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因此，我编写了自己的AsyncTask类，像本地运行在ThreadPoolExecutor上的系统。一切都很好，直到我决定实施事情的进展。该进度与AsyncTask非常相似，在UI线程上调用onProgressUpdate函数。我遇到的问题是，无论何时在onProgressUpdate中存在System.out或Log.x行，它都会无限期地挂起，没有任何错误或警告。代码如下：Android AsyncTask进度更新挂起
public abstract class Task<A, B> {
private static final Executor EXECUTOR = getExecutor();
private static final int DEFAULT_PRIORITY = Thread.MIN_PRIORITY;
private static final int DEFAULT_PROGRESS_INCREMENT = 1;
private static final Executor getExecutor() {
ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newCachedThreadPool();
executor.setCorePoolSize(1);
executor.allowCoreThreadTimeOut(false);
// TODO set rejection handler
//executor.setRejectedExecutionHandler(new Handler());
// TODO set thread factory
executor.prestartCoreThread();
return executor;
}
public static class ExecutionListener<B> {
public void onPreExecute() {
Log.i("TASK", "Pre - Thread: " + Thread.currentThread().getId());
}
public void onPostExecute(B output) {
Log.i("TASK", "Post - Thread: " + Thread.currentThread().getId() + " - Output: " + output);
}
public void onProgressUpdate(int progress) {
Log.d("TASK", "Hello");
}
}
private Handler handler;
private ExecutionListener<B> executionListener;
private volatile int progress = 0;
private AtomicBoolean progressPublished = new AtomicBoolean(true);
private B output;
public Task() {
this.handler = new Handler();
this.executionListener = new ExecutionListener();
}
public void setExecutionListener(ExecutionListener executionListener) {
if(executionListener == null) {
this.executionListener = new ExecutionListener();
}
else {
this.executionListener = executionListener;
}
}
protected void updateProgress(int progressMade) {
Log.d("TASK", "Test");
progress += progressMade;
if(progressPublished.compareAndSet(true, false)) {
if(!handler.post(new Runnable() {
@Override
public void run() {
Log.d("TASK", new Integer(progress).toString() + " - a");
executionListener.onProgressUpdate(progress);
// Hangs below
progressPublished.lazySet(true);
Log.d("TASK", new Integer(progress).toString() + " - b");
}
})) {
Log.d("TASK", "Failed to post");
}
}
}
protected void updateProgress() {
updateProgress(DEFAULT_PROGRESS_INCREMENT);
}
protected abstract B doTask(A input);
public void execute(final A input, final int priority) {
EXECUTOR.execute(new Runnable() {
@Override
public void run() {
Thread.currentThread().setPriority(priority);
handler.post(new Runnable() {
@Override
public void run() {
executionListener.onPreExecute();
}
});
output = doTask(input);
if(!handler.post(new Runnable() {
@Override
public void run() {
Log.d("TASK", "Done");
executionListener.onPostExecute(output);
}
})) {
Log.d("TASK", "Failed to post post");
}
}
});
}
public void execute(final A input) {
execute(input, DEFAULT_PRIORITY);
}
}
的ExecutionListener只是覆盖到很像的AsyncTask的方法做同样的UI运行方法的类。该代码使用Runnable对象执行doTask方法，并将更新/结果发送到ExecutionListener中的相应方法。
Thread.currentThread()零件只是为了确保事物在我希望它们的线程上运行。这个问题只在运行一个经常调用的任务时才会显示出来。updateProgress() - 我试图在onProgressUpdate()方法中放置一个线程睡眠，并且这似乎很好解决问题，但显然这不是一个好的解决方案。
它也似乎只有Log.x/System.out有问题 - 我不知道他们中的任何一个的调用频率是否会导致此类问题。我对这个进度特性和记录感到不知所措，所以任何建议都将不胜感激 - 我也发现这很难解释，所以请问你是否需要我澄清任何事情！