在我之前关于 HtmlUnit 的问题 中，跳过 HTML 单元中的特定 Javascript 执行 和 使用 HtmlUnit 获取页面源： URL 卡住了
我曾提到 URL 卡住了。我还发现它被卡住了，因为 HtmlUnit 库中的一种方法（解析）没有退出执行。
我对此做了进一步的工作。如果需要超过指定的超时秒数才能完成，我编写了代码以退出该方法。
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import com.gargoylesoftware.htmlunit.BrowserVersion;
import com.gargoylesoftware.htmlunit.FailingHttpStatusCodeException;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
public class HandleHtmlUnitTimeout {
public static void main(String[] args) throws FailingHttpStatusCodeException, MalformedURLException, IOException, InterruptedException, TimeoutException
{
Date start = new Date();
String url = "http://ericaweiner.com/collections/";
doWorkWithTimeout(url, 60);
}
public static void doWorkWithTimeout(final String url, long timeoutSecs) throws InterruptedException, TimeoutException {
//maintains a thread for executing the doWork method
ExecutorService executor = Executors.newFixedThreadPool(1);
//logger.info("Starting method with "+timeoutSecs+" seconds as timeout");
//set the executor thread working
final Future<?> future = executor.submit(new Runnable() {
public void run()
{
try
{
getPageSource(url);
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
});
//check the outcome of the executor thread and limit the time allowed for it to complete
try {
future.get(timeoutSecs, TimeUnit.SECONDS);
} catch (Exception e) {
//ExecutionException: deliverer threw exception
//TimeoutException: didn't complete within downloadTimeoutSecs
//InterruptedException: the executor thread was interrupted
//interrupts the worker thread if necessary
future.cancel(true);
//logger.warn("encountered problem while doing some work", e);
throw new TimeoutException();
}finally{
executor.shutdownNow();
}
}
public static void getPageSource(String productPageUrl)
{
try {
if(productPageUrl == null)
{
productPageUrl = "http://ericaweiner.com/collections/";
}
WebClient wb = new WebClient(BrowserVersion.FIREFOX_3_6);
wb.getOptions().setTimeout(120000);
wb.getOptions().setJavaScriptEnabled(true);
wb.getOptions().setThrowExceptionOnScriptError(true);
wb.getOptions().setThrowExceptionOnFailingStatusCode(false);
HtmlPage page = wb.getPage(productPageUrl);
wb.waitForBackgroundJavaScript(4000);
wb.closeAllWindows();
}
catch (FailingHttpStatusCodeException e)
{
e.printStackTrace();
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
这段代码确实来自 doWorkWithTimeout(url, 60); 方法。但这并没有终止。
当我尝试使用以下代码调用类似的实现时：
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import org.apache.log4j.Logger;
public class HandleScraperTimeOut {
private static Logger logger = Logger.getLogger(HandleScraperTimeOut .class);
public void doWork() throws InterruptedException {
logger.info(new Date()+ "Starting worker method ");
Thread.sleep(20000);
logger.info(new Date()+ "Ending worker method ");
//perform some long running task here...
}
public void doWorkWithTimeout(int timeoutSecs) {
//maintains a thread for executing the doWork method
ExecutorService executor = Executors.newFixedThreadPool(1);
logger.info("Starting method with "+timeoutSecs+" seconds as timeout");
//set the executor thread working
final Future<?> future = executor.submit(new Runnable() {
public void run()
{
try
{
doWork();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
});
//check the outcome of the executor thread and limit the time allowed for it to complete
try {
future.get(timeoutSecs, TimeUnit.SECONDS);
} catch (Exception e) {
//ExecutionException: deliverer threw exception
//TimeoutException: didn't complete within downloadTimeoutSecs
//InterruptedException: the executor thread was interrupted
//interrupts the worker thread if necessary
future.cancel(true);
logger.warn("encountered problem while doing some work", e);
}
executor.shutdown();
}
public static void main(String a[])
{
HandleScraperTimeOut hcto = new HandleScraperTimeOut ();
hcto.doWorkWithTimeout(30);
}
}
如果有人可以看看并告诉我问题是什么，那将非常有帮助。
有关问题的更多详细信息，您可以查看在 HTML 单元中跳过特定的 Javascript 执行 并 使用 HtmlUnit 获取页面源：URL 卡住了
更新 1 奇怪的是：future.cancel(true); 在这两种情况下都返回 TRUE。我的预期是：
- 使用 HtmlUnit 它应该返回 FALSE，因为进程仍然挂起。
- 使用正常的 Thread.sleep(); 它应该返回 TRUE，因为该过程已成功取消。
更新 2
它只与http://ericaweiner.com/collections/URL 挂起。如果我给任何其他 URL 即http://www.google.com, http://www.yahoo.com，它不会手。在这些情况下，它会抛出 IntruptedException 并退出进程。
似乎http://ericaweiner.com/collections/页面源具有某些导致问题的元素。