问题
I have a program that looks into a single Notepad file which contains information similar to:
Cardiff : 3245658
Bristol : 4726485
Manchester : 4728945
These places and numbers are coming out of a automatic system, and the numbers change every 20 seconds or so.
I need to create a loop(I'm guessing) so that when the numbers change, my program will look back into the notepad file and update the number in the JTextField
P.s I have already created the program so that it looks into the file, gets the information needs and puts it in the correct place, using an ArrayList,
All I need help with is how to make the code automatically update when there is a change in the file, and I need to do this without using any sort of Jbuttons, it just needs to do it by itself.
My whole code as it stands:
package window;
import java.awt.Color;
import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MapTest {
private JFrame frame;
static JTextField txtCardiff;
static JTextField txtBristol;
static JTextField txtSheffield;
static JTextField txtDerby;
static JTextField txtGlasgow;
static JTextField txtFalkirk;
static JTextField txtNewcastle;
static JTextField txtLeeds;
static JTextField txtPreston;
static JTextField txtManchester;
static JTextField txtWolverhampton;
static JTextField txtBirmingham;
static JTextField txtMiltonKeynes;
static JTextField txtPeterborough;
static JTextField txtColindale;
static JTextField txtStepneyGreen;
static JTextField txtSlough;
static JTextField txtFaraday;
static JTextField txtGuildford;
static JTextField txtSouthbank;
static BufferedReader CSVFile = new BufferedReader(new FileReader
("C:/Users/606854007/workspace/NetworkAppTest/jar/window/Cardiff.txt"));
// putting static infront of this Br ' CSVFile' gives:
//Unhandled exception type FileNotFoundException.
//but when i take away the 'static' it causes a problem in the 'FileCheckerWorker' class.
// (Will comment where and what)
ArrayList<String> csv = new ArrayList<String>();
/**
private String output = "";
private String output1 = "";
private String output2 = "";
private String output3 = "";
private String output4 = "";
private String output5 = "";
private String output6 = "";
private String output7 = "";
private String output8 = "";
private String output9 = "";
private String output10 = "";
private String output11 = "";
private String output12 = "";
private String output13 = "";
private String output14 = "";
private String output15 = "";
private String output16 = "";
private String output17 = "";
private String output18 = "";
private String output19 = "";
**/
/** * Launch the application. */
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
} catch (InstantiationException e1) {
e1.printStackTrace();
} catch (IllegalAccessException e1) {
e1.printStackTrace();
} catch (UnsupportedLookAndFeelException e1) {
e1.printStackTrace();
}
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MapTest window = new MapTest();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*
* @throws IOException
*/
public MapTest() throws IOException {
try {
initialize();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
/**
* Initialise the contents of the frame.
*
* @param output
* @throws IOException
*/
private void initialize() throws IOException {
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
csv.add(CSVFile.readLine());
System.out.println(csv.get(0));
System.out.println(csv.get(1));
System.out.println(csv.get(2));
System.out.println(csv.get(3));
System.out.println(csv.get(4));
System.out.println(csv.get(5));
System.out.println(csv.get(6));
System.out.println(csv.get(7));
System.out.println(csv.get(8));
System.out.println(csv.get(9));
System.out.println(csv.get(10));
System.out.println(csv.get(11));
System.out.println(csv.get(12));
System.out.println(csv.get(13));
System.out.println(csv.get(14));
System.out.println(csv.get(15));
System.out.println(csv.get(16));
System.out.println(csv.get(17));
System.out.println(csv.get(18));
System.out.println(csv.get(19));
/**
* JPanel container = new JPanel(); container.add(txtBirmingham);
* container.add(txtBristol); container.add(txtCardiff);
* container.add(txtColindale); container.add(txtDerby);
* container.add(txtFalkirk); container.add(txtGlasgow);
* container.add(txtGuildford); container.add(txtLeeds);
* container.add(txtManchester); container.add(txtMiltonKeynes);
* container.add(txtNewcastle); container.add(txtPeterborough);
* container.add(txtPreston); container.add(txtSheffield);
* container.add(txtSlough); container.add(txtSouthbank);
* container.add(txtStepneyGreen); container.add(txtWolverhampton);
* //container.add(); JScrollPane jsp = new JScrollPane(container);
* frame.add(jsp);
**/
frame = new JFrame();
frame.setBounds(0, 0, 1000, 1086);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
frame.setBackground(Color.CYAN);
txtCardiff = new JTextField();
txtCardiff.setText(csv.get(0));
txtCardiff.setBackground(Color.GREEN);
txtCardiff.setBounds(305, 699, 102, 20);
frame.getContentPane().add(txtCardiff);
txtCardiff.setColumns(10);
txtBristol = new JTextField();
txtBristol.setText(csv.get(1));
txtBristol.setBackground(Color.GREEN);
txtBristol.setBounds(416, 780, 102, 20);
frame.getContentPane().add(txtBristol);
txtBristol.setColumns(10);
txtSheffield = new JTextField();
txtSheffield.setText(csv.get(2));
txtSheffield.setBackground(Color.GREEN);
txtSheffield.setBounds(517, 356, 110, 20);
frame.getContentPane().add(txtSheffield);
txtSheffield.setColumns(10);
txtDerby = new JTextField();
txtDerby.setText(csv.get(3));
txtDerby.setBackground(Color.GREEN);
txtDerby.setBounds(582, 451, 90, 20);
frame.getContentPane().add(txtDerby);
txtDerby.setColumns(10);
txtGlasgow = new JTextField();
txtGlasgow.setText(csv.get(4));
txtGlasgow.setBackground(Color.GREEN);
txtGlasgow.setBounds(250, 94, 102, 20);
frame.getContentPane().add(txtGlasgow);
txtGlasgow.setColumns(10);
txtFalkirk = new JTextField();
txtFalkirk.setText(csv.get(5));
txtFalkirk.setColumns(10);
txtFalkirk.setBackground(Color.GREEN);
txtFalkirk.setBounds(331, 41, 102, 20);
frame.getContentPane().add(txtFalkirk);
txtNewcastle = new JTextField();
txtNewcastle.setText(csv.get(6));
txtNewcastle.setColumns(10);
txtNewcastle.setBackground(Color.GREEN);
txtNewcastle.setBounds(424, 141, 111, 20);
frame.getContentPane().add(txtNewcastle);
txtLeeds = new JTextField();
txtLeeds.setText(csv.get(7));
txtLeeds.setColumns(10);
txtLeeds.setBackground(Color.GREEN);
txtLeeds.setBounds(481, 244, 102, 20);
frame.getContentPane().add(txtLeeds);
txtPreston = new JTextField();
txtPreston.setText(csv.get(8));
txtPreston.setColumns(10);
txtPreston.setBackground(Color.GREEN);
txtPreston.setBounds(356, 221, 102, 20);
frame.getContentPane().add(txtPreston);
txtManchester = new JTextField();
txtManchester.setText(csv.get(9));
txtManchester.setColumns(10);
txtManchester.setBackground(Color.GREEN);
txtManchester.setBounds(394, 394, 124, 20);
frame.getContentPane().add(txtManchester);
txtWolverhampton = new JTextField();
txtWolverhampton.setText(csv.get(10));
txtWolverhampton.setColumns(10);
txtWolverhampton.setBackground(Color.GREEN);
txtWolverhampton.setBounds(360, 486, 153, 20);
frame.getContentPane().add(txtWolverhampton);
txtBirmingham = new JTextField();
txtBirmingham.setText(csv.get(11));
txtBirmingham.setColumns(10);
txtBirmingham.setBackground(Color.GREEN);
txtBirmingham.setBounds(424, 553, 128, 20);
frame.getContentPane().add(txtBirmingham);
txtMiltonKeynes = new JTextField();
txtMiltonKeynes.setText(csv.get(12));
txtMiltonKeynes.setColumns(10);
txtMiltonKeynes.setBackground(Color.GREEN);
txtMiltonKeynes.setBounds(474, 604, 135, 20);
frame.getContentPane().add(txtMiltonKeynes);
txtPeterborough = new JTextField();
txtPeterborough.setText(csv.get(13));
txtPeterborough.setColumns(10);
txtPeterborough.setBackground(Color.GREEN);
txtPeterborough.setBounds(655, 576, 135, 20);
frame.getContentPane().add(txtPeterborough);
txtColindale = new JTextField();
txtColindale.setText(csv.get(14));
txtColindale.setColumns(10);
txtColindale.setBackground(Color.GREEN);
txtColindale.setBounds(541, 699, 107, 20);
frame.getContentPane().add(txtColindale);
txtStepneyGreen = new JTextField();
txtStepneyGreen.setText(csv.get(15));
txtStepneyGreen.setColumns(10);
txtStepneyGreen.setBackground(Color.GREEN);
txtStepneyGreen.setBounds(667, 699, 137, 20);
frame.getContentPane().add(txtStepneyGreen);
txtSlough = new JTextField();
txtSlough.setText(csv.get(16));
txtSlough.setColumns(10);
txtSlough.setBackground(Color.GREEN);
txtSlough.setBounds(525, 756, 102, 20);
frame.getContentPane().add(txtSlough);
txtFaraday = new JTextField();
txtFaraday.setText(csv.get(17));
txtFaraday.setColumns(10);
txtFaraday.setBackground(Color.GREEN);
txtFaraday.setBounds(650, 756, 102, 20);
frame.getContentPane().add(txtFaraday);
txtGuildford = new JTextField();
txtGuildford.setText(csv.get(18));
txtGuildford.setColumns(10);
txtGuildford.setBackground(Color.GREEN);
txtGuildford.setBounds(525, 822, 102, 20);
frame.getContentPane().add(txtGuildford);
txtSouthbank = new JTextField();
txtSouthbank.setText(csv.get(19));
txtSouthbank.setColumns(10);
txtSouthbank.setBackground(Color.GREEN);
txtSouthbank.setBounds(655, 807, 115, 20);
frame.getContentPane().add(txtSouthbank);
JLabel lblNewLabel = new JLabel("New label");
lblNewLabel.setForeground(Color.BLACK);
lblNewLabel.setBackground(Color.BLACK);
lblNewLabel
.setIcon(new ImageIcon(
"C:\\Users\\606854007\\workspace\\NetworkAppTest\\Test\\window\\England_Wales.gif"));
lblNewLabel.setBounds(33, 11, 890, 1086);
frame.getContentPane().add(lblNewLabel);
new FileCheckerWorker(null).execute();
\\ if i dont but null in the '()' then it comes up with an error,
\\and this just makes it execute:
/**
public FileCheckerWorker(MapTest mapTest) {
this.mapTest = mapTest;
}
**/
\\ which is not what I want, I have tried to add commands
\\to run the methods from within:
\\ ' public FileCheckerWorker(MapTest mapTest)' method
\\ but it gives me a null pointer exception,
}
}
Below is the 'FileCheckerWorker' class hoping I've done it right :p
package window;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
import javax.swing.SwingWorker;
public class FileCheckerWorker extends SwingWorker<Object, List<String>> {
private MapTest mapTest;
public FileCheckerWorker(MapTest mapTest) {
this.mapTest = mapTest;
}
@Override
protected void process(List<List<String>> chunks) {
List<String> values = chunks.get(chunks.size() - 1);
mapTest.txtCardiff.setText(values.get(0));
mapTest.txtBristol.setText(values.get(1));
mapTest.txtSheffield.setText(values.get(2));
mapTest.txtDerby.setText(values.get(3));
mapTest.txtGlasgow.setText(values.get(4));
mapTest.txtFalkirk.setText(values.get(5));
mapTest.txtNewcastle.setText(values.get(6));
mapTest.txtLeeds.setText(values.get(7));
mapTest.txtPreston.setText(values.get(8));
mapTest.txtManchester.setText(values.get(9));
mapTest.txtWolverhampton.setText(values.get(10));
mapTest.txtBirmingham.setText(values.get(11));
mapTest.txtMiltonKeynes.setText(values.get(12));
mapTest.txtPeterborough.setText(values.get(13));
mapTest.txtColindale.setText(values.get(14));
mapTest.txtStepneyGreen.setText(values.get(15));
mapTest.txtSlough.setText(values.get(16));
mapTest.txtFaraday.setText(values.get(17));
mapTest.txtGuildford.setText(values.get(18));
mapTest.txtSouthbank.setText(values.get(19));
}
@Override
protected Object doInBackground() throws Exception {
long lastUpdated = -1;
File csvFile = new File("C:/Users/606854007/workspace/NetworkAppTest/Jar/window/Cardiff.txt");
while (true) {
if (csvFile.lastModified() != lastUpdated) {
BufferedReader csvReader = null;
List<String> values = new ArrayList<String>(20);
try {
csvReader = new BufferedReader(new FileReader("C:/Users/606854007/workspace/NetworkAppTest/Jar/window/Cardiff.txt"));
for (int index = 0; index < 20; index++) {
values.add(mapTest.CSVFile.readLine());
}
publish(values);
lastUpdated = csvFile.lastModified();
} finally {
try {
csvReader.close();
} catch (Exception e) {
}
}
Thread.sleep(5000);
System.out.println("Check For Change");
}
}
}
}
UPDATED Both codes to what they are now.
Also when I thought I had the 'doInBackground' working if gave me a NullPointerException on line values.add(mapTest.CSVFile.readLine());
回答1:
Take a look at ScheduledExecutorService. Using this you can schedule some periodic tasks. (in your case will be reading from file at every 20 seconds).
回答2:
Wrap the "look up" code in a SwingWorker, use Thread.sleep to allow the background thread to idle for a given period (say 20 seconds).
Load the contents of the file, determine if it's changed and use the pusblish method to send the results to the process method, which allows you to process the results withing the Event Dispatching Thread
Take a look at SwingWorker for more details
Simple Example
public class PeriodicalWorker extends SwingWorker<Object, String> {
private boolean running = true;
public Object doInBackground() throws Exception {
while (running) {
try {
Thread.sleep(20000);
} catch (Exception exp) {}
// Load the values...
// Check to see if anything needs to updated...
publish(values); // List of String array values
}
return null;
}
public void process(List<String> values) {
// Assign the values to the UI...
}
}
I'm sure you can a "stop" method to set running to false ;)
Updated
The basic concept is very simple. You need to keep track of the last time the file was updated, if the value changes between sleeps, you need to reread the file and update the values on the screen.
This process has been made considerably easier in Java 7, but before that, you could use File#lastModified to check the last modified date/time of the file.
Below is simple example.
public class FileCheckerWorker extends SwingWorker<Object, List<String>> {
@Override
protected void process(List<List<String>> chunks) {
List<String> values = chunks.get(chunks.size() - 1);
txtCardiff.setText(values.get(0));
txtBristol.setText(values.get(1));
txtSheffield.setText(values.get(2));
txtDerby.setText(values.get(3));
txtGlasgow.setText(values.get(4));
txtFalkirk.setText(values.get(5));
txtNewcastle.setText(values.get(6));
txtLeeds.setText(values.get(7));
txtPreston.setText(values.get(8));
txtManchester.setText(values.get(9));
txtWolverhampton.setText(values.get(10));
txtBirmingham.setText(values.get(11));
txtMiltonKeynes.setText(values.get(12));
txtPeterborough.setText(values.get(13));
txtColindale.setText(values.get(14));
txtStepneyGreen.setText(values.get(15));
txtSlough.setText(values.get(16));
txtFaraday.setText(values.get(17));
txtGuildford.setText(values.get(18));
txtSouthbank.setText(values.get(19));
}
@Override
protected Object doInBackground() throws Exception {
long lastUpdated = -1;
File csvFile = new File("...");
while (true) {
if (csvFile.lastModified() != lastUpdated) {
BufferedReader csvReader = null;
List<String> values = new ArrayList<String>(20);
try {
csvReader = new BufferedReader(new FileReader("..."));
for (int index = 0; index < 20; index++) {
values.add(CSVFile.readLine());
}
publish(values);
lastUpdated = csvFile.lastModified();
} finally {
try {
csvReader.close();
} catch (Exception e) {
}
}
Thread.sleep(20000);
}
}
}
}
You would place this at the end of your initialise method with new FileCheckerWorker.execute().
Updated
Instead of making your fields static, pass a reference to of the MapTest to the worker...
import java.awt.Color;
import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MapTest {
private JFrame frame;
protected JTextField txtCardiff;
protected JTextField txtBristol;
protected JTextField txtSheffield;
protected JTextField txtDerby;
protected JTextField txtGlasgow;
protected JTextField txtFalkirk;
protected JTextField txtNewcastle;
protected JTextField txtLeeds;
protected JTextField txtPreston;
protected JTextField txtManchester;
protected JTextField txtWolverhampton;
protected JTextField txtBirmingham;
protected JTextField txtMiltonKeynes;
protected JTextField txtPeterborough;
protected JTextField txtColindale;
protected JTextField txtStepneyGreen;
protected JTextField txtSlough;
protected JTextField txtFaraday;
protected JTextField txtGuildford;
protected JTextField txtSouthbank;
private BufferedReader CSVFile = new BufferedReader(new FileReader("C:/Users/606854007/workspace/NetworkAppTest/jar/window/Cardiff.txt"));
ArrayList<String> csv = new ArrayList<String>();
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
} catch (Exception e1) {
e1.printStackTrace();
}
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MapTest window = new MapTest();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*
* @throws IOException
*/
public MapTest() throws IOException {
try {
initialize();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
/**
* Initialise the contents of the frame.
*
* @param output
* @throws IOException
*/
private void initialize() throws IOException {
frame = new JFrame();
frame.setBounds(0, 0, 1000, 1086);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
frame.setBackground(Color.CYAN);
txtCardiff = new JTextField();
txtCardiff.setBackground(Color.GREEN);
txtCardiff.setBounds(305, 699, 102, 20);
frame.getContentPane().add(txtCardiff);
txtCardiff.setColumns(10);
txtBristol = new JTextField();
txtBristol.setBackground(Color.GREEN);
txtBristol.setBounds(416, 780, 102, 20);
frame.getContentPane().add(txtBristol);
txtBristol.setColumns(10);
txtSheffield = new JTextField();
txtSheffield.setBackground(Color.GREEN);
txtSheffield.setBounds(517, 356, 110, 20);
frame.getContentPane().add(txtSheffield);
txtSheffield.setColumns(10);
txtDerby = new JTextField();
txtDerby.setBackground(Color.GREEN);
txtDerby.setBounds(582, 451, 90, 20);
frame.getContentPane().add(txtDerby);
txtDerby.setColumns(10);
txtGlasgow = new JTextField();
txtGlasgow.setBackground(Color.GREEN);
txtGlasgow.setBounds(250, 94, 102, 20);
frame.getContentPane().add(txtGlasgow);
txtGlasgow.setColumns(10);
txtFalkirk = new JTextField();
txtFalkirk.setColumns(10);
txtFalkirk.setBackground(Color.GREEN);
txtFalkirk.setBounds(331, 41, 102, 20);
frame.getContentPane().add(txtFalkirk);
txtNewcastle = new JTextField();
txtNewcastle.setColumns(10);
txtNewcastle.setBackground(Color.GREEN);
txtNewcastle.setBounds(424, 141, 111, 20);
frame.getContentPane().add(txtNewcastle);
txtLeeds = new JTextField();
txtLeeds.setColumns(10);
txtLeeds.setBackground(Color.GREEN);
txtLeeds.setBounds(481, 244, 102, 20);
frame.getContentPane().add(txtLeeds);
txtPreston = new JTextField();
txtPreston.setColumns(10);
txtPreston.setBackground(Color.GREEN);
txtPreston.setBounds(356, 221, 102, 20);
frame.getContentPane().add(txtPreston);
txtManchester = new JTextField();
txtManchester.setColumns(10);
txtManchester.setBackground(Color.GREEN);
txtManchester.setBounds(394, 394, 124, 20);
frame.getContentPane().add(txtManchester);
txtWolverhampton = new JTextField();
txtWolverhampton.setColumns(10);
txtWolverhampton.setBackground(Color.GREEN);
txtWolverhampton.setBounds(360, 486, 153, 20);
frame.getContentPane().add(txtWolverhampton);
txtBirmingham = new JTextField();
txtBirmingham.setColumns(10);
txtBirmingham.setBackground(Color.GREEN);
txtBirmingham.setBounds(424, 553, 128, 20);
frame.getContentPane().add(txtBirmingham);
txtMiltonKeynes = new JTextField();
txtMiltonKeynes.setColumns(10);
txtMiltonKeynes.setBackground(Color.GREEN);
txtMiltonKeynes.setBounds(474, 604, 135, 20);
frame.getContentPane().add(txtMiltonKeynes);
txtPeterborough = new JTextField();
txtPeterborough.setColumns(10);
txtPeterborough.setBackground(Color.GREEN);
txtPeterborough.setBounds(655, 576, 135, 20);
frame.getContentPane().add(txtPeterborough);
txtColindale = new JTextField();
txtColindale.setColumns(10);
txtColindale.setBackground(Color.GREEN);
txtColindale.setBounds(541, 699, 107, 20);
frame.getContentPane().add(txtColindale);
txtStepneyGreen = new JTextField();
txtStepneyGreen.setColumns(10);
txtStepneyGreen.setBackground(Color.GREEN);
txtStepneyGreen.setBounds(667, 699, 137, 20);
frame.getContentPane().add(txtStepneyGreen);
txtSlough = new JTextField();
txtSlough.setColumns(10);
txtSlough.setBackground(Color.GREEN);
txtSlough.setBounds(525, 756, 102, 20);
frame.getContentPane().add(txtSlough);
txtFaraday = new JTextField();
txtFaraday.setColumns(10);
txtFaraday.setBackground(Color.GREEN);
txtFaraday.setBounds(650, 756, 102, 20);
frame.getContentPane().add(txtFaraday);
txtGuildford = new JTextField();
txtGuildford.setColumns(10);
txtGuildford.setBackground(Color.GREEN);
txtGuildford.setBounds(525, 822, 102, 20);
frame.getContentPane().add(txtGuildford);
txtSouthbank = new JTextField();
txtSouthbank.setColumns(10);
txtSouthbank.setBackground(Color.GREEN);
txtSouthbank.setBounds(655, 807, 115, 20);
frame.getContentPane().add(txtSouthbank);
JLabel lblNewLabel = new JLabel("New label");
lblNewLabel.setForeground(Color.BLACK);
lblNewLabel.setBackground(Color.BLACK);
lblNewLabel.setIcon(new ImageIcon(
"C:\\Users\\606854007\\workspace\\NetworkAppTest\\Test\\window\\England_Wales.gif"));
lblNewLabel.setBounds(33, 11, 890, 1086);
frame.getContentPane().add(lblNewLabel);
new FileCheckerWorker(this).execute();
}
public class FileCheckerWorker extends SwingWorker<Object, List<String>> {
private MapTest mapTest;
public FileCheckerWorker(MapTest mapTest) {
this.mapTest = mapTest;
}
@Override
protected void process(List<List<String>> chunks) {
List<String> values = chunks.get(chunks.size() - 1);
mapTest.txtCardiff.setText(values.get(0));
mapTest.txtBristol.setText(values.get(1));
mapTest.txtSheffield.setText(values.get(2));
mapTest.txtDerby.setText(values.get(3));
mapTest.txtGlasgow.setText(values.get(4));
mapTest.txtFalkirk.setText(values.get(5));
mapTest.txtNewcastle.setText(values.get(6));
mapTest.txtLeeds.setText(values.get(7));
mapTest.txtPreston.setText(values.get(8));
mapTest.txtManchester.setText(values.get(9));
mapTest.txtWolverhampton.setText(values.get(10));
mapTest.txtBirmingham.setText(values.get(11));
mapTest.txtMiltonKeynes.setText(values.get(12));
mapTest.txtPeterborough.setText(values.get(13));
mapTest.txtColindale.setText(values.get(14));
mapTest.txtStepneyGreen.setText(values.get(15));
mapTest.txtSlough.setText(values.get(16));
mapTest.txtFaraday.setText(values.get(17));
mapTest.txtGuildford.setText(values.get(18));
mapTest.txtSouthbank.setText(values.get(19));
}
@Override
protected Object doInBackground() throws Exception {
long lastUpdated = -1;
File csvFile = new File("C:/Users/606854007/workspace/NetworkAppTest/Jar/window/Cardiff.txt");
while (true) {
if (csvFile.lastModified() != lastUpdated) {
BufferedReader csvReader = null;
List<String> values = new ArrayList<String>(20);
try {
csvReader = new BufferedReader(new FileReader("C:/Users/606854007/workspace/NetworkAppTest/Jar/window/Cardiff.txt"));
for (int index = 0; index < 20; index++) {
values.add(mapTest.CSVFile.readLine());
}
publish(values);
lastUpdated = csvFile.lastModified();
} finally {
try {
csvReader.close();
} catch (Exception e) {
}
}
Thread.sleep(5000);
System.out.println("Check For Change");
}
}
}
}
}
来源：https://stackoverflow.com/questions/15198328/java-i-need-to-update-jtextfields-in-a-swing-gui-program