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1package TestParallel;
2
3import java.io.File;
4import java.io.FileInputStream;
5import java.io.FileOutputStream;
6import java.io.ObjectOutputStream;
7import java.util.concurrent.ExecutorService;
8import java.util.concurrent.Executors;
9import java.util.concurrent.TimeUnit;
10import java.util.logging.Level;
11import java.util.logging.Logger;
12import javax.crypto.Cipher;
13import javax.crypto.CipherOutputStream;
14import javax.crypto.KeyGenerator;
15import javax.crypto.SecretKey;
16
17/**
18 *
19 * @author Sohel Rana
20 */
21public class Executor {
22
23    public void encrypt(File fname) throws Exception {
24        KeyGenerator keyGen = KeyGenerator.getInstance("AES");
25        keyGen.init(256);  //using AES-256
26        SecretKey key = keyGen.generateKey();  //generating key
27        //  System.out.println("Key = " + bytesToHex(key.getEncoded()));
28        Cipher aesCipher = Cipher.getInstance("AES");  //getting cipher for AES
29        aesCipher.init(Cipher.ENCRYPT_MODE, key);  //initializing cipher for encryption with key
30
31        //creating file output stream to write to file
32        try (FileOutputStream fos = new FileOutputStream(fname + ".aes")) {
33            //creating object output stream to write objects to file
34            ObjectOutputStream oos = new ObjectOutputStream(fos);
35            oos.writeObject(key);  //saving key to file for use during decryption
36
37            //creating file input stream to read contents for encryption
38            try (FileInputStream fis = new FileInputStream(fname)) {
39                //creating cipher output stream to write encrypted contents
40                try (CipherOutputStream cos = new CipherOutputStream(fos, aesCipher)) {
41                    int read;
42                    byte buf[] = new byte[4096];
43                    while ((read = fis.read(buf)) != -1) //reading from file
44                    {
45                        cos.write(buf, 0, read);  //encrypting and writing to file
46                    }
47                }
48            }
49            //  fname.delete();
50        }
51
52    }
53
54    public static void main(final String[] args) throws InterruptedException {
55        final ExecutorService pool = Executors.newFixedThreadPool(4);
56
57        File file1 = new File("C:\Users\Sohel Rana\Desktop\test\33 - Overflow Menu.mp4");
58        File file2 = new File("C:\Users\Sohel Rana\Desktop\test\Java Cryptography Tutorials 1 AES Encryption and Decryption using Java.mp4");
59        File file3 = new File("C:\Users\Sohel Rana\Desktop\test\30 - Dank Meme Bro.mp4");
60        File file4 = new File("C:\Users\Sohel Rana\Desktop\test\How to change API level Android Studio.mp4");
61
62        Executor ex = new Executor();
63        long startTime = System.currentTimeMillis();
64        pool.execute(() -> {
65            try {
66                ex.encrypt(file1);
67                ex.encrypt(file2);
68                 ex.encrypt(file3);
69                ex.encrypt(file4);
70            } catch (Exception ex1) {
71                Logger.getLogger(Executor.class.getName()).log(Level.SEVERE, null, ex1);
72            }
73        });
74
75        pool.shutdown();
76
77        if (!pool.awaitTermination(1, TimeUnit.DAYS)) {
78            System.err.println("Pool did not terminate.");
79        }
80                long endTime = System.currentTimeMillis();
81
82        System.out.println("Paralle took time " + (endTime - startTime)
83                + " milliseconds.");
84
85    }
86}