我正在尝试对 Android 服务器/客户端软件集进行故障排除，该软件似乎正在记录大量包含“套接字设置捕获 IO 异常”的 logcat 消息，因此我猜测它处于循环中。 为了进行故障排除，我将服务器和客户端安装在同一物理设备上，并遇到了相同的问题。 阅读代码我无法弄清楚为什么会这样，我添加了从//STACKEXCHANGE 开始的注释，我在其中看到了三个 logcat 消息被记录。谁能给我一些指示，我不是一个java程序员，只是一个热心的技术人员试图让这个工作......
logcat 按以下顺序记录消息
ControlLoop 启动 套接字设置捕获 IOException 套接字已建立 套接字关闭 控制循环结束
这是客户端软件的代码。
package com.jrbowling.robotclient;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.util.Log;
import android.widget.ToggleButton;
import android.widget.SeekBar;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.Toast;
import android.widget.EditText;
import android.widget.ImageView;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.Window;
import android.view.WindowManager;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.net.SocketTimeoutException;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiManager.WifiLock;
import android.net.wifi.WifiInfo;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.view.View.OnTouchListener;
import android.view.MotionEvent;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.net.SocketTimeoutException;
import android.app.AlertDialog;
import android.content.DialogInterface;
import java.net.SocketAddress;
import java.net.InetSocketAddress;
import android.os.Handler;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
public class MainActivity extends Activity {
Thread vidThread = null;
Thread clientThread = null;
private Socket s;
private static final String TAG = "RobotClient";
//private ToggleButton tb;
private ImageButton forward_button;
private ImageButton reverse_button;
private ImageButton right_button;
private ImageButton left_button;
private SeekBar throttle;
private ImageView imageWindow;
private ImageView connectedLED;
private ImageView signalStrengthIndicator;
private Boolean stayConnected = false;
String vidURL = "";
private String robotIP = "";
String direction = "stop";
Integer speed = 100;
Boolean robotEnabled = true;
Boolean robotConnected = false;
private Handler GUIUpdateHandler = new Handler();
private Integer signalStrength = 0;
private SharedPreferences pref;
private long timeLastPress = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//set fullscreeen, black
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
setActivityBackgroundColor(0xff000000);
Log.i(TAG, "Robot client started");
initGUIComponents();
//get Robot IP from user, kick off threads and GUI updater
showIPAlert();
}
@Override
protected void onDestroy() {
Log.d(TAG,"onDestroy() called");
stayConnected = false;
socketCleanup();
super.onDestroy();
}
//@Override
//protected void onPause() {
// Log.d(TAG,"onPause() called");
// stayConnected = false;
// socketCleanup();
// super.onDestroy();
// }
@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;
}
@Override
public void onBackPressed() {
//on back button, prompt user to press it again within 2 seconds to exit
Toast onBackPressedToast = Toast.makeText(this, "Press again within 2 seconds to confirm exit", Toast.LENGTH_SHORT);
long currentTime = System.currentTimeMillis();
if (currentTime - timeLastPress > 2000) {
onBackPressedToast.show();
timeLastPress = currentTime;
} else {
onBackPressedToast.cancel();
super.onBackPressed();
}
}
private void initGUIComponents()
{
imageWindow = (ImageView) findViewById(R.id.imageView1);
connectedLED = (ImageView) findViewById(R.id.imageViewConnectStatus);
signalStrengthIndicator = (ImageView) findViewById(R.id.ImageViewSignalStrength);
forward_button = (ImageButton) findViewById(R.id.forwardButton);
reverse_button = (ImageButton) findViewById(R.id.reverseButton);
right_button = (ImageButton) findViewById(R.id.rightButton);
left_button = (ImageButton) findViewById(R.id.leftButton);
throttle = (SeekBar)findViewById(R.id.throttleSeekbar);
throttle.setProgress(75);
forward_button.setOnTouchListener(forwardButtonListener);
reverse_button.setOnTouchListener(reverseButtonListener);
right_button.setOnTouchListener(rightButtonListener);
left_button.setOnTouchListener(leftButtonListener);
}
private void showIPAlert() {
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.setTitle("Please enter robot IP address");
alert.setMessage("Example: 192.168.1.100");
final EditText input = new EditText(this);
alert.setView(input);
input.setText(loadIP().toString());
alert.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
robotIP = input.getText().toString();
Log.i(TAG, "User entered IP " + robotIP);
saveIP(robotIP);
//Handler launches GUIUpdater every 1000 ms. Launch when user clicks ok.
updateGUI();
//start network thread
stayConnected = true;
//launch network thread
clientThread = new Thread(new ClientThread());
clientThread.start();
vidURL = "http://"+robotIP+":8082/shot.jpg";
vidLoop();
}
});
alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
appExit();
}
});
alert.show();
}
private void appExit()
{
Log.i(TAG, "Exit requested by user");
this.finish();
}
private OnTouchListener forwardButtonListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
switch ( event.getAction() ) {
case MotionEvent.ACTION_DOWN:
//setActivityBackgroundColor(0xffff0000);
direction = "forward";
break;
case MotionEvent.ACTION_UP:
//setActivityBackgroundColor(0xff000000);
direction = "stop";
break;
}
return false;
}
};
private OnTouchListener reverseButtonListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
switch ( event.getAction() ) {
case MotionEvent.ACTION_DOWN:
//setActivityBackgroundColor(0xffff0000);
direction = "reverse";
break;
case MotionEvent.ACTION_UP:
//setActivityBackgroundColor(0xff000000);
direction = "stop";
break;
}
return false;
}
};
private OnTouchListener rightButtonListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
switch ( event.getAction() ) {
case MotionEvent.ACTION_DOWN:
//setActivityBackgroundColor(0xffff0000);
direction = "rotateRight";
break;
case MotionEvent.ACTION_UP:
//setActivityBackgroundColor(0xff000000);
direction = "stop";
break;
}
return false;
}
};
private OnTouchListener leftButtonListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
switch ( event.getAction() ) {
case MotionEvent.ACTION_DOWN:
//setActivityBackgroundColor(0xffff0000);
direction = "rotateLeft";
break;
case MotionEvent.ACTION_UP:
//setActivityBackgroundColor(0xff000000);
direction = "stop";
break;
}
return false;
}
};
//save and retrieve IP address using the shared preferences framework
private void saveIP(String IP)
{
//set up shared preferences editor
pref = getApplicationContext().getSharedPreferences("RobotClient", 0);
Editor editor = pref.edit();
editor.putString("robotIP", IP);
editor.commit();
}
private String loadIP()
{
String result;
pref = getApplicationContext().getSharedPreferences("RobotClient", 0);
Editor editor = pref.edit();
result = pref.getString("robotIP", "10.20.30.43");
return result;
}
private void setActivityBackgroundColor(int color) {
//0xff00ff00 first two are transparency, then rgb
View view = this.getWindow().getDecorView();
view.setBackgroundColor(color);
}
//periodically run updater to set connection status and wifi signal strength from robot
private void updateGUI()
{
GUIUpdateHandler.postDelayed(GUIUpdater, 1000);
}
private Runnable GUIUpdater = new Runnable(){
public void run() {
//Periodically update GUI elements from sensor and other data
Log.d(TAG,"Connected is: " + robotConnected.toString());
//update connection status
if (robotConnected)
{
connectedLED.setImageResource(R.drawable.led_green);
//update the wifi signal strength indicator
if ((signalStrength == 5) || (signalStrength==4))
signalStrengthIndicator.setImageResource(R.drawable.wifi4);
if (signalStrength == 3)
signalStrengthIndicator.setImageResource(R.drawable.wifi3);
if (signalStrength == 2)
signalStrengthIndicator.setImageResource(R.drawable.wifi2);
if (signalStrength == 1)
signalStrengthIndicator.setImageResource(R.drawable.wifi1);
if (signalStrength == 0)
signalStrengthIndicator.setImageResource(R.drawable.wifi0);
}
else
{
connectedLED.setImageResource(R.drawable.led_red);
signalStrengthIndicator.setImageResource(R.drawable.wifi0);
}
if (stayConnected)
updateGUI();
}
};
public void setConnected(boolean connected) {
robotConnected = connected;
}
public void socketCleanup()
{
try {
Log.d("clientThread","Socket Closing");
if (s != null)
s.close();
setConnected(false);
} catch (IOException e) {
Log.d(TAG, "Client comm thread got IOException in socketCleanup().");
}
}
private void vidLoop() //started from GUI alert, then kept going with call me from asynctask
{
if (stayConnected)
{
ImageDownloader id = new ImageDownloader();
id.execute(vidURL);
}
}
//this very useful chunk of code is from http://www.peachpit.com/articles/article.aspx?p=1823692&seqNum=3
private class ImageDownloader extends AsyncTask<String, Integer, Bitmap>{
protected void onPreExecute(){
}
@Override
protected Bitmap doInBackground(String... params) {
//TODO Auto-generated method stub
try{
URL url = new URL(params[0]);
HttpURLConnection httpCon =
(HttpURLConnection)url.openConnection();
if(httpCon.getResponseCode() != 200)
throw new Exception("Failed to connect");
InputStream is = httpCon.getInputStream();
return BitmapFactory.decodeStream(is);
}catch(Exception e){
Log.e("Image","Failed to load image",e);
}
return null;
}
protected void onProgressUpdate(Integer... params){
//Update a progress bar here, or ignore it, it's up to you
}
protected void onPostExecute(Bitmap img){
ImageView iv = (ImageView)findViewById(R.id.imageView1);
if(iv!=null && img !=null){
iv.setImageBitmap(img);
//start next image grab
vidLoop();
}
}
protected void onCancelled(){
}
}
class ClientThread implements Runnable {
private static final int SERVERPORT = 8082;
public void run() {
Log.d("clientThread","clientThread started");
setConnected(false);
while ((!Thread.currentThread().isInterrupted()) && stayConnected)
{
controlLoop();
}
//user requested disconnect
Log.d("clientThread","clientThread ending");
}
void controlLoop()
{
BufferedReader s_input = null;
PrintWriter s_output = null;
String inputString = null;
String outputString = null;
Boolean continueLoop = true;
Log.d("clientThread","controlLoop starting");
//protocol:
//Java boolean: enabled or disabled
//Directions: stop, rotateRight, rotateLeft, forward, reverse
//Client sends: robotEnabled,direction,servoPanValue
//Server replies: sensor1,sensor2...
continueLoop = true;
try {
InetAddress serverAddr = InetAddress.getByName(robotIP);
Socket s = new Socket();
//int timeout = 2000; // DEFAULT milliseconds
int timeout = 6000; // milliseconds
SocketAddress sockaddr = new InetSocketAddress(serverAddr, SERVERPORT);
s.connect(sockaddr, timeout);
s_input = new BufferedReader(new InputStreamReader(s.getInputStream()));
s_output = new PrintWriter(s.getOutputStream(), true);
} catch (UnknownHostException e1) {
e1.printStackTrace();
Log.d("clientThread","Got invalid IP string in client thread");
continueLoop = false;
} catch (IOException e) {
Log.d("clientThread","Socket setup caught IOexception");
continueLoop = false;
//STACKEXCHANGE - THIS SEEMS TO BE WHERE THE CODE REPEATEDLY LOOPS AROUND TRYING TO CONNECT**********************************************************************************************
}
//STACKEXCHANGE - Loop starts below again and then logging "controlloop ending"
Log.d("clientThread","Socket Established");
setConnected(true);
try {
while ((stayConnected) && (continueLoop)) {
speed = throttle.getProgress();
if (stayConnected)
outputString = robotEnabled.toString() + "," + direction.toString() + "," + speed.toString();
else
outputString = "quit";
s_output.println(outputString);
if (!s_output.checkError())
{
inputString = s_input.readLine();
if (inputString == null)
{
continueLoop = false;
Log.d("clientThread","Unexpected disconnection.");
}
else
{
Log.d("clientThread","Client got: " + inputString.toString());
//parse returned string, which is just an integer containing the signal strength
try {
signalStrength = Integer.parseInt(inputString);
} catch(NumberFormatException nfe) {
Log.d(TAG,"Got invalid signal strength from client");
}
}
}
else
{
//printwriter.checkError returned true, something bad happened network-wise
continueLoop = false;
Log.d("clientThread","Printwriter.checkError() returned true, likely network problem");
}
}
socketCleanup();
Log.d("clientThread","controlLoop ending");
//STACKEXCHANGE - This is also logged in the catlog at the end of repetitive loop
} catch (IOException e) {
//this happens if the connection times out.
Log.d("clientThread", "Client comm thread got IOException in control loop.");
socketCleanup();
}
}//end control loop
} //end client thread
}
最佳答案
这是因为你没有修改stayConnected。 你不断地打电话
while ((!Thread.currentThread().isInterrupted()) && stayConnected)
{
controlLoop();
}
并且每次调用都会出现异常。仅将 continueLoop 修改为 false。您应该在这种情况下中断您的 while 或根据您的预期行为中断您的线程；或者其他一些方法也可以。
关于java - 为什么这段代码会以 "Socket setup caught IOexception"循环，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28705717/