在上一篇文章中介紹了WiFi的搜索和連接,如果你還沒閱讀過,建議先閱讀上一篇Android WiFi開發教程(二)——WiFi的搜索和連接。本篇接着簡單介紹手機上如何通過WiFi熱點進行數據傳輸。
跟藍牙通訊一樣,WiFi熱點數據傳輸也是要運用到Socket。這裏我創建了兩個線程ConnectThread和ListenerThread,分別去處理數據傳輸和監聽連接。
ConnectThread
**
* 連接線程
* Created by 坤 on 2016/9/7.
*/
public class ConnectThread extends Thread{
private final Socket socket;
private Handler handler;
private InputStream inputStream;
private OutputStream outputStream;
public ConnectThread(Socket socket, Handler handler){
setName("ConnectThread");
this.socket = socket;
this.handler = handler;
}
@Override
public void run() {
if(socket==null){
return;
}
handler.sendEmptyMessage(MainActivity.DEVICE_CONNECTED);
try {
//獲取數據流
inputStream = socket.getInputStream();
outputStream = socket.getOutputStream();
byte[] buffer = new byte[1024];
int bytes;
while (true){
//讀取數據
bytes = inputStream.read(buffer);
if (bytes > 0) {
final byte[] data = new byte[bytes];
System.arraycopy(buffer, 0, data, 0, bytes);
Message message = Message.obtain();
message.what = MainActivity.GET_MSG;
Bundle bundle = new Bundle();
bundle.putString("MSG",new String(data));
message.setData(bundle);
handler.sendMessage(message);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 發送數據
*/
public void sendData(String msg){
if(outputStream!=null){
try {
outputStream.write(msg.getBytes());
Message message = Message.obtain();
message.what = MainActivity.SEND_MSG_SUCCSEE;
Bundle bundle = new Bundle();
bundle.putString("MSG",new String(msg));
message.setData(bundle);
handler.sendMessage(message);
} catch (IOException e) {
e.printStackTrace();
Message message = Message.obtain();
message.what = MainActivity.SEND_MSG_ERROR;
Bundle bundle = new Bundle();
bundle.putString("MSG",new String(msg));
message.setData(bundle);
handler.sendMessage(message);
}
}
}
}
在ConnectThread的構造中,傳入了Socket和Handler。Socket用來獲取數據以及發送數據,Handler用來更新UI了。在run方法中,我們從Socket中獲取到了輸入流和輸出流,然後循環地讀取InputStream的數據,當讀取到數據時,則通過Handler將數據更新到UI上。在sendData方法中主要是通過OutputStream寫入數據,然後將寫入結果通過Handler更新到UI上。
ListenerThread
/**
* 監聽線程
* Created by 坤 on 2016/9/7.
*/
public class ListenerThread extends Thread{
private ServerSocket serverSocket = null;
private Handler handler;
private int port;
private Socket socket;
public ListenerThread(int port, Handler handler){
setName("ListenerThread");
this.port = port;
this.handler = handler;
try {
serverSocket=new ServerSocket(port);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
while (true){
try {
//阻塞,等待設備連接
socket = serverSocket.accept();
Message message = Message.obtain();
message.what = MainActivity.DEVICE_CONNECTING;
handler.sendMessage(message);
} catch (IOException e) {
e.printStackTrace();
}
}
}
public Socket getSocket() {
return socket;
}
}
監聽線程處理的邏輯就比較簡單,通過端口號獲取ServerSocket後調用accept()阻塞線程,直到有設備連接上後就通過Handler更新UI。這裏需要注意的是連接上的設備的端口號必須與這裏的端口號相同。接着我們看看Hander獲取到消息後做了哪些處理。
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case DEVICE_CONNECTING:
connectThread = new ConnectThread(listenerThread.getSocket(),handler);
connectThread.start();
break;
... ...
}
}
};
可以看到Handler獲取到數據後,通過listenerThread.getSocket()將獲取到Socket和handler一同創建了ConnectThread實例。
接下來就是用這兩個線程來處理數據傳輸了。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
... ...
listenerThread = new ListenerThread(PORT, handler);
listenerThread.start();
}
在onCreate中我們創建ListenerThread並啓動它,讓它監聽是否有設備連接上來。當然這裏需要先開啓WiFi熱點後纔會有設備連接上來。這是開啓熱點並等待設備連接的情況。當然我們也可以主動去連接其他開啓着熱點的設備。
在監聽WiFi連接情況的廣播接收者中加入下面的代碼
if (info.getState().equals(NetworkInfo.State.CONNECTED)) {
WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final WifiInfo wifiInfo = wifiManager.getConnectionInfo();
text_state.setText("已連接到網絡:" + wifiInfo.getSSID());
if (wifiInfo.getSSID().equals(WIFI_HOTSPOT_SSID)) {
//如果當前連接到的wifi是熱點,則開啓連接線程
new Thread(new Runnable() {
@Override
public void run() {
try {
ArrayList<String> connectedIP = getConnectedIP();
for (String ip : connectedIP) {
if (ip.contains(".")) {
Socket socket = new Socket(ip, PORT);
connectThread = new ConnectThread(socket, handler);
connectThread.start();
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
} else {
...
}
}
這裏本地固定了其他設備WiFi熱點的SSID,如果當前連接的WiFi的SSID跟我們之前保存的SSID一致,則證明我們連上了我們需要的WiFi熱點。然後通過getConnectedIP()獲取WiFi熱點的IP地址,通過這個IP地址和端口號創建一個Socket,然後創建ConnectThread來處理數據傳輸。到這裏我們可以看到,PORT和SSID這兩個數據是需要兩個設備事先協議好的。
最後再看看Handler完整的代碼
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case DEVICE_CONNECTING:
connectThread = new ConnectThread(listenerThread.getSocket(),handler);
connectThread.start();
break;
case DEVICE_CONNECTED:
textview.setText("設備連接成功");
break;
case SEND_MSG_SUCCSEE:
textview.setText("發送消息成功:" + msg.getData().getString("MSG"));
break;
case SEND_MSG_ERROR:
textview.setText("發送消息失敗:" + msg.getData().getString("MSG"));
break;
case GET_MSG:
textview.setText("收到消息:" + msg.getData().getString("MSG"));
break;
}
}
};
至此,WiFi熱點數據傳輸也就介紹完了。如果有什麼疑問,歡迎和本人一起探討。
最後附上源碼地址
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