问题
Right now, my main just calls a gui with 10 rows. Based on how many of those rows have text, 1 of 9 classes is called (two rows must have text). The called class performs calculations that I\'d like to have the progress bar tied to. Here is an example of one of the called classes (each class is similar, but different enough to warrant a new class.) I believe the problem is a violation of EDT rules, but all the examples I\'ve seen on them involve a main argument. The frame appears when the code is run, but the progress bar doesn\'t update until all calculations are completed.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class twoLoan extends JFrame {
static JFrame progressFrame;
static JProgressBar progressBar;
static Container pane;
double amountSaved = 0;
int i = 0;
public void runCalcs(Double MP, Double StepAmt,
Double L1, Double L2, Double C1, Double C2,
Double IM1, Double IM2, Double M1Start, Double M2Start) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
}
int iterations = (int) (MP - (M1Start * M2Start));
//Create all components
progressFrame = new JFrame(\"Calculation Progress\");
progressFrame.setSize(300, 100);
pane = progressFrame.getContentPane();
pane.setLayout(null);
progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
progressBar = new JProgressBar(0, iterations);
//Add components to pane
pane.add(progressBar);
//Position controls (X, Y, width, height)
progressBar.setBounds(10, 10, 280, 20);
//Make frame visible
progressFrame.setResizable(false); //No resize
progressFrame.setVisible(true);
double M1 = M1Start;
double M2 = M2Start;
// Set MinLoop as maximum to start
// Loan 1
double N1 = (Math.log10(1 - IM1 * L1 / M1) * -1) / Math.log10(1 + IM1);
double M1Sum = M1 * N1;
// Loan 2
double N2 = (Math.log10(1 - IM2 * L2 / M2) * -1) / Math.log10(1 + IM2);
double M2Sum = M2 * N2;
double minLoop = M1Sum + M2Sum;
double MTotal = 0;
// Define variables for mins
double MP1 = 0;
double MP2 = 0;
double NP1 = 0;
double NP2 = 0;
double MP1Sum = 0;
double MP2Sum = 0;
while (M1 <= MP - M2Start && M2 >= M2Start) {
N1 = (Math.log10(1 - IM1 * L1 / M1) * -1) / Math.log10(1 + IM1);
M1Sum = N1 * M1;
N2 = (Math.log10(1 - IM2 * L2 / M2) * -1) / Math.log10(1 + IM2);
M2Sum = N2 * M2;
MTotal = M1Sum + M2Sum;
if (MTotal < minLoop) {
minLoop = MTotal;
MP1 = M1;
MP2 = M2;
NP1 = N1;
NP2 = N2;
MP1Sum = M1Sum;
MP2Sum = M2Sum;
} // end if
M1 = M1 + StepAmt;
M2 = MP - M1;
// Reset monthly sums
M1Sum = 0;
M2Sum = 0;
i++;
progressBar.setValue(i);
progressBar.repaint();
if (i >= iterations) {
progressFrame.dispose();
}
} // end while
// if there\'s a value for current payments, calculate amount saved
if (C1 > 0) {
double CN1 = (Math.log10(1 - IM1 * L1 / C1) * -1) / Math.log10(1 + IM1);
double CT1 = CN1 * C1;
double CN2 = (Math.log10(1 - IM2 * L2 / C2) * -1) / Math.log10(1 + IM2);
double CT2 = CN2 * C2;
double CTotal = CT1 + CT2;
amountSaved = CTotal - minLoop;
}
} // end method runCalcs
//Workbook wb = new HSSFWorkbook();
public double savedReturn() {
return amountSaved;
}
} // end class twoLoans
回答1:
SwingWorker is ideal for this. The example below performs a simple iteration in the background, while reporting progress and intermediate results in a window. You can pass whatever parameters you need in a suitable SwingWorker constructor.
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.text.DecimalFormat;
import java.util.List;
import javax.swing.*;
/** @see http://stackoverflow.com/questions/4637215 */
public class TwoRoot extends JFrame {
private static final String s = "0.000000000000000";
private JProgressBar progressBar = new JProgressBar(0, 100);
private JLabel label = new JLabel(s, JLabel.CENTER);
public TwoRoot() {
this.setLayout(new GridLayout(0, 1));
this.setTitle("√2");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(progressBar);
this.add(label);
this.setSize(161, 100);
this.setLocationRelativeTo(null);
this.setVisible(true);
}
public void runCalc() {
progressBar.setIndeterminate(true);
TwoWorker task = new TwoWorker();
task.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent e) {
if ("progress".equals(e.getPropertyName())) {
progressBar.setIndeterminate(false);
progressBar.setValue((Integer) e.getNewValue());
}
}
});
task.execute();
}
private class TwoWorker extends SwingWorker<Double, Double> {
private static final int N = 5;
private final DecimalFormat df = new DecimalFormat(s);
double x = 1;
@Override
protected Double doInBackground() throws Exception {
for (int i = 1; i <= N; i++) {
x = x - (((x * x - 2) / (2 * x)));
setProgress(i * (100 / N));
publish(Double.valueOf(x));
Thread.sleep(1000); // simulate latency
}
return Double.valueOf(x);
}
@Override
protected void process(List<Double> chunks) {
for (double d : chunks) {
label.setText(df.format(d));
}
}
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
TwoRoot t = new TwoRoot();
t.runCalc();
}
});
}
}
回答2:
I think you premonition is right, you need to adhere to Swing threading rules.
So what to do?
First, I am not sure how your app is designed exactly. You say that you have a main frame with a bunch of rows, and potentially each could potentially call one of 9 classes, and they all look like the one above. It seems that these classes will generate their own JFrame. I guess that this new frame is solely used for the progress bar. I will assume that this is the design and will suggest accordingly.
I suggest that you perform a couple actions in instances of Runnable, and you drop those Runnable instances into SwingUtilities.invokeLater to have them run on the EDT. At the same time, I would take the time to reorganize your code for ease if reading.
- move the creation of your GUI bits into a method:
public void createComponents () {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
//Create all components
progressFrame = new JFrame("Calculation Progress");
progressFrame.setSize(300, 100);
pane = progressFrame.getContentPane();
pane.setLayout(null);
progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
progressBar = new JProgressBar(0, iterations);
//Add components to pane
pane.add(progressBar);
//Position controls (X, Y, width, height)
progressBar.setBounds(10, 10, 280, 20);
//Make frame visible
progressFrame.setResizable(false); //No resize
progressFrame.setVisible(true);
}
});
}
- Then I would methodize the two GUI actions that you have in your calc:
private void updateProgressBar(final int i) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
progressBar.setValue(i);
//no need for the following
//progressBar.repaint();
}
});
}
private void killDialog() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
progressFrame.setVisible(false);
}
});
}
- Finally, replace where the code contained in these new methods with calls to the methods.
回答3:
Thanks for the help. I started with trying to use the first response, but I couldn't get the bar to run concurrently, and it ran when the program finished. I'm sure it would work, but I wasn't able to figure it out. Using trashgod's response and some other examples, I was able to get it to work using SwingWorker. Unfortunately, I don't totally understand how it works, but I'll take it for now.
The gui and method to run the calculations are called in another class first:
iterations = (int) (MPay - (M1Start + M2Start));
twoLoan myLoan = new twoLoan();
myLoan.createGui(iterations);
myLoan.runCalcs(MPay, Step, L1, L2, C1, C2, IM1, IM2, M1Start, M2Start);
Then it runs as follows:
public class twoLoan extends JFrame {
JFrame progressFrame;
JProgressBar progressBar;
JLabel label = new JLabel("Calculating...");;
Container pane;
double amountSaved = 0;
int i = 0;
int iterations;
public void createGui(int iterations) {
//Create all components
progressFrame = new JFrame("Calculation Progress");
progressFrame.setSize(300, 100);
pane = progressFrame.getContentPane();
pane.setLayout(null);
label = new JLabel("Calculating...");
label.setBounds(115, 35, 200, 25);
progressBar = new JProgressBar(0, iterations);
progressBar.setBounds(10, 10, 280, 20);
progressBar.setStringPainted(true);
//Add components to pane
pane.add(progressBar);
pane.add(label);
//Make frame visible
progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
progressFrame.setResizable(false); //No resize
progressFrame.setLocationRelativeTo(null);
progressFrame.setVisible(true);
}
public void runCalcs (double MP, double StepAmt, double L1, double L2,
double C1, double C2, double IM1, double IM2, double M1Start, double M2Start) {
progressBar.setIndeterminate(false);
TwoWorker task = new TwoWorker(MP, StepAmt, L1, L2, C1, C2, IM1, IM2, M1Start, M2Start);
task.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent e) {
if ("progress".equals(e.getPropertyName())) {
progressBar.setIndeterminate(false);
progressBar.setValue((Integer) e.getNewValue());
}
}
});
task.execute();
} //end method runCalcs
public class TwoWorker extends SwingWorker<Double, Double> {
private final double MP, StepAmt,L1, L2,
C1, C2, IM1, IM2, M1Start, M2Start;
public TwoWorker(double MPa, double StepAmta, double L1a, double L2a,
double C1a, double C2a, double IM1a, double IM2a, double M1Starta, double M2Starta) {
MP = MPa;
StepAmt = StepAmta;
L1 = L1a;
L2 = L2a;
C1 = C1a;
C2 = C2a;
IM1 = IM1a;
IM2 = IM2a;
M1Start = M1Starta;
M2Start = M2Starta;
}
@Override
protected Double doInBackground() {
double M1 = M1Start;
double M2 = M2Start;
// Set MinLoop as maximum to start
// Loan 1
double N1 = (Math.log10(1 - IM1 * L1 / M1) * -1)/Math.log10(1 + IM1);
double M1Sum = M1 * N1;
// Loan 2
double N2 = (Math.log10(1 - IM2 * L2 / M2) * -1)/Math.log10(1 + IM2);
double M2Sum = M2 * N2;
double minLoop = M1Sum + M2Sum;
double MTotal = 0;
// Define variables for mins
double MP1 = 0;
double MP2 = 0;
double NP1 = 0;
double NP2 = 0;
double MP1Sum = 0;
double MP2Sum = 0;
while ( M1 <= MP - M2Start && M2 >= M2Start ) {
N1 = (Math.log10(1 - IM1 * L1 / M1) * -1)/Math.log10(1 + IM1);
M1Sum = N1 * M1;
N2 = (Math.log10(1 - IM2 * L2 / M2) * -1)/Math.log10(1 + IM2);
M2Sum = N2 * M2;
MTotal = M1Sum + M2Sum;
if (MTotal < minLoop) {
minLoop = MTotal;
MP1 = M1;
MP2 = M2;
NP1 = N1;
NP2 = N2;
MP1Sum = M1Sum;
MP2Sum = M2Sum;
} // end if
i++;
progressBar.setValue(i);
M1 = M1 + StepAmt;
M2 = MP - M1;
// Reset monthly sums
M1Sum = 0;
M2Sum = 0;
} // end while
System.out.printf("MP1 = %.2f\n", MP1);
System.out.printf("MP2 = %.2f\n", MP2);
System.out.printf("NP1 = %.2f\n", NP1);
System.out.printf("NP2 = %.2f\n", NP2);
System.out.printf("MP1Sum = %.2f\n", MP1Sum);
System.out.printf("MP2Sum = %.2f\n", MP2Sum);
System.out.printf("MTotal = %.2f\n", minLoop);
System.out.printf("i = %d\n",i);
System.out.printf("M1Start = %.2f\n", M1Start);
System.out.printf("M2Start = %.2f\n", M2Start);
System.out.printf("MP= %.2f\n",MP);
// if there's a value for current payments, calculate amount saved
if( C1 > 0 ) {
double CN1 = (Math.log10(1 - IM1 * L1 / C1) * -1)/Math.log10(1 + IM1);
double CT1 = CN1 * C1;
double CN2 = (Math.log10(1 - IM2 * L2 / C2) * -1)/Math.log10(1 + IM2);
double CT2 = CN2 * C2;
double CTotal = CT1 + CT2;
amountSaved = CTotal - minLoop;
} // end if
return null;
} // end doInBackGround
@Override
protected void done() {
label.setBounds(133, 35, 200, 25);
label.setText("Done!");
}
} // end TwoWorker
public double savedReturn() {
return amountSaved;
}
} // end class twoLoans
来源：https://stackoverflow.com/questions/4637215/can-a-progress-bar-be-used-in-a-class-outside-main