直接上代码了

python版

源代码

import hashlib as hasher
import datetime as date

class Block:
	def __init__(self, index, timestamp, data, previous_hash):
		self.index = index
		self.timestamp = timestamp
		self.data = data
		self.previous_hash = previous_hash
		self.hash = self.hash_block()

	def hash_block(self):
		sha = hasher.sha256()
		sha.update(str(self.index) +
				   str(self.timestamp) +
				   str(self.data) +
				   str(self.previous_hash))
		return sha.hexdigest()

	def __str__(self):
		output = str(self.index) + "  /  " + \
				 str(self.timestamp) + "  /  " + \
				 str(self.data) + "  /  " + \
				 str(self.previous_hash[:10])
		return output

def create_genesis_block():
	# Manually construct a block with
	# index zero and arbitrary previous hash
	return Block(0, date.datetime.now(), "Awesome Neo", "0")

def next_block(last_block):
	this_index = last_block.index + 1
	this_timestamp = date.datetime.now()
	this_data = "Hello, I am the Neo Coin! Block " + str(this_index)
	previous_hash = last_block.hash
	return Block(this_index, this_timestamp, this_data, previous_hash)

# Create the blockchain and add the genesis block
blockchain = [create_genesis_block()]
previous_block = blockchain[0]

# How many blocks should we add to the chain
# after the genesis block
num_of_blocks_to_add = 10

# Add blocks to the chain
for i in range(0, num_of_blocks_to_add):
	block_to_add = next_block(previous_block)
	blockchain.append(block_to_add)
	previous_block = block_to_add

	# Tell everyone about it 
	print "Neo Coin! Block #{} has been added to the blockchain! ".format(block_to_add.index)
	print block_to_add
	print "Hash: {}\n".format(block_to_add.hash)

执行结果

Neo Coin! Block #1 has been added to the blockchain! 
1  /  2018-06-05 14:05:22.938457  /  Hello, I am the Neo Coin! Block 1  /  a23ae1da4a
Hash: 919166349a83da484959e63a481edbeb7bd9b7b729b095f5f34e2a66c0a300b4

Neo Coin! Block #2 has been added to the blockchain! 
2  /  2018-06-05 14:05:22.938564  /  Hello, I am the Neo Coin! Block 2  /  919166349a
Hash: ca8234e03378206ca75ecdeb9684565b1dbe8b1543cbab8769045e987033e06d

Neo Coin! Block #3 has been added to the blockchain! 
3  /  2018-06-05 14:05:22.938602  /  Hello, I am the Neo Coin! Block 3  /  ca8234e033
Hash: 95d5b5232a9e62ad7586aac312c812ea50f2e5f93d2304ef5775ceeebfef40e6

Neo Coin! Block #4 has been added to the blockchain! 
4  /  2018-06-05 14:05:22.938636  /  Hello, I am the Neo Coin! Block 4  /  95d5b5232a
Hash: b49fb1ec2541f115911668484e390b542b38b1fa404bd1c7cc0acffb2206f204

Neo Coin! Block #5 has been added to the blockchain! 
5  /  2018-06-05 14:05:22.938667  /  Hello, I am the Neo Coin! Block 5  /  b49fb1ec25
Hash: 403d1ff497d5f0a125a79a39027ccdf0a88059a9595fe577313f2014d635288a

Neo Coin! Block #6 has been added to the blockchain! 
6  /  2018-06-05 14:05:22.938698  /  Hello, I am the Neo Coin! Block 6  /  403d1ff497
Hash: 830ae497ab5333c9fe2b728a71d65e7080a622e4caac23b7ad5c26d22751eb7c

Neo Coin! Block #7 has been added to the blockchain! 
7  /  2018-06-05 14:05:22.938731  /  Hello, I am the Neo Coin! Block 7  /  830ae497ab
Hash: 438646e0460004080ee9e82ce0341d1cb83a32c5b39bc1818e43cbddf9d00e37

Neo Coin! Block #8 has been added to the blockchain! 
8  /  2018-06-05 14:05:22.938765  /  Hello, I am the Neo Coin! Block 8  /  438646e046
Hash: 44e4c9bad637a9d588b291a8d6b60c0d8cd32f682b14e8db6488b8c7ccbb5133

Neo Coin! Block #9 has been added to the blockchain! 
9  /  2018-06-05 14:05:22.938798  /  Hello, I am the Neo Coin! Block 9  /  44e4c9bad6
Hash: 8cc2ed10b36346218b3c52a4ed6feb0c292ef3b30f3c46ba58400c7916f03b87

Neo Coin! Block #10 has been added to the blockchain! 
10  /  2018-06-05 14:05:22.938831  /  Hello, I am the Neo Coin! Block 10  /  8cc2ed10b3
Hash: ab64e62c74822b41a2e975f5441787be0d67e309ccc6be44052053418ad08fc4

Java版

源代码

package com.sunrise22.scoin;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Date;

public class ScoinApp {

    private static final int NUM_OF_BLOCKS_TO_ADD = 10;

    private static ScoinInnerBlock[] ScoinInnerBlockChain = new ScoinInnerBlock[NUM_OF_BLOCKS_TO_ADD];

    public static void main(String[] args) {
        ScoinInnerBlock genesisBlock = createGenesisBlock();
        ScoinInnerBlockChain[0] = genesisBlock;
        ScoinInnerBlock lastBlock = genesisBlock;

        for (int i = 1; i < NUM_OF_BLOCKS_TO_ADD; i++) {
            ScoinInnerBlock current = nextBlock(lastBlock);
            ScoinInnerBlockChain[i] = current;

            System.out.println("S Coin! Block #{" + current.getIndex() + "} has been added to the chain!");
            System.out.println(current);
            System.out.println("Hash: " + current.getHash());
            System.out.println("========================================================================");
            lastBlock = current;
        }
    }

    public static ScoinInnerBlock createGenesisBlock() {
        Date date = new Date();
        return new ScoinInnerBlock(0, date.toString(), "Slience is gold!", ".notatall.");
    }

    public static ScoinInnerBlock nextBlock(ScoinInnerBlock lastBlock) {
        int thisIndex = lastBlock.getIndex() + 1;
        String thisData = "Hello, I am the S coin! Block " + thisIndex;
        String prevHash = lastBlock.getHash();
        Date date = new Date();
        return new ScoinInnerBlock(thisIndex, date.toString(), thisData, prevHash);
    }
}

class ScoinInnerBlock {

    public int getIndex() {
        return index;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public String getData() {
        return data;
    }

    public String getPreviousHash() {
        return previousHash;
    }

    public String getHash() {
        return hash;
    }

    private int index;
    private String timestamp;
    private String data;
    private String previousHash;
    private String hash;

    public ScoinInnerBlock(int index, String timestamp, String data, String previousHash) {
        super();
        this.index = index;
        this.timestamp = timestamp;
        this.data = data;
        this.previousHash = previousHash;
        this.hash = hashBlock();
    }

    public String hashBlock() {
        String src = this.index + this.timestamp + this.data + this.previousHash;
        String sha = getSHA256StrJava(src);
        return sha;
    }

    @Override
    public String toString() {
        return "ScoinInnerBlock [index=" + index + ", timestamp=" + timestamp + ", data=" + data + ", previousHash="
                + previousHash + ", hash=" + hash + "]";
    }

    /**
     * 利用java原生的摘要实现SHA256加密 <br >
     * 
     * @param str
     *            加密后的报文<br>
     * @return
     */
    public static String getSHA256StrJava(String str) {
        MessageDigest messageDigest;
        String encodeStr = "";
        try {
            messageDigest = MessageDigest.getInstance("SHA-256");
            messageDigest.update(str.getBytes("UTF-8"));
            encodeStr = byte2Hex(messageDigest.digest());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return encodeStr;
    }

    /**
     * 将byte转为16进制 @param bytes @return
     */

    private static String byte2Hex(byte[] bytes) {
        StringBuffer stringBuffer = new StringBuffer();
        String temp = null;
        for (int i = 0; i < bytes.length; i++) {
            temp = Integer.toHexString(bytes[i] & 0xFF);
            if (temp.length() == 1) {
                // 1得到一位的进行补0操作
                stringBuffer.append("0");
            }
            stringBuffer.append(temp);
        }
        return stringBuffer.toString();
    }
}

执行结果

S Coin! Block #{1} has been added to the chain!
ScoinInnerBlock [index=1, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 1, previousHash=569f8523cafcaec1b1dbf7000f327dee5ecb7a73b0d2506c6aa229e5f0a07d29, hash=fc3670cead47ea0333f6d02ac499db3d1de19dbef8d0aef67e36efb29eccdbae]
Hash: fc3670cead47ea0333f6d02ac499db3d1de19dbef8d0aef67e36efb29eccdbae
========================================================================
S Coin! Block #{2} has been added to the chain!
ScoinInnerBlock [index=2, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 2, previousHash=fc3670cead47ea0333f6d02ac499db3d1de19dbef8d0aef67e36efb29eccdbae, hash=5965c78ba7bc96ca42904c5dfa4cc921dde723fd79d0ca38764bd16ec0cf66c0]
Hash: 5965c78ba7bc96ca42904c5dfa4cc921dde723fd79d0ca38764bd16ec0cf66c0
========================================================================
S Coin! Block #{3} has been added to the chain!
ScoinInnerBlock [index=3, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 3, previousHash=5965c78ba7bc96ca42904c5dfa4cc921dde723fd79d0ca38764bd16ec0cf66c0, hash=aff024d47d2206131eaf2cd5afe5cb5714e9c33f1cd8efc689cbe821d539c094]
Hash: aff024d47d2206131eaf2cd5afe5cb5714e9c33f1cd8efc689cbe821d539c094
========================================================================
S Coin! Block #{4} has been added to the chain!
ScoinInnerBlock [index=4, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 4, previousHash=aff024d47d2206131eaf2cd5afe5cb5714e9c33f1cd8efc689cbe821d539c094, hash=0315235bc031d4adc14ffab795d19f718a057975f82c2cf54d5c661fc8325307]
Hash: 0315235bc031d4adc14ffab795d19f718a057975f82c2cf54d5c661fc8325307
========================================================================
S Coin! Block #{5} has been added to the chain!
ScoinInnerBlock [index=5, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 5, previousHash=0315235bc031d4adc14ffab795d19f718a057975f82c2cf54d5c661fc8325307, hash=25e6a78026ac58bee367d416eee161928a92bc61fc82eba7ca31719070acc5b1]
Hash: 25e6a78026ac58bee367d416eee161928a92bc61fc82eba7ca31719070acc5b1
========================================================================
S Coin! Block #{6} has been added to the chain!
ScoinInnerBlock [index=6, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 6, previousHash=25e6a78026ac58bee367d416eee161928a92bc61fc82eba7ca31719070acc5b1, hash=ac47547ffe54e1dc046a291341a1f6ebeb3017cec22c7fbcfee2ef2babb14997]
Hash: ac47547ffe54e1dc046a291341a1f6ebeb3017cec22c7fbcfee2ef2babb14997
========================================================================
S Coin! Block #{7} has been added to the chain!
ScoinInnerBlock [index=7, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 7, previousHash=ac47547ffe54e1dc046a291341a1f6ebeb3017cec22c7fbcfee2ef2babb14997, hash=10de0891e7168454add7ea9920e06667de8c296b84716fcb884785a1ac600765]
Hash: 10de0891e7168454add7ea9920e06667de8c296b84716fcb884785a1ac600765
========================================================================
S Coin! Block #{8} has been added to the chain!
ScoinInnerBlock [index=8, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 8, previousHash=10de0891e7168454add7ea9920e06667de8c296b84716fcb884785a1ac600765, hash=37d046e4cc58590fe7ea5896b6fa9b14250f0e9a2c9ccfda067b6cfc91cbfc93]
Hash: 37d046e4cc58590fe7ea5896b6fa9b14250f0e9a2c9ccfda067b6cfc91cbfc93
========================================================================
S Coin! Block #{9} has been added to the chain!
ScoinInnerBlock [index=9, timestamp=Tue Jun 05 14:15:37 CST 2018, data=Hello, I am the S coin! Block 9, previousHash=37d046e4cc58590fe7ea5896b6fa9b14250f0e9a2c9ccfda067b6cfc91cbfc93, hash=192571b98481619a959488817554bc82abada702d2629c55fc8a734b2cbd7917]
Hash: 192571b98481619a959488817554bc82abada702d2629c55fc8a734b2cbd7917
========================================================================