-
Notifications
You must be signed in to change notification settings - Fork 2
/
Block.java
58 lines (45 loc) · 1.69 KB
/
Block.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
import java.util.Date;
import java.security.MessageDigest;
public class Block extends time_encrypto{
public String hash;
public String previousHash;
private String data;
private String timeStamp;
private int nonce;
public Block(String data, String previousHash){
this.data = data;
this.previousHash = previousHash;
this.timeStamp = time_encrypto.gettime();
this.hash = calculateHash();
System.out.println("String for blocks : " + data + previousHash + timeStamp);
}
public String calculateHash(){
String calculatedhash = applySha256( previousHash + timeStamp + Integer.toString(nonce) + data );
return calculatedhash;
}
public void mineBlock(int difficulty) {
String target = new String(new char[difficulty]).replace('\0', '0'); //Create a string with difficulty * "0"
while(!hash.substring( 0, difficulty).equals(target)) {
nonce ++;
hash = calculateHash();
}
System.out.println("Block Mined!!! : " + hash);
}
public static String applySha256(String input){
try{
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hash = digest.digest(input.getBytes("UTF-8"));
StringBuffer hexString = new StringBuffer();
for(int i = 0; i < hash.length; i++){
String Hex = Integer.toHexString(0xff & hash[i]);
if(Hex.length() == 1)
hexString.append('0');
hexString.append(Hex);
}
return hexString.toString();
}
catch(Exception e){
throw new RuntimeException(e);
}
}
}