eth交易

 　　//获取链上最高块
    public long blockNumHight() throws IOException {
        return web3j.ethBlockNumber().send().getBlockNumber().longValue();
    }
    
　　 //获取gas
    public BigInteger getGasPrice() throws Exception {
        return web3j.ethGasPrice().send().getGasPrice();
    }
    
    //根据块号获取eth块信息
    public EthBlock getBlock(long blockNum) throws IOException {
        return EthBlock.fromWeb3( //这里只是把块信息做了一个对象转换
            web3j.ethGetBlockByNumber(new DefaultBlockParameterNumber(blockNum), true).send().getBlock()
        );
    }
    
　　　//根据块哈希获取eth块信息
    public EthBlock getBlock(String blockHash) throws Exception {
        if(StringUtils.isBlank(blockHash)) {
            return null;
        }
        return EthBlock.fromWeb3(
            web3j.ethGetBlockByHash(blockHash, true).send().getBlock()
        );
    }
    
    //根据交易哈希获取eth交易信息
    public Transaction getTransaction(String txHash) throws IOException {
        if(StringUtils.isBlank(txHash)) {
            return null;
        }
        return web3j.ethGetTransactionByHash(txHash).send().getResult();
    }
    
    //根据地址获取nonce
    public BigInteger getNonce(String address) throws IOException{
        return web3j.ethGetTransactionCount(address.toLowerCase(), DefaultBlockParameterName.PENDING).send().getTransactionCount();
    }
    
    //获取地址的余额
    public BigInteger getBalance(String address) throws IOException {
        String checkedAddr = EthUtils.checkAddress(address);
        if(StringUtils.isBlank(checkedAddr)) {
            return BigInteger.ZERO;
        }
        return web3j.ethGetBalance(address, DefaultBlockParameterName.PENDING).send().getBalance();
    }

    //获取某一块上的地址的余额
    public BigInteger getBalance(String address, long blockNum) throws IOException {
        String checkedAddr = EthUtils.checkAddress(address);
        if(StringUtils.isBlank(checkedAddr)) {
            return BigInteger.ZERO;
        }
        return web3j.ethGetBalance(address, new DefaultBlockParameterNumber(blockNum)).send().getBalance();
    }
    
    //发eth交易
    public SendTransaction transfer(
            String sourceAddr, String sourcePriKey, String targetAddr, BigInteger amount, BigInteger gasPrice, boolean amountIncludeFee) throws Exception {
        sourceAddr = EthUtils.checkAddress(sourceAddr);
        targetAddr = EthUtils.checkAddress(targetAddr);
        if(StringUtils.isAnyBlank(sourceAddr,targetAddr,sourcePriKey)) {
            return null;
        }
        if(gasPrice==null || gasPrice.compareTo(BigInteger.ZERO)<0 
                || amount==null || amount.compareTo(BigInteger.ZERO)<0 
        ) {
            return null;
        }
        BigInteger gas = EthUtils.calculateGas(null, gasPrice);
        BigInteger payAmount = amount;
        if(amountIncludeFee) {
            payAmount = amount.subtract(gas);
            if(payAmount.compareTo(BigInteger.ZERO)<0) {
                return null;
            }
        }
        //检查余额
        BigInteger balance = this.getBalance(sourceAddr);
        if(balance.compareTo(payAmount.add(gas)) < 0) {
            return null;
        }
        BigInteger nonce = this.getNonce(sourceAddr);
        String txHexData = EthUtils.signTransaction(sourceAddr, sourcePriKey, nonce, targetAddr, gasPrice, payAmount, null);
        if(StringUtils.isBlank(txHexData)) {
            return null;
        }
        EthSendTransaction ethSendTransaction = web3j.ethSendRawTransaction(txHexData).send();
        return new SendTransaction(ethSendTransaction.getTransactionHash(), nonce, Convert.fromWei(gas.toString(), Unit.ETHER));
    }