【发布时间】：2015-09-03 06:46:22
【问题描述】：
编辑： see here!
我有一个带有 Runnable 的线程，如下所示。它有一个我无法弄清楚的问题：我在线程上调用interrupt() 的一半时间（以停止它）实际上并没有终止（InterruptedException 没有被捕获）。
private class DataRunnable implements Runnable {
@Override
public void run() {
Log.d(TAG, "DataRunnable started");
while (true) {
try {
final String currentTemperature = HeatingSystem.get("currentTemperature");
mView.post(() -> showData(currentTemperature));
} catch (ConnectException e) {
mView.post(() -> showConnectionMessage());
break;
}
try {
Thread.sleep(10);
} catch (InterruptedException e) {
break;
}
}
Log.d(TAG, "DataRunnable terminated");
}
}
问题是HeatingSystem.get(String) 方法进行长时间的网络操作。我猜想在该方法的某个地方，中断标志被重置，但我找不到什么语句会这样做（我没有在该方法所涉及的所有类的引用中找到它，比如HttpURLConnection）。方法如下（不是我写的）。
/**
* Retrieves all data except for weekProgram
* @param attribute_name
* = { "day", "time", "currentTemperature", "dayTemperature",
* "nightTemperature", "weekProgramState" }; Note that
* "weekProgram" has not been included, because it has a more
* complex value than a single value. Therefore the funciton
* getWeekProgram() is implemented which return a WeekProgram
* object that can be easily altered.
*/
public static String get(String attribute_name) throws ConnectException,
IllegalArgumentException {
// If XML File does not contain the specified attribute, than
// throw NotFound or NotFoundArgumentException
// You can retrieve every attribute with a single value. But for the
// WeekProgram you need to call getWeekProgram().
String link = "";
boolean match = false;
String[] valid_names = {"day", "time", "currentTemperature",
"dayTemperature", "nightTemperature", "weekProgramState"};
String[] tag_names = {"current_day", "time", "current_temperature",
"day_temperature", "night_temperature", "week_program_state"};
int i;
for (i = 0; i < valid_names.length; i++) {
if (attribute_name.equalsIgnoreCase(valid_names[i])) {
match = true;
link = HeatingSystem.BASE_ADDRESS + "/" + valid_names[i];
break;
}
}
if (match) {
InputStream in = null;
try {
HttpURLConnection connect = getHttpConnection(link, "GET");
in = connect.getInputStream();
/**
* For Debugging Note that when the input stream is already used
* with this BufferedReader, then after that the XmlPullParser
* can no longer use it. This will cause an error/exception.
*
* BufferedReader inn = new BufferedReader(new
* InputStreamReader(in)); String testLine = ""; while((testLine
* = inn.readLine()) != null) { System.out.println("Line: " +
* testLine); }
*/
// Set up an XML parser.
XmlPullParser parser = Xml.newPullParser();
parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES,
false);
parser.setInput(in, "UTF-8"); // Enter the stream.
parser.nextTag();
parser.require(XmlPullParser.START_TAG, null, tag_names[i]);
int eventType = parser.getEventType();
// Find the single value.
String value = "";
while (eventType != XmlPullParser.END_DOCUMENT) {
if (eventType == XmlPullParser.TEXT) {
value = parser.getText();
break;
}
eventType = parser.next();
}
return value;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
System.out.println("FileNotFound Exception! " + e.getMessage());
// e.printStackTrace();
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (in != null)
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} else {
// return null;
throw new IllegalArgumentException("Invalid Input Argument: \""
+ attribute_name + "\".");
}
return null;
}
/**
* Method for GET and PUT requests
* @param link
* @param type
* @return
* @throws IOException
* @throws MalformedURLException
* @throws UnknownHostException
* @throws FileNotFoundException
*/
private static HttpURLConnection getHttpConnection(String link, String type)
throws IOException, MalformedURLException, UnknownHostException,
FileNotFoundException {
URL url = new URL(link);
HttpURLConnection connect = (HttpURLConnection) url.openConnection();
connect.setReadTimeout(HeatingSystem.TIME_OUT);
connect.setConnectTimeout(HeatingSystem.TIME_OUT);
connect.setRequestProperty("Content-Type", "application/xml");
connect.setRequestMethod(type);
if (type.equalsIgnoreCase("GET")) {
connect.setDoInput(true);
connect.setDoOutput(false);
} else if (type.equalsIgnoreCase("PUT")) {
connect.setDoInput(false);
connect.setDoOutput(true);
}
connect.connect();
return connect;
}
有人知道上述方法中的什么可能导致问题吗？
Thread.sleep() 在进入Thread.sleep() 之前调用interrupt() 时也会抛出InterruptException：Calling Thread.sleep() with *interrupted status* set?。
我检查了中断后是否到达Thread.sleep()，并且到达了。
这就是 DataRunnable 的启动和中断方式（我总是得到“onPause called”日志）：
@Override
public void onResume() {
connect();
super.onResume();
}
@Override
public void onPause() {
Log.d(TAG, "onPause called");
mDataThread.interrupt();
super.onPause();
}
private void connect() {
if (mDataThread != null && mDataThread.isAlive()) {
Log.e(TAG, "mDataThread is alive while it shouldn't!"); // TODO: remove this for production.
}
setVisibleView(mLoading);
mDataThread = new Thread(new DataRunnable());
mDataThread.start();
}
【问题讨论】：
-
只有在调用 Thread.interrupt() 时 Thread.sleep 正在进行时才会引发 InterruptedException。您还需要轮询线程的状态以检查它是否被中断。如果是，请停止进一步的工作。
-
能否包含创建 DataRunnable 的代码以及中断它的部分？
-
@Measuring 已包含部件，感谢迄今为止的反馈。
-
能否多次调用connect？使用相同的 Runnable 生成多个线程？如果线程已经中断，我也错了 Thread.sleep() 不抛出 InterruptedException 。对此感到抱歉。我也不认为在不调试代码的情况下我将无法看到问题。可能值得尝试在 Runnable 代码中添加 System.out.println，以更好地了解耗时长和正在执行的内容。
-
这是我将如何调试它。我可以通过在
DataRunnable的run()方法的最开始添加对Thread.currentThread().interrupt();的调用来中断线程本身。然后我会在整个地方添加一堆System.out.println("line XX - " + Thread.currentThread().isInterrupted());语句。这样，我将缩小中断状态突然变为 false 的范围。希望这可以帮助。 （或者不用打印，只需在观察isInterrupted()值的同时调试每一行）
标签： java android multithreading interrupted-exception