1、获得网络信息
首先在AndroidManifest.xml中加入权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
Code代码如下：
public class MainActivity extends Activity {
TextView netWorkTextView;
ConnectivityManager cManager;
NetworkInfo networkInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
netWorkTextView = (TextView)findViewById(R.id.networkInfo);
cManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
}
@Override
protected void onStart()
{
super.onStart();
networkInfo = cManager.getActiveNetworkInfo();
netWorkTextView.setText(networkInfo.toString());
}
}
显示入下图：代表的意思，采用WIFI连接，其它不解释。
2 .Socket的网络通信
1）服务端： 新建Android工程SocketServerDemo。
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this,SocketService.class));
}
}
SocketService类
public class SocketService extends Service{
Thread mServiceThread;
Socket client;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate()
{
super.onCreate();
mServiceThread = new Thread(new SocketServerThread());
}
public class SocketServerThread extends Thread {
private static final int PORT = 8801;
private SocketServerThread() {
}
@Override
public void run() {
// TODO Auto-generated method stub
try {
ServerSocket serverSocket = new ServerSocket(PORT);
while(true)
{
System.out.println("begin client connected");
client = serverSocket.accept();
System.out.println("client connected");
BufferedReader reader = new BufferedReader(
new InputStreamReader(client.getInputStream()));
System.out.println("read from client:");
String textLine = reader.readLine();
if (textLine.equalsIgnoreCase("EXIT")) {
System.out.println("EXIT invoed, closing client");
break;
}
System.out.println(textLine);
PrintWriter writer = new PrintWriter(
new BufferedWriter(new OutputStreamWriter(client.getOutputStream())));
writer.println("ECHO from server: " + textLine);
writer.flush();
writer.close();
reader.close();
}
} catch (IOException e) {
// TODO: handle exception
System.err.println(e);
}
}
}
}
2）客户端：新建Android工程SocketClientDemo
public class MainActivity extends Activity {
private static final String SERVERIP = "192.168.1.100"; //自己电脑的IP
private static final int SERVERPORT = 8801;
TextView mMsgRev;
EditText mMsgEdit;
Button mMsgSendBtn;
String mSendMsg;
String mReceivedMsg;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mMsgRev = (TextView) findViewById(R.id.receive_msg);
mMsgEdit = (EditText) findViewById(R.id.edit_msg);
mMsgSendBtn = (Button) findViewById(R.id.send_msg);
mMsgSendBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Socket socket = null;
mSendMsg = mMsgEdit.getText().toString();
try {
socket = new Socket(SERVERIP, SERVERPORT);
PrintWriter writer = new PrintWriter(
new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())));
writer.println(mSendMsg);
writer.flush();
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
mReceivedMsg = reader.readLine();
if (mReceivedMsg != null) {
mMsgRev.setText(mReceivedMsg);
}
else {
mMsgRev.setText("receive data error");
}
writer.close();
reader.close();
socket.close();
} catch (UnknownHostException e) {
// TODO: handle exception
Log.i("Error", e.getMessage());
}
catch (IOException e) {
// TODO: handle exception
Log.i("Error", e.getMessage());
}
}
});
}
}
其中客户端跑在我的平板上，服务端跑在我的手机上。然后再服务端的文本框中输入文本，点击Send按钮，最后会收到信息。
注意：两个程序的端口号8801都是相同的，客户端的IP地址是我的电脑IP地址，两个程序都要有权限
<uses-permission android:name="android.permission.INTERNET" ></uses-permission>