我有一个程序可以查看单个记事本文件,其中包含类似于以下信息:
Cardiff : 3245658
Bristol : 4726485
Manchester : 4728945
这些地点和数字来自一个自动系统,数字每 20 秒左右变化一次。我需要创建一个循环(我猜),这样当数字改变时,我的程序将回顾记事本文件并更新JTextField
Ps 我已经创建了程序,以便它查看文件,获取所需信息并将其放在正确的位置,使用 ArrayList,
我需要帮助的是如何在文件发生更改时自动更新代码,我需要在不使用任何类型的情况下执行此操作Jbuttons
,它只需要自己完成即可。
我的整个代码:
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,
}
}
下面是“FileCheckerWorker”类,希望我做对了: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");
}
}
}
}
将这两个代码更新为现在的样子。
另外,当我认为如果在行 values.add(mapTest.CSVFile.readLine()) 上给了我一个 NullPointerException 时,我的“doInBackground”正在工作。