我想问一些关于android socket的问题。我创建了一个示例应用程序将数据发送到wifly模块。但是,当我从模块接收数据我得到套接字超时异常。没有setSoTimeout
应用冻结到inputStream.read
。这里是我的代码:android socket果冻豆
package com.socket.wiflysocket;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
protected static final String TAG = "WIflySocket";
EditText textOut;
TextView textIn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textOut = (EditText)findViewById(R.id.textout);
Button buttonSend = (Button)findViewById(R.id.send);
textIn = (TextView)findViewById(R.id.textin);
buttonSend.setOnClickListener(buttonSendOnClickListener);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
Button.OnClickListener buttonSendOnClickListener
= new Button.OnClickListener(){
@Override
public void onClick(View arg0) {
ConnectivityManager connMgr = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo == null || networkInfo.isConnected() == false) {
try {
throw new Exception("Network is not connected");
} catch (Exception e) {
e.printStackTrace();
}
}
else {
new SocketThread(textOut.getText().toString()).execute();
textOut.setText("");
}
}};
}
和asynkTask:
package com.socket.wiflysocket;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import android.os.AsyncTask;
import android.util.Log;
public class SocketThread extends AsyncTask<String, Void, String>{
private static final String TAG = "SocketAsyncTask";
private static final int BUFFER_SIZE = 8;
private String textViewIn;
private String output;
private Socket socket = null;
private PrintWriter outputStream;
private InputStreamReader inputStream;
public SocketThread(String paramTextViewIn)
{
this.textViewIn = paramTextViewIn;
}
@Override
protected String doInBackground(String ...views) {
Log.d(TAG, "Execute");
DataOutputStream dataOutputStream = null;
DataInputStream dataInputStream = null;
try {
socket = new Socket("1.2.3.4", 2000);
socket.setSoTimeout(2000);
outputStream = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
inputStream = new InputStreamReader(socket.getInputStream());
if(socket.isConnected()) {
this.sendDataWithString(textViewIn);
output = this.receiveDataFromServer();
}
this.closeSocket();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
finally{
if (socket != null){
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (dataOutputStream != null){
try {
dataOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (dataInputStream != null){
try {
dataInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return output;
}
/*
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
return textViewOut;
}
*/
private void closeSocket() {
if (socket != null) {
if (socket.isConnected()) {
try {
inputStream.close();
outputStream.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void sendDataWithString(String message) {
if (message != null) {
outputStream.write(message);
outputStream.flush();
}
}
private String receiveDataFromServer() {
String message = "";
try {
int charsRead = 0;
char[] buffer = new char[BUFFER_SIZE];
while ((charsRead = inputStream.read(buffer)) != -1) {
message += new String(buffer).substring(0, charsRead);
}
closeSocket();
return message;
} catch (IOException e) {
//TODO work around
return message;
//return "Error receiving response: " + e.getMessage();
}
}
}
许可,我补充如下:
android.permission.INTERNET
; android.permission.ACCESS_NETWORK_STATE
你能否建议我,什么是错的,以及如何解决这个问题。 感谢
'inputStream.read()'阻塞,直到输入数据可用,检测到文件结尾或引发异常。 – mjosh
当调试应用程序我注意到,但如何获得数据结束?在调试模式下,我查看发送数据到wifly终端(teraterm)连接到wifly与串行端口。从wifly发送的数据是'Hello',但是当套接字抛出异常时我得到它。我是套接字编程的新手,不知道如何实现正确。 –