项目地址：https://github.com/SunnyLine/Android-Socket-ChatRoom
部分截图：
以下为代码逻辑部分
Java: 监听某个端口，有用户访问时，将这个Socket放入到一个集合中作为一个用户组，并监听这个Socket的消息。收到任意一个Socket的消息后，再将此消息分发给用户组的每一个成员。
Android：使用Socket连接指定IP指定端口，连接成功后发送一条信息给服务器，服务器会将之转发给其他人，其他人就可以知道组内有新用户加入的信息。离开此页面时也要发送给服务器一条离开的信息，服务器会告知其他用户。在子线程中监听服务器发送的数据进行显示。
Java代码如下：
public class Main {
private static final int PORT = 9999;
private static List<Socket> mList = new ArrayList<Socket>();
private static ServerSocket server = null;
private static ExecutorService mExecutorService = null; //thread pool
public static void main(String[] args) {
try {
server = new ServerSocket(PORT);
mExecutorService = Executors.newCachedThreadPool(); //create a thread pool
System.out.println("服务器已启动...");
Socket client = null;
while(true) {
client = server.accept();
//把客户端放入客户端集合中
mList.add(client);
mExecutorService.execute(new Service(client)); //start a new thread to handle the connection
}
}catch (Exception e) {
e.printStackTrace();
}
}
static class Service implements Runnable {
private Socket socket;
private BufferedReader in = null;
private String msg = "";
public Service(Socket socket) {
this.socket = socket;
try {
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
//客户端只要一连到服务器，便向客户端发送下面的信息。
} catch (IOException e) {
e.printStackTrace();
}
}
public byte[] readStream(InputStream inStream) throws Exception {
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = -1;
while ((len = inStream.read(buffer)) != -1) {
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return outSteam.toByteArray();
}
@Override
public void run() {
try {
while(true) {
if((msg = in.readLine())!= null) {
System.out.println("接收:"+msg);
ChatBean bean = new Gson().fromJson(msg, ChatBean.class);
//当客户端发送的信息为：exit时，关闭连接
if(bean.content.equals("exit")) {
System.out.println("用戶:"+bean.name+"已退出谈论组");
mList.remove(socket);
in.close();
socket.close();
this.sendmsg();
break;
//接收客户端发过来的信息msg，然后发送给客户端。
} else {
this.sendmsg();
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 循环遍历客户端集合，给每个客户端都发送信息。
* 可以使用观察者模式设计讨论组
*/
public void sendmsg() {
System.out.println(msg);
int num =mList.size();
for (int index = 0; index < num; index ++) {
Socket mSocket = mList.get(index);
PrintWriter pout = null;
try {
pout = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(mSocket.getOutputStream())),true);
pout.println(msg);
}catch (IOException e) {
e.printStackTrace();
}
}
}
}
}Android 部分代码如下：
public interface ChatView {
public String getHost();
public String getProt();
public String getUserId();
public void showDiaolg(String msg);
public void receiveMsg(ChatBean bean);
}
public class SocketThread extends Thread {
private Socket socket = null;
private BufferedReader in = null;
private PrintWriter out = null;
private ChatView chatView;
public SocketThread(ChatView chatView) {
this.chatView = chatView;
}
private void init() {
try {
socket = new Socket(chatView.getHost(), Integer.parseInt(chatView.getProt()));
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
if (!socket.isOutputShutdown()) {
ChatBean bean = new ChatBean("join", chatView.getUserId());
out.println(new Gson().toJson(bean));
}
} catch (UnknownHostException e1) {
e1.printStackTrace();
mHandler.sendEmptyMessage(-1);
} catch (IOException ex) {
ex.printStackTrace();
mHandler.sendEmptyMessage(0);
} catch (IllegalArgumentException e2) {
e2.printStackTrace();
mHandler.sendEmptyMessage(-2);
}
}
public void sendMsg(String msg) {
ChatBean bean = new ChatBean(msg, chatView.getUserId());
if (!TextUtils.isEmpty(msg) && socket != null && socket.isConnected()) {
if (!socket.isOutputShutdown()) {
out.println(new Gson().toJson(bean));
}
}
}
//接收线程发送过来信息，并用TextView显示
public Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case -2:
chatView.showDiaolg("IllegalArgumentException");
break;
case -1:
chatView.showDiaolg("UnknownHostException");
break;
case 0:
chatView.showDiaolg("IOException");
break;
case 1:
String content = (String) msg.obj;
ChatBean bean = new Gson().fromJson(content, ChatBean.class);
chatView.receiveMsg(bean);
break;
}
}
};
@Override
public void run() {
super.run();
init();
//接收服务器的信息
try {
while (true) {
if (!socket.isClosed()) {
if (socket.isConnected()) {
if (!socket.isInputShutdown()) {
String content;
if ((content = in.readLine()) != null) {
content += "\n";
Message message = mHandler.obtainMessage();
message.obj = content;
message.what = 1;
mHandler.sendMessage(message);
} else {
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}