||
protected boolean running;
|
||||
protected byte[] buf = new byte[256];
|
||||
|
||||
public BroadcastingEchoServer() throws IOException {
|
||||
socket = new DatagramSocket(null);
|
||||
socket.setReuseAddress(true);
|
||||
socket.bind(new InetSocketAddress(4445));
|
||||
}
|
||||
|
||||
public void run() {
|
||||
running = true;
|
||||
|
||||
while (running) {
|
||||
try {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length);
|
||||
socket.receive(packet);
|
||||
InetAddress address = packet.getAddress();
|
||||
int port = packet.getPort();
|
||||
packet = new DatagramPacket(buf, buf.length, address, port);
|
||||
String received = new String(packet.getData(), 0, packet.getLength());
|
||||
if (received.equals("end")) {
|
||||
running = false;
|
||||
continue;
|
||||
}
|
||||
socket.send(packet);
|
||||
} catch (IOException e) {
|
||||
e.printStackTrace();
|
||||
running = false;
|
||||
}
|
||||
}
|
||||
socket.close();
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,41 @@
|
|||
package com.baeldung.java.networking.udp.multicast;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.net.DatagramPacket;
|
||||
import java.net.InetAddress;
|
||||
import java.net.MulticastSocket;
|
||||
|
||||
public class MulticastEchoServer extends Thread {
|
||||
|
||||
protected MulticastSocket socket = null;
|
||||
protected byte[] buf = new byte[256];
|
||||
protected InetAddress group = null;
|
||||
|
||||
public MulticastEchoServer() throws IOException {
|
||||
socket = new MulticastSocket(4446);
|
||||
socket.setReuseAddress(true);
|
||||
group = InetAddress.getByName("230.0.0.0");
|
||||
socket.joinGroup(group);
|
||||
}
|
||||
|
||||
public void run() {
|
||||
try {
|
||||
while (true) {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length);
|
||||
socket.receive(packet);
|
||||
InetAddress address = packet.getAddress();
|
||||
int port = packet.getPort();
|
||||
packet = new DatagramPacket(buf, buf.length, address, port);
|
||||
String received = new String(packet.getData(), 0, packet.getLength());
|
||||
if (received.equals("end")) {
|
||||
break;
|
||||
}
|
||||
socket.send(packet);
|
||||
}
|
||||
socket.leaveGroup(group);
|
||||
socket.close();
|
||||
} catch (IOException e) {
|
||||
e.printStackTrace();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,53 @@
|
|||
package com.baeldung.java.networking.udp.multicast;
|
||||
|
||||
import java.io.IOException;
|
||||
import java.net.DatagramPacket;
|
||||
import java.net.DatagramSocket;
|
||||
import java.net.InetAddress;
|
||||
|
||||
public class MulticastingClient {
|
||||
private DatagramSocket socket;
|
||||
private InetAddress group;
|
||||
private int expectedServerCount;
|
||||
private byte[] buf;
|
||||
|
||||
public MulticastingClient(int expectedServerCount) throws Exception {
|
||||
this.expectedServerCount = expectedServerCount;
|
||||
this.socket = new DatagramSocket();
|
||||
this.group = InetAddress.getByName("230.0.0.0");
|
||||
}
|
||||
|
||||
public int discoverServers(String msg) throws IOException {
|
||||
copyMessageOnBuffer(msg);
|
||||
multicastPacket();
|
||||
|
||||
return receivePackets();
|
||||
}
|
||||
|
||||
private void copyMessageOnBuffer(String msg) {
|
||||
buf = msg.getBytes();
|
||||
}
|
||||
|
||||
private void multicastPacket() throws IOException {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
|
||||
socket.send(packet);
|
||||
}
|
||||
|
||||
private int receivePackets() throws IOException {
|
||||
int serversDiscovered = 0;
|
||||
while (serversDiscovered != expectedServerCount) {
|
||||
receivePacket();
|
||||
serversDiscovered++;
|
||||
}
|
||||
return serversDiscovered;
|
||||
}
|
||||
|
||||
private void receivePacket() throws IOException {
|
||||
DatagramPacket packet = new DatagramPacket(buf, buf.length);
|
||||
socket.receive(packet);
|
||||
}
|
||||
|
||||
public void close() {
|
||||
socket.close();
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,39 @@
|
|||
package com.baeldung.java.networking.udp.broadcast;
|
||||
|
||||
import org.junit.After;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.IOException;
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
public class BroadcastIntegrationTest {
|
||||
private BroadcastingClient client;
|
||||
|
||||
@Test
|
||||
public void whenBroadcasting_thenDiscoverExpectedServers() throws Exception {
|
||||
int expectedServers = 4;
|
||||
initializeForExpectedServers(expectedServers);
|
||||
|
||||
int serversDiscovered = client.discoverServers("hello server");
|
||||
assertEquals(expectedServers, serversDiscovered);
|
||||
}
|
||||
|
||||
private void initializeForExpectedServers(int expectedServers) throws Exception {
|
||||
for (int i = 0; i < expectedServers; i++) {
|
||||
new BroadcastingEchoServer().start();
|
||||
}
|
||||
|
||||
client = new BroadcastingClient(expectedServers);
|
||||
}
|
||||
|
||||
@After
|
||||
public void tearDown() throws IOException {
|
||||
stopEchoServer();
|
||||
client.close();
|
||||
}
|
||||
|
||||
private void stopEchoServer() throws IOException {
|
||||
client.discoverServers("end");
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,39 @@
|
|||
package com.baeldung.java.networking.udp.multicast;
|
||||
|
||||
import org.junit.After;
|
||||
import org.junit.Test;
|
||||
|
||||
import java.io.IOException;
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
public class MulticastIntegrationTest {
|
||||
private MulticastingClient client;
|
||||
|
||||
@Test
|
||||
public void whenBroadcasting_thenDiscoverExpectedServers() throws Exception {
|
||||
int expectedServers = 4;
|
||||
initializeForExpectedServers(expectedServers);
|
||||
|
||||
int serversDiscovered = client.discoverServers("hello server");
|
||||
assertEquals(expectedServers, serversDiscovered);
|
||||
}
|
||||
|
||||
private void initializeForExpectedServers(int expectedServers) throws Exception {
|
||||
for (int i = 0; i < expectedServers; i++) {
|
||||
new MulticastEchoServer().start();
|
||||
}
|
||||
|
||||
client = new MulticastingClient(expectedServers);
|
||||
}
|
||||
|
||||
@After
|
||||
public void tearDown() throws IOException {
|
||||
stopEchoServer();
|
||||
client.close();
|
||||
}
|
||||
|
||||
private void stopEchoServer() throws IOException {
|
||||
client.discoverServers("end");
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue