我正在开发一个通过套接字连接到服务器的 android Quiz 应用程序。在客户端（Android 设备）上，我在 while 循环中检查服务器（Java 服务器）给出的答案。连接和答案的接收一切顺利。问题是在我的课堂上检查答案有一个错误。为了提供更多信息，我将在此处包含部分代码：
public void startClient(){
checkValue = new Thread(new Runnable(){
@Override
public void run() {
try
{
final int PORT = 4444;
final String HOST = "192.168.1.118";
Socket SOCK = new Socket(HOST, PORT);
Log.e("success", "You connected to: " + HOST);
quizClient = new QuizClient(SOCK);
//Send the groupname to the list
PrintWriter OUT = new PrintWriter(SOCK.getOutputStream());
OUT.println(groupName);
OUT.flush();
Thread X = new Thread(quizClient);
X.start();
connected = true;
}
catch(Exception X)
{
Log.e("connection error", "Error: ", X);
}
}
});
checkValue.start();
}
public void testvalue(){
Thread thread = new Thread(new Runnable(){
@Override
public void run() {
try {
while(true){
if(message != null && !message.matches("")){
Thread.sleep(1000);
Log.e("receive", message);
buffer = message;
message = "";
Message msg = new Message();
String textTochange = buffer;
msg.obj = textTochange;
mHandler.sendMessage(msg);
Thread.sleep(3000);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
thread.start();
}
Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
String text = (String)msg.obj;
//call setText here
//String[] myStringArray = new String[];
value.clear();
String[] items = text.split(";");
for (String item : items)
{
value.add(item);
Log.e("message", item);
//System.out.println("item = " + item);
}
if(value.get(0).equals("1")){
questionGroup.setVisibility(View.INVISIBLE);
sendAnswer.setVisibility(View.INVISIBLE);
answer.setVisibility(View.INVISIBLE);
question.setText("");
question.setText(value.get(2));
rad1.setText(value.get(3));
rad2.setText(value.get(4));
rad3.setText(value.get(5));
rad4.setText(value.get(6));
questionGroup.setVisibility(View.VISIBLE);
sendAnswer.setVisibility(View.VISIBLE);
} else if (value.get(0).equals("2")){
questionGroup.setVisibility(View.INVISIBLE);
sendAnswer.setVisibility(View.INVISIBLE);
answer.setVisibility(View.INVISIBLE);
question.setText("");
question.setText(value.get(2));
answer.setVisibility(View.VISIBLE);
sendAnswer.setVisibility(View.VISIBLE);
} else
{
questionGroup.setVisibility(View.INVISIBLE);
sendAnswer.setVisibility(View.INVISIBLE);
answer.setVisibility(View.INVISIBLE);
question.setText(text);
}
}
};
@Override
protected void onStop()
{
if (connected == true){
try {
quizClient.DISCONNECT();
} catch (IOException e) {
e.printStackTrace();
}
}
if(checkValue != null)
{
checkValue.interrupt();
}
super.onStop();
closeApplication();
}
所以我创建了这个类的一个新实例（我实际上检查传入的数据流）
public class QuizClient implements Runnable {
//Globals
Socket SOCK;
Scanner INPUT;
Scanner SEND = new Scanner(System.in);
PrintWriter OUT;
public QuizClient(Socket X)
{
this.SOCK = X;
}
public void run()
{
try
{
try
{
INPUT = new Scanner(SOCK.getInputStream());
OUT = new PrintWriter(SOCK.getOutputStream());
OUT.flush();
CheckStream();
}
finally
{
SOCK.close();
}
}
catch(Exception X)
{
Log.e("error", "error: ", X);
}
}
public void DISCONNECT() throws IOException
{
OUT.println("DISCONNECT");
OUT.flush();
SOCK.close();
}
public void CheckStream()
{
while(true)
{
RECEIVE();
}
}
public void RECEIVE()
{
if(INPUT.hasNext())
{
String MESSAGE = INPUT.nextLine();
if(MESSAGE.contains("#?!"))
{
}
else
{
QuizActivity.message = MESSAGE;
Log.e("test", MESSAGE);
}
}
}
public void SEND(String X)
{
OUT.println(X);
OUT.flush();
}
}
所以我认为在下面的课程中这个错误仍然存在：
public void testvalue(){
Thread thread = new Thread(new Runnable(){
@Override
public void run() {
try {
while(true){
if(message != null && !message.matches("")){
Thread.sleep(1000);
Log.e("receive", message);
buffer = message;
message = "";
我在这里做的是创建一个线程并检查“消息”是否不等于 null。消息来自另一个类：
public void RECEIVE()
{
if(INPUT.hasNext())
{
String MESSAGE = INPUT.nextLine();
if(MESSAGE.contains("#?!"))
{
}
else
{
QuizActivity.message = MESSAGE;
现在大多数时候这很好用，但有两个问题。当我离开页面时，它与服务器断开连接（工作）我返回页面并再次连接到服务器，但这次我没有在屏幕上获得任何值（接收正常，但对于另一个原因在我的处理程序中效果不佳）。一段时间后还会得到一个 indexoutofboundexception：
question.setText(value.get(2));
第二个问题在程序运行时出现了一段时间。有时我的界面在正确接收输入时也没有得到值。
所以我的猜测是，我对读取值的线程的解决方案并不是处理它的最佳方法。所以现在我问有更多经验的人，我可以做些什么来使这项工作没有重大问题？您需要知道连接是否有效，并且我在 QuizClient 类中获得了值。所以问题需要在我的主要课程中。
我的 oncreate 课程：
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz);
selectgroep = (Spinner) findViewById(R.id.groepen);
questionGroup = (RadioGroup) findViewById(R.id.QuestionGroup);
sendAnswer = (Button) findViewById(R.id.sendAnswer);
rad1 = (RadioButton) findViewById(R.id.radio0);
rad2 = (RadioButton) findViewById(R.id.radio1);
rad3 = (RadioButton) findViewById(R.id.radio2);
rad4 = (RadioButton) findViewById(R.id.radio3);
answer = (EditText) findViewById(R.id.textanswer);
questionGroup.setVisibility(View.INVISIBLE);
sendAnswer.setVisibility(View.INVISIBLE);
answer.setVisibility(View.INVISIBLE);
try {
connect();
} catch (InterruptedException e) {
e.printStackTrace();
}
//Code na het drukken op de knop
startserver = (Button) findViewById(R.id.startserver);
startserver.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
startClient();
getID();
testvalue();
}
});
sendAnswer.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// Stuur antwoord door en sluit alles af
questionGroup.setVisibility(View.INVISIBLE);
sendAnswer.setVisibility(View.INVISIBLE);
answer.setVisibility(View.INVISIBLE);
answer.setText("");
rad1.setChecked(true);
rad1.setText("");
rad2.setText("");
rad3.setText("");
rad4.setText("");
question.setText("Wachten op server ... ");
}
});
}
提前谢谢你，托马斯·索夫特