文字列を要求してからテキストファイルに書き込むこの単純な GUI がありますが、入力が指定されていない場合、JLabel にエラーメッセージが表示され、そのエラーメッセージを 5 秒間保持したい
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.*;
import javax.swing.JFrame;
import net.miginfocom.swing.MigLayout;
public class Q1 extends JFrame {
private JLabel lblString, lblMessage;
private JTextField txtString;
private JButton btnStore;
private JPanel thePanel;
public static void main(String[] args) {
new Q1();
}// End of main
public Q1() {
super("Store your text");
this.setSize(600, 100);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
thePanel = new JPanel(new MigLayout());
lblString = new JLabel("Enter Your Text :");
txtString = new JTextField(50);
btnStore = new JButton("Store");
// Listener for Store Button
ListenerForButton lForButton = new ListenerForButton();
btnStore.addActionListener(lForButton);
lblMessage = new JLabel();
thePanel.add(lblString);
thePanel.add(txtString, "wrap");
thePanel.add(btnStore, "skip,split2");
thePanel.add(lblMessage, "gapleft 200");
this.add(thePanel);
this.setResizable(false);
this.setVisible(true);
}// End of constructor
// Listener implement
public class ListenerForButton implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btnStore) {
if (txtString.getText().equals("")) {
lblMessage.setText("ERROR-NO Text is given !");
lblMessage.setForeground(Color.red);
} else {
try {
String str = txtString.getText();
File file = new File("appending-Text-File.txt");
// if file doesnt exists, then create it
if (!file.exists()) {
file.createNewFile();
}
FileWriter fileWritter = new FileWriter(file.getName(),
true);
BufferedWriter bufferWritter = new BufferedWriter(
fileWritter);
bufferWritter.newLine();// Write a new line
bufferWritter.write(str);
bufferWritter.close();
lblMessage.setText("String is successfully stored !");
txtString.setText("");
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}// End actionPerfomred
}
}// End of Class