私の問題は解決しました。コードは次のとおりです。
SwingWorkerクラス：
package ths.turnier;
import javax.swing.SwingUtilities;
/**
* This is the 3rd version of SwingWorker (also known as
* SwingWorker 3), an abstract class that you subclass to
* perform GUI-related work in a dedicated thread. For
* instructions on using this class, see:
*
* http://java.sun.com/docs/books/tutorial/uiswing/misc/threads.html
*
* Note that the API changed slightly in the 3rd version:
* You must now invoke start() on the SwingWorker after
* creating it.
*/
public abstract class SwingWorker {
private Object value; // see getValue(), setValue()
private Thread thread;
/**
* Class to maintain reference to current worker thread
* under separate synchronization control.
*/
private static class ThreadVar {
private Thread thread;
ThreadVar(Thread t) { thread = t; }
synchronized Thread get() { return thread; }
synchronized void clear() { thread = null; }
}
private ThreadVar threadVar;
/**
* Get the value produced by the worker thread, or null if it
* hasn't been constructed yet.
*/
protected synchronized Object getValue() {
return value;
}
/**
* Set the value produced by worker thread
*/
private synchronized void setValue(Object x) {
value = x;
}
/**
* Compute the value to be returned by the <code>get</code> method.
*/
public abstract Object construct();
/**
* public void run() { finished(); } Called on the event dispatching thread (not on the worker thread)
* after the <code>construct</code> method has returned.
*/
public void finished() {
}
/**
* A new method that interrupts the worker thread. Call this method
* to force the worker to stop what it's doing.
*/
public void interrupt() {
Thread t = threadVar.get();
if (t != null) {
t.interrupt();
}
threadVar.clear();
}
/**
* Return the value created by the <code>construct</code> method.
* Returns null if either the constructing thread or the current
* thread was interrupted before a value was produced.
*
* @return the value created by the <code>construct</code> method
*/
public Object get() {
while (true) {
Thread t = threadVar.get();
if (t == null) {
return getValue();
}
try {
t.join();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt(); // propagate
return null;
}
}
}
/**
* Start a thread that will call the <code>construct</code> method
* and then exit.
*/
public SwingWorker() {
final Runnable doFinished = new Runnable() {
public void run() { finished(); }
};
Runnable doConstruct = new Runnable() {
public void run() {
try {
setValue(construct());
}
finally {
threadVar.clear();
}
SwingUtilities.invokeLater(doFinished);
}
};
Thread t = new Thread(doConstruct);
threadVar = new ThreadVar(t);
}
/**
* Start the worker thread.
*/
public void start() {
Thread t = threadVar.get();
if (t != null) {
t.start();
}
}
}
MonitoredInputStream：
/**
* A class that monitors the read progress of an input stream.
*
* @author Hermia Yeung "Sheepy"
* @since 2012-04-05 18:42
*/
public class MonitoredInputStream extends FilterInputStream {
private volatile long mark = 0;
private volatile long lastTriggeredLocation = 0;
private volatile long location = 0;
private final int threshold;
private final List<ChangeListener> listeners = new ArrayList<ChangeListener>(4);
/**
* Creates a MonitoredInputStream over an underlying input stream.
* @param in Underlying input stream, should be non-null because of no public setter
* @param threshold Min. position change (in byte) to trigger change event.
*/
public MonitoredInputStream(InputStream in, int threshold) {
super(in);
this.threshold = threshold;
}
/**
* Creates a MonitoredInputStream over an underlying input stream.
* Default threshold is 16KB, small threshold may impact performance impact on larger streams.
* @param in Underlying input stream, should be non-null because of no public setter
*/
public MonitoredInputStream(InputStream in) {
super(in);
this.threshold = 1024*16;
}
public void addChangeListener(ChangeListener l) { if (!listeners.contains(l)) listeners.add(l); }
public void removeChangeListener(ChangeListener l) { listeners.remove(l); }
public long getProgress() { return location; }
protected void triggerChanged( final long location ) {
if ( threshold > 0 && Math.abs( location-lastTriggeredLocation ) < threshold ) return;
lastTriggeredLocation = location;
if (listeners.size() <= 0) return;
try {
final ChangeEvent evt = new ChangeEvent(this);
for (ChangeListener l : listeners) l.stateChanged(evt);
} catch (ConcurrentModificationException e) {
triggerChanged(location); // List changed? Let's re-try.
}
}
@Override public int read() throws IOException {
final int i = super.read();
if ( i != -1 ) triggerChanged( location++ );
return i;
}
@Override public int read(byte[] b, int off, int len) throws IOException {
final int i = super.read(b, off, len);
if ( i > 0 ) triggerChanged( location += i );
return i;
}
@Override public long skip(long n) throws IOException {
final long i = super.skip(n);
if ( i > 0 ) triggerChanged( location += i );
return i;
}
@Override public void mark(int readlimit) {
super.mark(readlimit);
mark = location;
}
@Override public void reset() throws IOException {
super.reset();
if ( location != mark ) triggerChanged( location = mark );
}
}
これを使用する方法：
void updateProgressWknAdd(final int i)
{
Runnable doSetProgress = new Runnable() {
public void run() {
progressWknAdd.setValue(i);
}
};
SwingUtilities.invokeLater(doSetProgress);
}
Object doWorkWkn(String pfad) {
// Code which reads file + setting the max of jprogressbar to file size. and:
final MonitoredInputStream mis = new MonitoredInputStream(fis);
mis.addChangeListener( new ChangeListener() { @Override public void stateChanged(ChangeEvent e) {
updateProgressWknRead((int) mis.getProgress());
}});
}
ワーカーの使用方法：
SwingWorker worker = new SwingWorker() {
public Object construct() {
return doWorkWkn(pfad_zur_datei);
}
public void finished() {
frame_progressbar.setVisible(false);
}
};
worker.start();
swingWorkerは、終了するまでdoWorkWknを実行します。その後、jFrameは非表示に設定されます。doWorkWkn（）はファイルを読み取り、changeListenerを追加します。これにより、変更のたびにプログレスバーが更新されます。