我正在编写一个使用Random.ORG api的程序。当我点击计算按钮时，JProgressBar会在操作完成后立即启动并保持冻结直到此刻。
我尝试了额外的try-catch子句，if语句和bool-gates。他们都没有工作，我怎么能解决它？
kazananiBelirleButon.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
progressBar.setVisible(true);
progressBar.setIndeterminate(true);
try {
HashMap<String, Object> randoms = randSonuc.generateSignedIntegers(5, 0, 10);
System.out.println(randoms.toString());
String test = randoms.toString().substring(randoms.toString().indexOf("{r")+1, randoms.toString().indexOf(", da")).replace("random=", "{\"random\":") + "}";
System.out.println(tarihiYazdir(test,14));
cekilisTarihiTextPane.setText(tarihiYazdir(test,2).toString());
sonucPane.setText("\n"+sonuclariYazdir(test,0));
} catch (RandomOrgSendTimeoutException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgKeyNotRunningError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgInsufficientRequestsError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgInsufficientBitsError e1) {
System.out.print("lol");
e1.printStackTrace();
} catch (RandomOrgBadHTTPResponseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgRANDOMORGError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgJSONRPCError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (MalformedURLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
});
答案 0 :(得分：3)
Swing是单线程的。调用侦听器，绘制/更新UI都发生在名为Event Dispatch Thread（EDT）的单个线程上。
由于您在事件处理程序代码中完成了所有工作，因此在您从方法（actionPerformed()）返回之前无法更新Swing UI。
阅读本教程：Concurrency in Swing
您应该做的是在单独的线程中完成耗时的工作，并且只在EDT中执行简短的任务（例如UI更新）。
另请查看SwingWorker类，该类旨在在后台线程中执行冗长的GUI交互任务。
答案 1 :(得分：2)
尝试在您的方法中使用swing worker。 Swing Worker
这是旧版swing工作者的一个例子。您需要将SwingWorker类添加到项目中：
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();
/**
* 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();
}
}
}
然后在里面添加你的逻辑：
SwingWorker worker = new SwingWorker() {
@Override
public Object construct() {
// add your code here
progressBar.setVisible(true);
progressBar.setIndeterminate(true);
// and so on...
return 0;
}
};
worker.start();
所以结果应该是这样的（注意这是未经测试的代码）：
kazananiBelirleButon.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
SwingWorker worker = new SwingWorker() {
@Override
public Object construct() {
progressBar.setVisible(true);
progressBar.setIndeterminate(true);
try {
HashMap<String, Object> randoms = randSonuc.generateSignedIntegers(5, 0, 10);
System.out.println(randoms.toString());
String test = randoms.toString().substring(randoms.toString().indexOf("{r")+1, randoms.toString().indexOf(", da")).replace("random=", "{\"random\":") + "}";
System.out.println(tarihiYazdir(test,14));
cekilisTarihiTextPane.setText(tarihiYazdir(test,2).toString());
sonucPane.setText("\n"+sonuclariYazdir(test,0));
} catch (RandomOrgSendTimeoutException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgKeyNotRunningError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgInsufficientRequestsError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgInsufficientBitsError e1) {
System.out.print("lol");
e1.printStackTrace();
} catch (RandomOrgBadHTTPResponseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgRANDOMORGError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (RandomOrgJSONRPCError e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (MalformedURLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
return 0;
}
};
worker.start();
});