Create ReadWriteFile.java

ReadWriteFile.java

@@ -0,0 +1,129 @@
+package _22_03_2022;
+
+import java.awt.BorderLayout;
+import java.awt.EventQueue;
+
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.border.EmptyBorder;
+import javax.swing.JButton;
+import javax.swing.JTextField;
+import java.awt.event.ActionListener;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.awt.event.ActionEvent;
+import javax.swing.JTextArea;
+import javax.swing.JScrollPane;
+import java.awt.Font;
+import java.awt.TextField;
+
+public class ReadWriteFile extends JFrame {
+
+	private JPanel contentPane;
+	JTextArea textArea;
+	private JScrollPane scrollPane;
+	private JTextField textField;
+	private JButton btnAdd;
+
+	/**
+	 * Launch the application.
+	 */
+	public static void main(String[] args) {
+		EventQueue.invokeLater(new Runnable() {
+			public void run() {
+				try {
+					ReadWriteFile frame = new ReadWriteFile();
+					frame.setVisible(true);
+				} catch (Exception e) {
+					e.printStackTrace();
+				}
+			}
+		});
+	}
+
+	/**
+	 * Create the frame.
+	 */
+	public ReadWriteFile() {
+		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		setBounds(100, 100, 579, 435);
+		contentPane = new JPanel();
+		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
+		setContentPane(contentPane);
+		contentPane.setLayout(null);
+
+		JButton btnNewButton = new JButton("View");
+		btnNewButton.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				textArea.setText(readFile("A.txt"));
+			}
+		});
+		btnNewButton.setBounds(459, 291, 73, 42);
+		contentPane.add(btnNewButton);
+
+		scrollPane = new JScrollPane();
+		scrollPane.setBounds(33, 11, 499, 269);
+		contentPane.add(scrollPane);
+
+		textArea = new JTextArea();
+		textArea.setFont(new Font("Times New Roman", Font.PLAIN, 14));
+		scrollPane.setViewportView(textArea);
+
+		textField = new JTextField();
+		textField.setBounds(33, 297, 286, 30);
+		contentPane.add(textField);
+		textField.setColumns(10);
+
+		btnAdd = new JButton("Add");
+		btnAdd.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				writeFile("A.txt", textField.getText());
+				textField.setText("");
+			}
+		});
+		btnAdd.setBounds(361, 291, 73, 42);
+		contentPane.add(btnAdd);
+	}
+
+	public String readFile(String fileName) {
+		File fileIn = new File("A.txt");
+    	String content = "";
+    	String line = "";
+		try {
+			FileReader fileReader = new FileReader(fileIn, StandardCharsets.UTF_8);
+			BufferedReader bufferedReader = new BufferedReader(fileReader);
+			while((line = bufferedReader.readLine()) != null) {
+				content = content + line + "\n";
+			}
+			bufferedReader.close();
+		} catch (Exception e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} 
+
+    	return content;
+	}
+
+	public void writeFile(String fileName, String s) {
+		String OldContent = readFile(fileName);
+		File fileOut = new File(fileName);
+        FileWriter Filewriter;
+		try {
+			Filewriter = new FileWriter(fileOut, StandardCharsets.UTF_8);
+			BufferedWriter bufferedWriter = new BufferedWriter(Filewriter);
+			bufferedWriter.write(OldContent + s);
+			textArea.setText(readFile("A.txt"));
+			bufferedWriter.close();
+			textArea.setText(readFile(fileName));
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+}