Example of AES secret key generation algorithm implemented by java

The example of this paper describes the AES secret key generation algorithm implemented by java. I will share it with you for your reference as follows:

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
public class Test {
  public static void main(String[] args) {
    getKey();
    getKeyByPass();
  }
  /**
  *  Generate the secret key at random 
  */
  public static void getKey() {
    try {
      KeyGenerator kg = KeyGenerator.getInstance("AES");
      kg.init(128);
      // How many bits do I need to generate? I just need to change this 128, 192 or 256
      SecretKey sk = kg.generateKey();
      byte[] b = sk.getEncoded();
      String s = byteToHexString(b);
      System.out.println(s);
      System.out.println("106 The base key length is "+s.length());
      System.out.println("2 The length of the base key is "+s.length()*4);
    }
    catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
      System.out.println(" There is no such algorithm. ");
    }
  }
  /**
  *  Generates the secret key using the specified string 
  */
  public static void getKeyByPass() {
    // To generate the secret key 
    String password="testkey";
    try {
      KeyGenerator kg = KeyGenerator.getInstance("AES");
      // kg.init(128);// How many bits do I need to generate? I just need to change this 128, 192 or 256
      //SecureRandom Is to generate a sequence of safe random Numbers, password.getBytes() Is the seed, as long as the seed is the same, the sequence 1 So the generated secret key is 1 The sample. 
      kg.init(128, new SecureRandom(password.getBytes()));
      SecretKey sk = kg.generateKey();
      byte[] b = sk.getEncoded();
      String s = byteToHexString(b);
      System.out.println(s);
      System.out.println("106 The base key length is "+s.length());
      System.out.println("2 The length of the base key is "+s.length()*4);
    }
    catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
      System.out.println(" There is no such algorithm. ");
    }
  }
  /**
  * byte Array to 16 Base string 
  * @param bytes
  * @return
  */
  public static String byteToHexString(byte[] bytes) {
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < bytes.length; i++) {
      String strHex=Integer.toHexString(bytes[i]);
      if(strHex.length() > 3) {
        sb.append(strHex.substring(6));
      } else {
        if(strHex.length() < 2) {
          sb.append("0" + strHex);
        } else {
          sb.append(strHex);
        }
      }
    }
    return sb.toString();
  }
}

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Password security online detection:
http://tools.ofstack.com/password/my_password_safe

High strength password generator:
http://tools.ofstack.com/password/CreateStrongPassword

Thunderbolt, express, and whirlwind encryption/decryption tools:
http://tools.ofstack.com/password/urlrethunder

Online hash/hash algorithm encryption tool:
http://tools.ofstack.com/password/hash_encrypt

MD5/hash/ SHA-1 / SHA-2 / SHA-256 / SHA-512 / SHA-3 / RIPEMD-160 encryption tools:
http://tools.ofstack.com/password/hash_md5_sha

Online sha1 sha224 / sha256 sha384 / sha512 encryption tools:
http://tools.ofstack.com/password/sha_encode

I hope this article is helpful to you java programming.