区块链 × GoLang：后端开发的创新组合

package main

import (
    "crypto/sha256"
    "encoding/hex"
    "encoding/json"
    "fmt"
    "log"
    "time"
)

type Block struct {
    Index        int
    Timestamp    time.Time
    Data         string
    PreviousHash string
    Hash         string
}

var Blockchain []Block

func main() {
    // 创建创世区块
    genesisBlock := createGenesisBlock()
    Blockchain = append(Blockchain, genesisBlock)

    // 添加新块
    newBlock := createBlock("Block 1")
    Blockchain = append(Blockchain, newBlock)

    // 验证区块链
    if isBlockchainValid(Blockchain) {
        log.Println("区块链有效!")
    }
}

// 创建创世区块
func createGenesisBlock() Block {
    return Block{
        Index:        0,
        Timestamp:    time.Now(),
        Data:         "Genesis Block",
        PreviousHash: "",
        Hash:         calculateHash(0, "", "Genesis Block", ""),
    }
}

// 创建新块
func createBlock(data string) Block {
    previousBlock := Blockchain[len(Blockchain)-1]
    block := Block{
        Index:        previousBlock.Index + 1,
        Timestamp:    time.Now(),
        Data:         data,
        PreviousHash: previousBlock.Hash,
        Hash:         calculateHash(previousBlock.Index+1, previousBlock.Hash, data, ""),
    }
    return block
}

// 计算哈希值
func calculateHash(index int, previousHash string, data string, nonce string) string {
    blockData := fmt.Sprintf("%d%s%s%s", index, previousHash, data, nonce)
    hash := sha256.Sum256([]byte(blockData))
    return hex.EncodeToString(hash[:])
}

// 验证区块链的完整性
func isBlockchainValid(blocks []Block) bool {
    for i := 1; i < len(blocks); i++ {
        block := blocks[i]
        previousBlock := blocks[i-1]

        // 验证哈希值
        if block.Hash != calculateHash(block.Index, block.PreviousHash, block.Data, "") {
            log.Println("无效的区块哈希值:", block.Index)
            return false
        }

        // 验证前一哈希值
        if block.PreviousHash != previousBlock.Hash {
            log.Println("无效的前一区块哈希值:", block.Index)
            return false
        }
    }

    return true
}