web3.js¶

连接到以太坊客户端:

1. http 方式
var Web3 = require('web3');
var web3 = new Web3('http://localhost:8545');

2. WebSocket 方式

var Web3 = require('web3');
var web3 = new Web3(Web3.givenProvider || 'ws://remotenode.com:8546');

3. IPC 方式

// Using the IPC provider in node.js
var net = require('net');
var Web3 = require('web3');
var web3 = new Web3('/Users/myuser/Library/Ethereum/geth.ipc', net); // mac os path

查看账号列表:

var Web3 = require('web3');
var web3 = new Web3('http://localhost:8545');
web3.eth.getAccounts().then(console.log);

查询矿工账号:

var Web3 = require('web3');
var web3 = new Web3('http://localhost:8545');
web3.eth.getCoinbase().then(console.log);

// Callback 方式
web3.eth.getCoinbase(
    function(error, result){
    if (error) {
        console.error(error);
    } else {
        console.log(result);
    }
 })

获得余额:

web3.eth.getBalance(req.query.address).then(function(balance){
      res.json({"status": true, "code":0, "data":{"account":req.query.address, "balance": web3.utils.fromWei(balance)}});
});
// Callback 方式
web3.eth.getBalance(req.query.address, function (error, wei) {
    if (!error) {
        var balance = web3.utils.fromWei(wei, 'ether');
        res.json({"status": true, "code":0, "data":{"account":req.query.address, "balance": balance}});
    }else{
        console.log(error);
        res.json({"status": false, "code":1, "data":{"error":error.message}});
    }
});
// 捕捉错误
router.get('/balance.json', function(req, res) {
  try {
    web3.eth.getBalance(req.query.address, function (error, wei) {
        if (!error) {
            var balance = web3.utils.fromWei(wei, 'ether');
            res.json({"status": true, "code":0, "data":{"account":req.query.address, "balance": balance}});
        }else{
            console.log(error);
            res.json({"status": false, "code":1, "data":{"error":error.message}})
         }
    });
  }
  catch(error){
    res.json({"status": false, "code":1, "data":{"error":error.message}});
  };

});

web3.eth.sendTransaction():

web3.eth.sendTransaction({
      from: coinbase,
      to: '0x2C687bfF93677D69bd20808a36E4BC2999B4767C',
      value: web3.utils.toWei('2','ether')
  },
  function(error, result){
      if(!error) {
          console.log("#" + result + "#")
      } else {
          console.error(error);
      }
});

var code = "0x603d80600c6000396000f3007c01000000000000000000000000000000000000000000000000000000006000350463c6888fa18114602d57005b6007600435028060005260206000f3";

web3.eth.sendTransaction({from: coinbase, data: code}, function(err, transactionHash) {
  if (!err)
    console.log(transactionHash); // "0x7f9fade1c0d57a7af66ab4ead7c2eb7b11a91385"
});

web3.eth.sendTransaction({from: coinbase, data: code}).then(function(receipt){
        console.log(receipt);
});

web3.eth.sendSignedTransaction() 私钥签名转账:

例子1:
var account = web3.eth.accounts.privateKeyToAccount(privateKey);

web3.eth.accounts.signTransaction({
    from: account.address,
    to: "0x0013a861865d74b13ba94713d4e84d97c57e7081",
    gas: "3000000",
    value: '100000000000000000',
    gasPrice: '0x09184e72a000',
    data: "0x00"
  }, account.privateKey)
.then(function(result) {
  console.log("Results: ", result)

  web3.eth.sendSignedTransaction(result.rawTransaction)
    .on('receipt', console.log);
})

fs = require('fs');
const Web3 = require('web3');
var Tx = require('ethereumjs-tx');
const web3 = new Web3('http://localhost:8545');
console.log(web3.version)

coinbase  = "0xaa96686a050e4916afbe9f6d8c5107062fa646dd";
address   = "0x372fda02e8a1eca513f2ee5901dc55b8b5dd7411"
contractAddress = "0x9ABcF16f6685fE1F79168534b1D30056c90B8A8A"

const main = async () => {
  var balance = await web3.eth.getBalance(coinbase);
  console.log(`Balance ETH: ${balance} \n`);

  const abi = fs.readFileSync('output/NetkillerToken.abi', 'utf-8');
  const contract = new web3.eth.Contract(JSON.parse(abi), contractAddress, { from: address});

  var balance = await contract.methods.balanceOf(address).call();
  console.log(`Balance before send: ${balance} \n`);

  var count = await web3.eth.getTransactionCount(coinbase);
  const gasPrice = await web3.eth.getGasPrice();
  console.log(`gasPrice: ${gasPrice}\n`)
      var gasLimit = 1000000;
  var transferAmount = 1000;
    // Chain ID of Ropsten Test Net is 3, replace it to 1 for Main Net
    var chainId = 1;

    var rawTransaction = {
        "from": coinbase,
        /* "nonce": "0x" + count.toString(16),*/
        "nonce":  web3.utils.toHex(count),
        "gasPrice": web3.utils.toHex(gasPrice),
        "gasLimit": web3.utils.toHex(gasLimit),
        "to": contractAddress,
        "value": "0x0",
        "data": contract.methods.transfer(address, transferAmount).encodeABI(),
        "chainId": web3.utils.toHex(chainId)
    };

    console.log(`Raw of Transaction: \n${JSON.stringify(rawTransaction, null, '\t')}\n`);

    // The private key for myAddress in .env
    var privateKey = new Buffer(process.env["PRIVATE_KEY"], 'hex');
    var tx = new Tx(rawTransaction);
    tx.sign(privateKey);
    var serializedTx = tx.serialize();

    // Comment out these four lines if you don't really want to send the TX right now
    console.log(`Attempting to send signed tx:  ${serializedTx.toString('hex')}\n`);

    var receipt = await web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex'));

    // The receipt info of transaction, Uncomment for debug
    console.log(`Receipt info: \n${JSON.stringify(receipt, null, '\t')}\n`);

    // The balance may not be updated yet, but let's check
  var balance = await contract.methods.balanceOf(address).call();
  console.log(`Balance after send: ${balance}`);
}

main();

web3.eth.getBlock() 获取区块:

// 获取 pending 状态的区块
web3.eth.getBlock(
    "pending",
function (error, block) {
    if (error) {
        console.error(error);
    } else {
        console.log(block.transactions.length);
    }
});

账号管理:

  var coinbase = "0x5c18a33DF2cc41a1bedDC91133b8422e89f041B7";
  //console.log(coinbase)
  web3.eth.personal.unlockAccount(coinbase, "your password").then(console.log);




// 查询默认帐户余额
> web3.fromWei(eth.getBalance(eth.coinbase), "ether")
// 查询第2个帐户余额
web3.fromWei(eth.getBalance(eth.accounts[1]),"ether")