在下面的java应用程序中，我使用TwitterStream使用示例函数收集推文。我需要在用户需要时启动和停止流，但是我得到以下异常：
java.util.concurrent.RejectedExecutionException: Task twitter4j.StatusStreamBase$1@74e75335 rejected from java.util.concurrent.ThreadPoolExecutor@5117b235[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 2]
at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.reject(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.execute(Unknown Source)
at twitter4j.DispatcherImpl.invokeLater(DispatcherImpl.java:58)
at twitter4j.StatusStreamBase.handleNextElement(StatusStreamBase.java:80)
at twitter4j.StatusStreamImpl.next(StatusStreamImpl.java:56)
at twitter4j.TwitterStreamImpl$TwitterStreamConsumer.run(TwitterStreamImpl.java:568)
当用户按下＆＃34; Crawl＆＃34;或者＆＃34;停止抓取＆＃34;，正确调用actionPerformed方法。但是，如果用户按下Crawl然后按下Stop然后再次按Crawl，我会收到上面的错误
我有几个班级，但主要是以下几个班级：
第一个创建接口并与爬虫类通信。
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
public class StackOv extends JFrame implements ActionListener{
private JTextArea usersSaved;
private boolean alreadyCrawling;
private boolean stopReceived;
private Stream stream;
private JButton Crawl;
private JButton stopCrawl;
private Mongo m;
public StackOv(){
this.stopReceived = false;
this.alreadyCrawling = false;
setLayout(new FlowLayout(FlowLayout.CENTER));
Crawl = new JButton("Crawl");
Crawl.setActionCommand("Crawl");
Crawl.addActionListener(this);
stopCrawl = new JButton("Stop Crawling");
stopCrawl.setActionCommand("Stop Crawling");
stopCrawl.addActionListener(this);
m = new Mongo(); //instance of class that uses MongoDB
/*
*
*bla bla bla create the rest of the interface as you wish
*add(button)
*add(button)
*etc...
*/
}
public void setOut(String out){
usersSaved.setText(out);
}
public void setOffAlreadyCrawling(){
this.alreadyCrawling = false;
}
@Override
public void actionPerformed(ActionEvent e){
if(e.getActionCommand().equals("Stop Crawling") && !this.stopReceived){
this.stopReceived = true;
stream.setStop();
}
else if(e.getActionCommand().equals("Crawl") && !alreadyCrawling){
if(stream != null && stream.isAlive()){
stream.interrupt();
}
alreadyCrawling = true;
stream = new Stream(m, this);
//independently of using one of the following two calls, I get the same exception above
stream.execute1();
//stream.start();
this.stopReceived = false;
}
}
public void main(String[] args){
StackOv so = new StackOv();
so.setSize(800, 800);
so.setVisible(true);
}
}
以下类是爬虫类，当stopCrawl为true或者twitterStream已经在超过最大限制时对多个推文进行了采样时关闭了twitterStream。
import java.awt.TextArea;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import twitter4j.FilterQuery;
import twitter4j.StallWarning;
import twitter4j.Status;
import twitter4j.StatusDeletionNotice;
import twitter4j.StatusListener;
import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import twitter4j.TwitterStream;
import twitter4j.TwitterStreamFactory;
public class Stream extends Thread{
private Crawler cr;
private TwitterStream twitterStream;
private int maxTweets;
private int usersSaved;
private Mongo database;
private CreateIndex ci;
private TwitterSearch twitterSearch;
private static boolean stopCrawl;
public Stream(Mongo database, TwitterSearch twitterSearch){
Stream.stopCrawl = false;
this.database = database;
this.cr = new Crawler(database);
this.twitterStream = new TwitterStreamFactory(DefaultConfiguration.getConfiguration()).getInstance();
this.maxTweets = 1000;
ci = new CreateIndex(database);
this.twitterSearch = twitterSearch;
}
public void setStop(){
Stream.stopCrawl = true;
}
public void execute() throws TwitterException {
final List<Status> statuses = new ArrayList<Status>();
StatusListener listener = new StatusListener() {
public void onStatus(Status status) {
statuses.add(status);
System.out.println(statuses.size() + ":" + status.getText());
int usersIndexed = cr.retrieve(status.getUser());
usersSaved = database.countDocuments();
twitterSearch.setOut("usersSaved: "+usersSaved);
if(usersIndexed > maxTweets || Stream.stopCrawl){
//ci.load();
ci.load(); //this call creates my index
twitterSearch.setOut("INDEX CREATED");
System.out.println("shutdown...");
twitterSearch.setOffAlreadyCrawling();
twitterStream.shutdown();
}
}
public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) {
}
public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
}
public void onScrubGeo(long userId, long upToStatusId) {
}
public void onException(Exception ex) {
ex.printStackTrace();
}
@Override
public void onStallWarning(StallWarning arg0) {
// TODO Auto-generated method stub
}
};
twitterStream.addListener(listener);
twitterStream.sample("en");
}
public void execute1(){
try{
this.execute();
}catch(TwitterException e){
e.printStackTrace();
}
}
public void run(){
try {
this.execute();
} catch (TwitterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
答案 0 :(得分：0)
当您的线程关闭/关闭时，它会阻止它“重新启动”，就像其他java IO类一样。换句话说，一旦你关闭它，你就无法再次启动它。我很确定Twitter代码或代码中的某个地方，你的线程正在停止。为防止这种情况发生，以下是可能有效的代码段：http://pastebin.com/APByKuiY 另外，请尝试此堆栈溢出：What could be the cause of RejectedExecutionException。