SpringBoot区块链之以太坊区块高度扫描（简洁版）

继续昨天的demo往下写写：SpringBoot区块链之以太坊开发（整合Web3j）,将复杂的逻辑都去除了，留下最简单区块高度扫描部分代码，这样更好让开发者上手首先自定义个区块高度处理线程类

package com.xiaobin.ethdemo.component;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.core.methods.response.EthBlockNumber;

/**
 * 创建时间： 2019/9/24  23:08
 * 备注：
 * 码农自学交流小群：260532022，欢迎大家的加入，分享学习是一件开心事
 **/

@Component
public class EthWatcher implements Runnable {

    @Autowired
    private Web3j web3j;
    // 是否停止扫描
    private boolean stop = false;
    // 当前区块高度
    private Long currentBlockHeight = 8612532L;
    // 等待扫描事件
    private Long checkInterval = 5000L;
    //区块确认数
    private int confirmation = 1;
    // 每次扫描区块的数量
    private int step = 5;

    public void check() {
        try {
            Long networkBlockNumber = getNetworkBlockHeight() - confirmation   1;
            System.out.println(networkBlockNumber);
            currentBlockHeight = (networkBlockNumber - currentBlockHeight > step) ? currentBlockHeight   step : networkBlockNumber;
            System.out.println("扫描当前区块高度：" currentBlockHeight);
            System.out.println("当前网络区块高度：" networkBlockNumber);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        stop = false;
        long nextCheck = 0;
        while (!(Thread.interrupted() || stop)) {
            if (nextCheck <= System.currentTimeMillis()) {
                try {
                    nextCheck = System.currentTimeMillis()   checkInterval;
                    check();
                } catch (Exception ex) {

                }
            } else {
                try {
                    Thread.sleep(Math.max(nextCheck - System.currentTimeMillis(), 100));
                } catch (InterruptedException ex) {

                }
            }
        }
    }


    public Long getNetworkBlockHeight() {
        try {
            EthBlockNumber blockNumber = web3j.ethBlockNumber().send();
            return blockNumber.getBlockNumber().longValue();
        } catch (Exception e) {
            e.printStackTrace();
            return 0L;
        }
    }
}

然后启动就ok拉,我这里使用的使用@PostConstruct注解，也可以在Spring容器加载时启动，都可以的

 @Autowired
    private EthWatcher ethWatcher;

    @PostConstruct
    public void start(){
        new Thread(ethWatcher).start();
    }

效果图

我们可以通过区块高度获取到每笔交易的详情信息，然后进行处理，这里的逻辑就需要自己写拉，Get请求例子例子

@GetMapping("/test")
    public List test() throws  Exception{
        List list = new ArrayList<>();
        EthBlockNumber blockNumber = web3j.ethBlockNumber().send();
        long blockHeight = blockNumber.getBlockNumber().longValue();
        EthBlock block = web3j.ethGetBlockByNumber(new DefaultBlockParameterNumber(blockHeight), true).send();

        block.getBlock().getTransactions().stream().forEach(transactionResult -> {
            EthBlock.TransactionObject transactionObject = (EthBlock.TransactionObject) transactionResult;
            Transaction transaction = transactionObject.get();
            list.add(transaction);
        });
        return list;
    }

效果图码云地址：https://gitee.com/MyXiaoXiaoBin/learning-to-share/tree/master/eth-demo

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