Android聊天工具基于socket实现

特简单， 没有数据库， 还没有处理各种异常。
登录：输入用户名点击的登录即可。
发送消息： 特定格式->toUser:message
1. 服务器：保存在线用户    

public class Online {
 private static Online mOnline = null;
 private LinkedHashMap<String, Socket> mOnlines = new LinkedHashMap<String, Socket>();

 private Online() {
 }

 public synchronized static Online getInstance() {
  if(null == mOnline) {
   mOnline = new Online();
  }

  return mOnline;
 }

 public void put(String key, Socket socket) {
  if(!mOnlines.containsKey(key)) {
   mOnlines.put(key, socket);
  }
 }

 public Socket get(String key) {
  return mOnlines.get(key);
 }

 public void remove(String key) {
  mOnlines.remove(key);
 }
}

2. 服务器：一个简单的socket服务器    

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

// login:uid
// send:fromuser:touser:message
// logout:uid
public class Server implements Runnable {
 private Socket mSocket;
 private Online mOnline;

 public Server(Socket socket) {
  mSocket = socket;
  mOnline = Online.getInstance();
 }

 @Override
 public void run() {
  try {
   BufferedReader reader = new BufferedReader(new InputStreamReader(
     mSocket.getInputStream()));
   String cmd = reader.readLine();

   // login
   if (cmd.startsWith("login")) {
    String userName = cmd.split(":")[1];
    mOnline.put(userName, mSocket);
    System.out.println(userName + " login...");

    PrintWriter writer = new PrintWriter(mSocket.getOutputStream());
    writer.println("success");
    writer.flush();
   } else if (cmd.startsWith("send")) {
    System.out.println(cmd);
    String[] cmds = cmd.split(":");
    String from = cmds[1];
    Socket to = mOnline.get(cmds[2]);
    String msg = cmds[3];

    PrintWriter writer = new PrintWriter(to.getOutputStream());
    System.out.println("rec:" + from + ":" + cmds[2] + ":" + msg);

    writer.println("rec:" + from + ":" + cmds[2] + ":" + msg);
    writer.flush();
   }else if (cmd.startsWith("logout")) {
    System.out.println(cmd);

    String user = cmd.split(":")[1];
    mOnline.get(user).close();
    mOnline.remove(user);

    PrintWriter writer = new PrintWriter(mSocket.getOutputStream());
    writer.println("success");
    writer.flush();
   }
  } catch (Exception e) {
   e.printStackTrace();
  }
 }

 public static void main(String[] args) throws Exception {
  ServerSocket server = new ServerSocket(8888);
  boolean flag = true;
  while (flag) {
   new Thread(new Server(server.accept())).start();
   System.out.println("user in...");
  }

  server.close();
 }
}

3. 客户端登录界面    

public class MainActivity extends Activity {
 private EditText mUser;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  mUser = (EditText) findViewById(R.id.username);
 }

 public void login(View view) {
  final String userName = mUser.getText().toString().trim();
  Login login = new Login(userName);
  login.setOnLoginListener(new Login.LoginCallback() {
   @Override
   public void onLogin(boolean success) {
    if(success) {
     Intent intent = new Intent(MainActivity.this, Chat.class);
     intent.putExtra("user", userName);
     startActivity(intent);
     finish();
    }else {
     Toast.makeText(MainActivity.this, "登录失败", Toast.LENGTH_SHORT).show();
    }
   }
  });

  login.login();
 }
}

4. 处理登录    

public class Login {
 private String mUserName;
 private LoginCallback mCallback;

 public Login(String userName) {
  mUserName = userName;
 }

 public void setOnLoginListener(LoginCallback callback) {
  mCallback = callback;
 }

 private Handler mHandler = new Handler() {
  public void handleMessage(Message msg) {
   switch (msg.what) {
   case Constant.SUCCESS:
    mCallback.onLogin(true);
    break;
   case Constant.FAILED:
    mCallback.onLogin(false);
    break;
   }
  };
 };

 public void login() {
  new Thread(new Runnable() {
   @Override
   public void run() {
    Socket socket = null;
    try {
     socket = new Socket();
     socket.connect(new InetSocketAddress("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter(socket.getOutputStream());
     writer.println("login:" + mUserName);
     writer.flush();

     BufferedReader reader = new BufferedReader(
       new InputStreamReader(socket.getInputStream()));
     String line = reader.readLine();
     System.out.println(line);
     if("success".equals(line)) {
      PConnection.socket = socket;
      mHandler.sendEmptyMessage(Constant.SUCCESS);
     }else {
      mHandler.sendEmptyMessage(Constant.FAILED);
     }
    }catch(Exception e) {
     e.printStackTrace();
    }
   }
  }).start();
 }

 public interface LoginCallback {
  public void onLogin(boolean success);
 }
}

5. 聊天界面    

public class Chat extends Activity {
 private String mUserName;
 private EditText mEdit;
 private ListView mMessage;

 private ReceiverMessage mRecMessage;
 private SendMessage mSendMesage;
 private List<Map<String, String>> mData = new ArrayList<Map<String, String>>();
 private MessagesAdapter mAdapter;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.chat_layout);

  mUserName = getIntent().getStringExtra("user");
  mEdit = (EditText) findViewById(R.id.edit);
  mMessage = (ListView) findViewById(R.id.message);

  mRecMessage = new ReceiverMessage();
  mRecMessage.setOnReceiverListener(new RecListener());
  mRecMessage.run();

  mSendMesage = new SendMessage();
  mSendMesage.setOnSendListener(new SendListener());

  mAdapter = new MessagesAdapter(this, mData);
  mMessage.setAdapter(mAdapter);
 }

 public void send(View view) {
  String[] content = mEdit.getText().toString().trim().split(":");
  mSendMesage.send(mUserName, content[0], content[1]);
 }

 private class RecListener implements ReceiverMessage.OnReceiverListener {
  @Override
  public void onReceiver(String user, String msg) {
   Map<String, String> temp = new HashMap<String, String>();
   temp.put("user", user);
   temp.put("msg", msg);
   temp.put("pos", "right");
   mData.add(temp);
   mAdapter.notifyDataSetChanged();
  }
 }

 private class SendListener implements SendMessage.OnSendListener {
  @Override
  public void onSend(String[] msg) {
   Map<String, String> temp = new HashMap<String, String>();
   temp.put("user", "我");
   temp.put("msg", msg[1]);
   temp.put("pos", "left");
   mData.add(temp);
   mAdapter.notifyDataSetChanged();
  }
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  if(R.id.logout == item.getItemId()) {
   Logout logout = new Logout();
   logout.setOnLogoutListener(new Logout.OnLogoutListener() {
    @Override
    public void onLogout(boolean success) {
     if(success) {
      Toast.makeText(Chat.this, "注销成功", Toast.LENGTH_SHORT).show();
      finish();
     }else {
      Toast.makeText(Chat.this, "注销失败", Toast.LENGTH_SHORT).show();
     }
    }
   });

   logout.logout(mUserName);
  }

  return super.onOptionsItemSelected(item);
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  getMenuInflater().inflate(R.menu.main, menu);
  return super.onCreateOptionsMenu(menu);
 }
}

6. 发送消息    

public class SendMessage {
 private OnSendListener mListener;

 public void setOnSendListener(OnSendListener listener) {
  mListener = listener;
 }

 private Handler mHandler = new Handler() {
  public void handleMessage(Message msg) {
   mListener.onSend((String[]) msg.obj);
  };
 };

 // send:from:to:message
 public void send(final String from , final String to, final String msg) {
  new Thread(new Runnable() {
   @Override
   public void run() {
    Socket socket = null;
    try {
     socket = new Socket();
     socket.connect(new InetSocketAddress("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter(socket.getOutputStream());
     writer.println("send:" + from + ":" + to + ":" + msg);
     writer.flush();

     Message message = mHandler.obtainMessage(
       Constant.SUCCESS, new String[] {to, msg});

     message.sendToTarget();
    } catch(Exception e) {
    } finally {
     try {
      socket.close();
     } catch (IOException e) {
      e.printStackTrace();
     }
    }
   }
  }).start();
 }

 public interface OnSendListener {
  public void onSend(String[] msg);
 }
}

7. 接收消息，死循环，但阻塞，没啥问题    

public class ReceiverMessage {
 private OnReceiverListener mListener;
 public void setOnReceiverListener(OnReceiverListener listener) {
  mListener = listener;
 }

 private Handler mHandler = new Handler() {
  public void handleMessage(Message msg) {
   String[] cmds = (String[]) msg.obj;
   mListener.onReceiver(cmds[0], cmds[1]);
  };
 };

 public void run() {
  new Thread(new Runnable() {
   @Override
   public void run() {
    try {
     Socket socket = PConnection.socket;
     while(true) {
      System.out.println("wait for message...");
      BufferedReader reader = new BufferedReader(
        new InputStreamReader(socket.getInputStream()));
      String line = reader.readLine();

      if(line.startsWith("rec")) {
       //rec:fromuser:touser:message
       String[] cmds = line.split(":");
       System.out.println(cmds[0] + ":" + cmds[1] + ":" + cmds[2] + ":" + cmds[3]);
       Message msg = mHandler.obtainMessage(Constant.SUCCESS, new String[] {cmds[1], cmds[3]});
       msg.sendToTarget();
      }
     }
    } catch (Exception e) {
     e.printStackTrace();
    }
   }
  }).start();
 }

 public interface OnReceiverListener {
  public void onReceiver(String user, String msg);
 }
}

8. 注销登录    

public class Logout {
 public OnLogoutListener mListener;

 public void setOnLogoutListener(OnLogoutListener listner) {
  mListener = listner;
 }

 private Handler mHandler = new Handler() {
  public void handleMessage(Message msg) {
   if(Constant.SUCCESS == msg.what) {
    mListener.onLogout(true);
   }else {
    mListener.onLogout(false);
   }
  };
 };

 public void logout(final String user) {
  new Thread(new Runnable() {
   @Override
   public void run() {
    try {
     Socket socket = new Socket();
     socket.connect(new InetSocketAddress("192.168.100.100", 8888), 4000);
     PrintWriter writer = new PrintWriter(socket.getOutputStream());
     writer.println("logout:" + user);
     writer.flush();

     BufferedReader reader = new BufferedReader(
       new InputStreamReader(socket.getInputStream()));

     if("success".equals(reader.readLine())) {
      PConnection.socket = null;
      mHandler.sendEmptyMessage(Constant.SUCCESS);
     }else {
      mHandler.sendEmptyMessage(Constant.FAILED);
     }
    } catch (Exception e) {
     e.printStackTrace();
    }
   }
  }).start();
 }

 public interface OnLogoutListener {
  public void onLogout(boolean success);
 }
}

9. 存放登录后的socket，在发送消息和接收消息时使用该socket    

public class PConnection {
 public static Socket socket;
}

希望本文所述对大家学习有所帮助。