假设应用程序读取数据文件,从用户那里获取一些输入(通过GUI),从大型数据库中获取其他数据,然后进行冗长的分析。
按照建议,我将耗时的部分(数据库管理和实际分析)移到了SwingWorker
实例中。现在,执行数据库管理的第一部分工作正常(请参见下面的代码):
dialog.addWindowListener(new WindowAdapter() {
@Override
public void windowClosed(WindowEvent e) {
final File dbFile = dialog.getFile();
frame.activateDisGlass("Loading DB, please wait...");
SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() throws Exception {
try {
dbman = new DbManager(dbFile);
} catch (SQLException e1) {
System.err.println("Unable to load the chosen database, see details below:");
e1.printStackTrace();
}
return null;
}
@Override
protected void done(){
frame.deactivateDisGlass();
}
};
worker.execute();
}
});
但是,相同的策略在分析情况下无法正常工作。由于分析篇幅很长,并且涉及许多自定义类,因此我将总结一下情况。以下代码位于一个自定义类中,该类与GUI交互以获取用户输入,使用触发计算analyzeButton
,该初始化创建多个对象的创建,其中一个对象包含线程池以并行执行独立分析:
// INITIATE ANALYSIS
analyzeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
for (int i = 0; i < annots.length; i++) {
annots[i] = (ANNOT_TYPE) combos[i].getSelectedItem();
}
// Validate the column annotations
List<ANNOT_TYPE> annotlist = Arrays.asList(annots);
if (!annotlist.contains(ANNOT_TYPE.R) &&
!(annotlist.contains(ANNOT_TYPE.OS1) &&
annotlist.contains(ANNOT_TYPE.OS2))) {
JOptionPane
.showMessageDialog(
null,
"<html>Missing annotation!<p>"
+ "<p> Please make sure you have annotated the datafile correctly...",
"Missing annotation!",
JOptionPane.ERROR_MESSAGE);
return;
}
// Validate DB selection
if (descPanel.getDBManager() == null) {
JOptionPane
.showMessageDialog(
null,
"<html>No database not selected for analysis! <p>"
+ "<p> Please select and load a database..",
"Database error", JOptionPane.ERROR_MESSAGE);
return;
}
// Activate progress indicator
frame.getMainFrame().activateInfiGlass();
SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
@Override
protected Void doInBackground() {
try {
// register parameters
param.addParam(AnalysisParams.value_key,descPanel.getValueTypeComboIndex());
param.addParam(AnalysisParams.sepchar_key,descPanel.getSepCharComboIndex());
paramPanel.registerParams();
StringBuilder sb = new StringBuilder("Data preview completed, initiating analysis...");
sb.append(System.lineSeparator())
.append("... column annotations: ")
.append(Arrays.toString(annots));
logger.info(sb.toString() + System.lineSeparator());
// Create dataset; to be passed on to SwingWorker which will
// execute the analysis
ds = new Dataset();
for (String[] line : data)
ds.addRow(line, annots);
System.out.println("Dataset parsed...");
logger.info("Dataset parsing complete "
+ System.lineSeparator()
+ ds.toString()
+ System.lineSeparator());
conserv = new ConcurrencyService(ds, descPanel.getDBManager());
conserv.serve();
DebugToolbox.dumpScores();
}
} catch (InterruptedException e) {
logger.severe("Concurrency service interrupted"
+ System.lineSeparator()
+ e.getStackTrace()
+ System.lineSeparator());
System.err.println("Interrupt exception!!");
}
return null;
}
@Override
protected void done() {
if(!conserv.isDone())
logger.warning("Concurrency Service is not done!" +
System.lineSeparator());
logger.info("#DEBUG: Conserv should have been terminated by now..." + System.lineSeparator());
frame.getMainFrame().deactivateInfiGlass();
}
};
worker.execute();
}
});
那么问题是什么,您可能会问...问题done()
是从来没有调用过,SwingWorker
而应用程序实际上只是挂起,等待某些东西。我可以看到,doInBackground()
自将分数转储到日志文件以来,该操作已经完成(这是该方法的最后一步,但是我看不到预期的输出done()
我从jvisualvm得到了一个线程转储,这是相关的位:
"SwingWorker-pool-1-thread-2" daemon prio=5 tid=0x00007f8ce5819000 nid=0x860b waiting on condition [0x0000000129593000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x0000000705a2c978> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2043)
at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1068)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
Locked ownable synchronizers:
- None
前一个SwingWorker
(加载数据库的那个)具有完全相同的状态和堆栈跟踪,这使我认为确实SwingWorker
已经完成了工作,但是应用程序的其余部分未得到通知。
相似的问题:我注意到两个相关的问题,它们之间存在本质差异
JDK-7 SwingWorker僵局?-我SwingWorker
的(或应该)彼此独立。
SwingWorker挂在Unsafe.park()上-我SwingWorker
不与GUI交互或返回任何内容(除外null
),所以它应该与无关get()
,对吧?
有想法吗?
您声明:
所以它应该与get()没有关系,对吗?
不是这样 调用是关键,get()
否则您将无法捕获和处理SwingWorker的doInBackground方法中引发的任何异常。因此,我建议您不要忘记get()
在done()
方法中调用SwingWorker ,或者在方法中首先调用它,也不要忘记捕获和分析此方法引发的所有异常。
本文收集自互联网,转载请注明来源。
如有侵权,请联系[email protected] 删除。
我来说两句