testFileHandler.java Source code

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Here is the source code for testFileHandler.java

Source

import java.util.Scanner;
import java.io.*;
import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
/*
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/**
 *
 * @author ChathuraDR
 */
public class testFileHandler {
    private Scanner x;

    public void readFile(String path, javax.swing.JTextArea textField) {

        Scanner sc = new Scanner(System.in);
        BufferedReader br = null; //used BufferedReader to set Data to the textField line by line that passed as a parameter.
        String line;

        try {
            br = new BufferedReader(new FileReader(path)); //FileReader read the content of the file from that given path,and return value pass to the BufferedReader.
            while ((line = br.readLine()) != null) { // reading line by line untill end of the lines
                textField.append(line + '\n'); //append that line get at a time and move the cursor to the next line
            }

        } catch (Exception e) {
            System.out.println(e);
        }
    }

    // function to encrypt the data that given,here's i get 3 parameters.
    public void encrypt(String message, String secretKey, javax.swing.JTextArea ciphertextField) throws Exception {

        MessageDigest md = MessageDigest.getInstance("SHA-1");
        byte[] digestOfPassword = md.digest(secretKey.getBytes("utf-8"));
        byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);

        SecretKey key = new SecretKeySpec(keyBytes, "DESede");
        Cipher cipher = Cipher.getInstance("DESede");
        cipher.init(Cipher.ENCRYPT_MODE, key);
        // Encode the string into bytes using utf-8
        byte[] plainTextBytes = message.getBytes("utf-8");
        // Encrypt
        byte[] buf = cipher.doFinal(plainTextBytes);
        // Encode bytes to base64 to get a string
        byte[] base64Bytes = Base64.encodeBase64(buf);
        String base64EncryptedString = new String(base64Bytes);

        ciphertextField.setText(base64EncryptedString);
    }

    public void decrypt(String encryptedText, String secretKey, javax.swing.JTextArea plainTextField)
            throws Exception {

        byte[] message = Base64.decodeBase64(encryptedText.getBytes("utf-8"));

        MessageDigest md = MessageDigest.getInstance("SHA-1");
        byte[] digestOfPassword = md.digest(secretKey.getBytes("utf-8"));
        byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);

        SecretKey key = new SecretKeySpec(keyBytes, "DESede");
        Cipher decipher = Cipher.getInstance("DESede");
        decipher.init(Cipher.DECRYPT_MODE, key);

        byte[] plainText = decipher.doFinal(message);
        plainTextField.setText(new String(plainText, "UTF-8"));
    }

    public void writeFile(String path, javax.swing.JTextArea textField) throws IOException {

        FileWriter fw = new FileWriter(path); //create a file writer to write to the path
        try (PrintWriter pw = new PrintWriter(fw)) {

            String s[] = textField.getText().split("\\r?\\n"); //get the text fileds characters line by line and put them into an arry so that we can write those text fields as it is.
            ArrayList<String> arrList = new ArrayList<>(Arrays.asList(s));
            for (int i = 0; i < textField.getLineCount(); i++) {
                pw.println(arrList.get(i)); //get the string in that array one by one and write them into the file that opened.
            }
            pw.close(); // close the file when writting is done.
        } catch (Exception e) {
            System.out.println(e);
        }

    }

}