web3.js 是一个通过RPC 调用 和本地以太坊节点进行通信的js库。web3.js可以与任何暴露了RPC接口的以太坊节点连接。 web3中提供了eth对象 - web3.eth来与以太坊区块链进行交互。
安装
npm: npm install web3
bower: bower install web3
metor: meteor add ethereum:web3
vanilla: dist./web3.min.js
获得web3实例
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}
web3.eth.accounts.create();
> {
address: "0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01",
privateKey: "0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709",
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
web3.eth.accounts.create('2435@#@#@±±±±!!!!678543213456764321§34567543213456785432134567');
> {
address: "0xF2CD2AA0c7926743B1D4310b2BC984a0a453c3d4",
privateKey: "0xd7325de5c2c1cf0009fac77d3d04a9c004b038883446b065871bc3e831dcd098",
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
web3.eth.accounts.create(web3.utils.randomHex(32));
> {
address: "0xe78150FaCD36E8EB00291e251424a0515AA1FF05",
privateKey: "0xcc505ee6067fba3f6fc2050643379e190e087aeffe5d958ab9f2f3ed3800fa4e",
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
web3.eth.accounts.privateKeyToAccount(privateKey);
web3.eth.accounts.privateKeyToAccount('0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709');
> {
address: '0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01',
privateKey: '0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709',
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
web3.eth.accounts.privateKeyToAccount('0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709');
> {
address: '0xb8CE9ab6943e0eCED004cDe8e3bBed6568B2Fa01',
privateKey: '0x348ce564d427a3311b6536bbcff9390d69395b06ed6c486954e971d960fe8709',
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
web3.eth.accounts.signTransaction(tx, privateKey [, callback]);
web3.eth.accounts.signTransaction({
to: '0xF0109fC8DF283027b6285cc889F5aA624EaC1F55',
value: '1000000000',
gas: 2000000
}, '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318')
.then(console.log);
> {
messageHash: '0x88cfbd7e51c7a40540b233cf68b62ad1df3e92462f1c6018d6d67eae0f3b08f5',
v: '0x25',
r: '0xc9cf86333bcb065d140032ecaab5d9281bde80f21b9687b3e94161de42d51895',
s: '0x727a108a0b8d101465414033c3f705a9c7b826e596766046ee1183dbc8aeaa68',
rawTransaction: '0xf869808504e3b29200831e848094f0109fc8df283027b6285cc889f5aa624eac1f55843b9aca008025a0c9cf86333bcb065d140032ecaab5d9281bde80f21b9687b3e94161de42d51895a0727a108a0b8d101465414033c3f705a9c7b826e596766046ee1183dbc8aeaa68'
}
web3.eth.accounts.signTransaction({
to: '0xF0109fC8DF283027b6285cc889F5aA624EaC1F55',
value: '1000000000',
gas: 2000000,
gasPrice: '234567897654321',
nonce: 0,
chainId: 1
}, '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318')
.then(console.log);
> {
messageHash: '0x6893a6ee8df79b0f5d64a180cd1ef35d030f3e296a5361cf04d02ce720d32ec5',
r: '0x9ebb6ca057a0535d6186462bc0b465b561c94a295bdb0621fc19208ab149a9c',
s: '0x440ffd775ce91a833ab410777204d5341a6f9fa91216a6f3ee2c051fea6a0428',
v: '0x25',
rawTransaction: '0xf86a8086d55698372431831e848094f0109fc8df283027b6285cc889f5aa624eac1f55843b9aca008025a009ebb6ca057a0535d6186462bc0b465b561c94a295bdb0621fc19208ab149a9ca0440ffd775ce91a833ab410777204d5341a6f9fa91216a6f3ee2c051fea6a0428'
}
web3.eth.accounts.hashMessage(message);
web3.eth.accounts.hashMessage("Hello World")
> "0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2"
// the below results in the same hash
web3.eth.accounts.hashMessage(web3.utils.utf8ToHex("Hello World"))
> "0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2"
web3.eth.accounts.sign(data, privateKey);
web3.eth.accounts.sign('Some data', '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318');
> {
message: 'Some data',
messageHash: '0x1da44b586eb0729ff70a73c326926f6ed5a25f5b056e7f47fbc6e58d86871655',
v: '0x1c',
r: '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd',
s: '0x6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a029',
signature: '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a0291c'
}
传入私钥和密码
web3.eth.accounts.encrypt('0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318', 'test!')
> {
version: 3,
id: '04e9bcbb-96fa-497b-94d1-14df4cd20af6',
address: '2c7536e3605d9c16a7a3d7b1898e529396a65c23',
crypto: {
ciphertext: 'a1c25da3ecde4e6a24f3697251dd15d6208520efc84ad97397e906e6df24d251',
cipherparams: { iv: '2885df2b63f7ef247d753c82fa20038a' },
cipher: 'aes-128-ctr',
kdf: 'scrypt',
kdfparams: {
dklen: 32,
salt: '4531b3c174cc3ff32a6a7a85d6761b410db674807b2d216d022318ceee50be10',
n: 262144,
r: 8,
p: 1
},
mac: 'b8b010fff37f9ae5559a352a185e86f9b9c1d7f7a9f1bd4e82a5dd35468fc7f6'
}
}
web3.eth.accounts.decrypt({
version: 3,
id: '04e9bcbb-96fa-497b-94d1-14df4cd20af6',
address: '2c7536e3605d9c16a7a3d7b1898e529396a65c23',
crypto: {
ciphertext: 'a1c25da3ecde4e6a24f3697251dd15d6208520efc84ad97397e906e6df24d251',
cipherparams: { iv: '2885df2b63f7ef247d753c82fa20038a' },
cipher: 'aes-128-ctr',
kdf: 'scrypt',
kdfparams: {
dklen: 32,
salt: '4531b3c174cc3ff32a6a7a85d6761b410db674807b2d216d022318ceee50be10',
n: 262144,
r: 8,
p: 1
},
mac: 'b8b010fff37f9ae5559a352a185e86f9b9c1d7f7a9f1bd4e82a5dd35468fc7f6'
}
}, 'test!');
> {
address: "0x2c7536E3605D9C16a7a3D7b1898e529396a65c23",
privateKey: "0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318",
signTransaction: function(tx){...},
sign: function(data){...},
encrypt: function(password){...}
}
eb3.eth.accounts.wallet;
web3.eth.accounts.wallet;
> Wallet {
0: {...}, // account by index
"0xF0109fC8DF283027b6285cc889F5aA624EaC1F55": {...}, // same account by address
"0xf0109fc8df283027b6285cc889f5aa624eac1f55": {...}, // same account by address lowercase
1: {...},
"0xD0122fC8DF283027b6285cc889F5aA624EaC1d23": {...},
"0xd0122fc8df283027b6285cc889f5aa624eac1d23": {...},
add: function(){},
remove: function(){},
save: function(){},
load: function(){},
clear: function(){},
length: 2,
}
web3.eth.personal.newAccount(password, [callback])
web3.eth.personal.newAccount('!@superpassword')
.then(console.log);
> '0x1234567891011121314151617181920212223456'
web3.eth.getBalance('0xe70c4835b29e2fd35bd3f60c0a76413f70f17115').then(function(balance){
console.log('balance:',balance)
balance = new BigNumber(balance)
console.log('balance:',balance)
})
这里使用了BigNumber.js 处理余额显示，参考我另一片博文。
#####web3.utils.toHex 将任何值转为HEX 16进制 String|Number|Object|Array|BigNumber - 需要转化为HEX的值。如果是一个对象或数组类型，将会先用JSON.stringify1进行转换成字符串。如果传入的是BigNumber2，则将得到对应的Number的HEX
var str = "abcABC";
var obj = {abc: 'ABC'};
var bignumber = new BigNumber('12345678901234567890');
var hstr = web3.utils.toHex(str);
var hobj = web3.utils.toHex(obj);
var hbg = web3.utils.toHex(bignumber);
console.log("Hex of Sring:" + hstr);
console.log("Hex of Object:" + hobj);
console.log("Hex of BigNumber:" + hbg);
web3.utils.isHex('0xc1912');
web3.utils.isAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');
web3.utils.toWei(number [, unit])
web3.utils.toWei('1', 'ether');
> "1000000000000000000"
web3.utils.toWei('1', 'finney');
> "1000000000000000"
web3.utils.toWei('1', 'szabo');
> "1000000000000"
web3.utils.toWei('1', 'shannon');
/> "1000000000"
web3.utils.fromWei(number [, unit])
web3.utils.fromWei('1', 'ether');
> "0.000000000000000001"
web3.utils.fromWei('1', 'finney');
> "0.000000000000001"
web3.utils.fromWei('1', 'szabo');
> "0.000000000001"
web3.utils.fromWei('1', 'shannon');
> "0.000000001"
web3.utils.isBigNumber(bignumber)
var number = new BigNumber(10);
web3.utils.isBigNumber(number);
// web3.utils.sha3(string) // web3.utils.keccak256(string) // ALIAS
web3.utils.sha3('234'); // taken as string
> "0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79"
web3.utils.sha3(new BN('234'));
> "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a"
web3.utils.sha3(234);
> null // can't calculate the has of a number
web3.utils.sha3(0xea); // same as above, just the HEX representation of the number
> null
web3.utils.sha3('0xea'); // will be converted to a byte array first, and then hashed
> "0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a"