android用socket传递数据给服务器端

[vicky-y]

近期在做一个小项目，想在多个activity之间用同一个socket往服务器端发送数据，因为socket是长连接嘛，如果发送一次关一次这个长连接就没意义了。所以写了一个单独的类用来socket连接。现在问题是：我每次只能连接到服务器并发送一次数据，之后再发送就没反应了。下面贴上代码：
这是用来socket连接服务器的类：

//现在直接在这里设定一个socket只为了连接用，
public class ConnectJudgment {

	public PrintWriter out;
	public String foreMessage="connect before";
	public String laterMessage="connect before";
	public static String Ip="";
	public static int port=50001;
	public static int flag = 0;
	public static Socket socket = null;
	protected ConnectJudgment() {
		connectTask task = new connectTask(this);
		task.execute();
	}
	
	class connectTask extends AsyncTask<String,Integer, String>
	{
		public connectTask(ConnectJudgment connectJudgment) {
			// TODO Auto-generated constructor stub
		}
		@Override
		protected String doInBackground(String... params) {
			try{
				//connect to server with ip&port
				socket = new Socket(InetAddress.getByName(Ip),port);
				flag = 1;
				out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(ConnectJudgment.socket.getOutputStream())), true);
				while(socket.isConnected())
				{
					if(!foreMessage.equals(laterMessage))
					{
						out.println(laterMessage);
						out.flush();
						foreMessage = laterMessage;
					}
				}
				//socket.close();
			}
			catch(Exception e)
			{
				e.printStackTrace();
			}
			return null;
		}
	}
}

这个是调用上面那个socket连接类，并发送数据：

public class Connection_Activity extends ActionBarActivity{
	
	//this is for hide soft keyboard.
	private View connectionLayout;
	//sp is to save data from last time.
	private SharedPreferences sp;
	//show information when you r logging.
	private ProgressDialog progressDialog;
	private EditText Ip;
	private String lastIp = "";
	private Button connectionButton;
	protected PrintWriter out;
	private ConnectJudgment con;
	//if ip is the right rule.
	public boolean isIPAddress(String str)  
	{  
	    Pattern pattern = Pattern.compile( "\\b((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\.((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\.((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\.((?!\\d\\d\\d)\\d+|1\\d\\d|2[0-4]\\d|25[0-5])\\b" );  
	    return pattern.matcher( str ).matches();  
	}  
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.activity_connection);
		//initpush();
		//hide soft keyboard from current view.
		connectionLayout = (View)findViewById(R.id.connectionlayout);
		connectionLayout.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
				imm.hideSoftInputFromWindow(v.getApplicationWindowToken(), 0);
			}
		});
		//initial sp object .default mode is 0.
		sp=this.getSharedPreferences("ip",0);
		//get the control
		Ip = (EditText)findViewById(R.id.IpAddress);
		//to read if there is any data from last time inputing.
		readSharedPreferences();
		connectionButton = (Button)findViewById(R.id.connectButton);
		connectionButton.setOnClickListener(new OnClickListener()
		{
			@Override
			public void onClick(View v) {
				//这里得到了ip地址，是另外的函数不管这个
				if(isIPAddress(ConnectJudgment.Ip))
				{
					saveSharedPreferences();
					con = new ConnectJudgment();
					try
					{
						//show waiting info
						progressDialog = ProgressDialog.show(Connection_Activity.this, "",
								getResources().getString(R.string.waitConnection));
						progressDialog.setCancelable(false);
						new Handler().postDelayed(run,5000);
					}
					catch(Exception e)
					{
						e.printStackTrace();
					}
				}
				else
				{
					Toast.makeText(getApplicationContext(), R.string.IpWrong, Toast.LENGTH_LONG).show();
				}
			}
		});
	}
	//wait a few seconds to jump to another activity.
	Runnable run = new Runnable()
	{
		public void run()
		{
			if(ConnectJudgment.flag == 1)
			{
				//理论上来讲，后台的循环程序一直不断地检测两次message有没有变化
				//而message一旦变了，就进入out.println()发送数据。
				con.laterMessage = "";
				//click the connect button
				Intent intent = new Intent();
				intent.setClass(Connection_Activity.this, SocketTest.class);
				startActivity(intent);
				progressDialog.cancel();
				finish();
			}
			else
			{
				progressDialog.cancel();
				Toast.makeText(getApplicationContext(), R.string.socketWrong, Toast.LENGTH_LONG).show();
			}
		}
	};
	//save data to use it next time.
	private void saveSharedPreferences(){
        SharedPreferences.Editor editor=sp.edit();
        editor.putString("Ip", Ip.getText().toString());
        editor.commit();
    }
	//get data from last inputing.
	private void readSharedPreferences() {
		String IpAddress=sp.getString("Ip", "");
        Ip.setText(IpAddress);
	}
}

紧接着我在另外一个Activity中调用这个socket再传递数据就不行了，

public class SocketTest extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.socket_test);
		String message = "sent failed";
		sendMessage(message);
	}
	public void sendMessage(String mess)
	{
		try {
			PrintWriter out = null;
			if(ConnectJudgment.socket.isConnected())
			{
				out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(ConnectJudgment.socket.getOutputStream())), true);
				out.println(mess);
			}
			out.flush();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

服务器端：

public void run() {
		// TODO Auto-generated method stub
		try
		{
			//get a port from system which is free now.
			serverSocket= new ServerSocket(0);
			Port = serverSocket.getLocalPort();
			while(true)
			{
				//accept the data from client
				Socket client = serverSocket.accept();
				System.out.println("accept");
				try
				{
					//get the data info
					//inputstream to receive data,outputstream to write data
					BufferedReader in = new BufferedReader(new InputStreamReader(
							client.getInputStream()));
					//convert the info into string
					info = in.readLine();
					System.out.println("info: "+info);
					runCommand(info);
					//turn off the source
					in.close();
				}
				catch(Exception e)
				{
					e.printStackTrace();
				}
				finally
				{
					client.close();
				}
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}

服务器端打印了第一次的info： 之后就什么都没有了。

不知道为什么只传递成功了一次数据。

[vicky-y]

怎么没人来回答阿 快来人啊，，，，，大神们

[wangzi_17]

试下ConnectJudgment里的socket设置get/set方法

[vicky-y]

结贴， 不知道为什么没人来回答=。 = 最后自己还是查到了。 之所以每次只能成功发送一次数据有两个原因： 1. 在server端的serverSocket.aceept()放在while(true)的里面，这句话的意思是接受新建立的socket连接并阻塞等待这个socket发送过来数据，而这个只可以接受一次当前socket的数据。 2.因为BufferedReader在一次接收数据完成后就直接关闭。 综上所述，这个服务器这样写是接受不了同一socket用户的多条数据的。 修改：将serverSocket.accept()这句话放在while(true)的前面，然后重新写一个函数用来关闭和socket相关的对象。 而在while(true)接收数据的代码中重新开启一个Thread来执行接收数据的代码，在这个Thread的run函数中加入while(...)循环获取数据的代码。记得不要在这里就关闭BufferedReader对象。 因为这个错误阻塞我两个周，哎，，， 基础知识不懂造成的。

[yfijwan135]

我也遇到同样的问题，楼主有具体demo吗？求赐教，只要服务端的就行，我现在作为服务端，就第一次有效，之后就接收不到了，写在service里的

[大鲸鱼鱼]

加心跳帧啊!!!!!!!!!!!!!!11111