Most viewed questions in Blockchain

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Truffle Compile failing, ParserError: Expected token LParen got Identifier function

Your parentheses are mismatched. pragma solidity ^0.4.17; import "truffle/Assert.sol"; import ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,190 points
1,716 views
0 votes
1 answer

BitcoinJ generate address from private key

Convert string private key into bytes[]: ECKey key = ...READ MORE

Sep 4, 2018 in Blockchain by slayer
• 29,330 points
1,707 views
+1 vote
0 answers

Can't call contract function in Remix in Web3 provider mode, but it works in Javascript VM

A simple contract for addition, an error ...READ MORE

Jun 15, 2019 in Blockchain by XHQ
1,702 views
0 votes
1 answer

Hyperledger Fabric:Promise is rejected:Error:Failed to deserialize creator identity,The supplied identity is not valid.

 This error happens because basic-network/docker-compose.yaml has CA ...READ MORE

Nov 14, 2018 in Blockchain by Omkar
• 69,190 points
1,702 views
0 votes
1 answer

Truffle compile shows DeclarationError: Undeclared identifier.

Hey. You might have missed declaring the "myaddress"  ...READ MORE

Dec 4, 2018 in Blockchain by Omkar
• 69,190 points
1,692 views
0 votes
1 answer

what coding language is this in for ethereum and does this work for trading if setup right?

Hi there, I dont know about ethereum, but ...READ MORE

Jan 4, 2021 in Blockchain by Achuth
• 150 points
1,691 views
+1 vote
3 answers

How to resolve the hyperledger fabric versions set up?

How to simple way to upgrade the ...READ MORE

Dec 18, 2018 in Blockchain by anonymous
1,687 views
+2 votes
2 answers

Can two chaincode interact with each other?

Yes, it is possible for two chaincodes ...READ MORE

Jul 12, 2018 in Blockchain by slayer
• 29,330 points
1,684 views
0 votes
1 answer

How to solve EACCES:permission denied error in Hyperledger Composer?

It seems like there is no required ...READ MORE

Jul 11, 2018 in Blockchain by digger
• 26,740 points
1,684 views
+4 votes
2 answers

I am unable to connect Ganache with Truffle/Npm Dev server. Pls help.

The issue is at CurrentProvider. Give the url ...READ MORE

Mar 26, 2018 in Blockchain by Perry
• 17,100 points

edited Oct 11, 2018 by Omkar 1,681 views
–1 vote
1 answer

How to get balance of all accounts in ethereum network using javascript?

You can write a function that will ...READ MORE

Jan 10, 2019 in Blockchain by Omkar
• 69,190 points
1,676 views
+1 vote
1 answer

How to create participant and there identities via rest API in Hyperledger Composer?

If you have already imported an Identity ...READ MORE

Aug 10, 2018 in Blockchain by Perry
• 17,100 points
1,676 views
0 votes
1 answer

How to Check if string is in list in javascript?

At first, make sure that the string ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,330 points
1,670 views
0 votes
1 answer

Hyperledger Fabric: How to create wallet using program?

You can do this by passing some ...READ MORE

Oct 31, 2018 in Blockchain by Omkar
• 69,190 points
1,659 views
0 votes
1 answer

Hyperledger Fabric :failed to send proposal to peers: Unable to resolve host peer0.org1

This peer address does not exist on ...READ MORE

Nov 16, 2018 in Blockchain by Omkar
• 69,190 points
1,652 views
0 votes
1 answer

Hyperledger Fabric: How to access transaction ID in invoke function?

You can access transaction ID in Invoke ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 69,190 points
1,651 views
0 votes
1 answer

Unable to enroll user in new org

The thing is by default, fabric-ca only has ...READ MORE

Aug 25, 2018 in Blockchain by Christine
• 15,790 points
1,645 views
0 votes
1 answer

How would I run SpringBoot with the Java-SDK of Hyperledger Fabric java daemon?

I am not familiar with SpringBoot, but ...READ MORE

Jul 4, 2018 in Blockchain by aryya
• 7,450 points
1,635 views
0 votes
1 answer

How to create channels in Hyperledger Sawtooth?

There are two features that I know ...READ MORE

Aug 9, 2018 in Blockchain by slayer
• 29,330 points
1,621 views
0 votes
1 answer

Bitcoin Wallet address validation using Json and bitcoin/blockexplorer.

The URL isn't returning JSON. So instead ...READ MORE

Aug 20, 2018 in Blockchain by slayer
• 29,330 points
1,616 views
0 votes
1 answer

How to interact with a Smart Contract on private network using Web3.js?

Once you set up infura you can ...READ MORE

Aug 22, 2018 in Blockchain by Christine
• 15,790 points
1,612 views
0 votes
1 answer

How to join a peer to a channel in Hyperledger Fabric?

When you run the command: peer channel create ...READ MORE

Jul 31, 2018 in Blockchain by digger
• 26,740 points
1,611 views
0 votes
1 answer

How to Query hdfs with Spark Sql

Yyou can achieve this by creating Dataframe. val ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,330 points
1,607 views
0 votes
1 answer

Solidity: How to return id from hash value?

You can do it by storing the hash ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,190 points
1,604 views
0 votes
1 answer

Ethereum smart contract event trigger notification

I have an example here for web3js ...READ MORE

Aug 1, 2018 in Blockchain by slayer
• 29,330 points
1,604 views
+1 vote
3 answers

Pass all .dat files in folder to function

os.listdir(path) return names, not fullpaths change parseBlockFile(file) to fullpath = os.path.join(path,file) if os.path.isfile(fullpath) ...READ MORE

Sep 5, 2018 in Blockchain by Saygum
1,600 views
0 votes
1 answer

Unable to bring up first network in hyperledger fabric

I think there's a conflict with docker ...READ MORE

May 2, 2019 in Blockchain by Karan
1,598 views
0 votes
1 answer

Error using EtherJS: this.provider.getTransactionCount is not a function

With this line it should work fine: wallet.provider ...READ MORE

Sep 26, 2018 in Blockchain by digger
• 26,740 points
1,592 views
0 votes
1 answer

How to read a state after writing it into a chaincode?

Data that is 'written' in chaincode is ...READ MORE

May 28, 2018 in Blockchain by Perry
• 17,100 points
1,585 views
0 votes
1 answer

getting error while starting Hyperleger fabric network on Aws server

Hey, @Nithin, It seems like you have stopped containers ...READ MORE

Mar 30, 2020 in Blockchain by Gitika
• 65,910 points
1,583 views
0 votes
1 answer

truffle compile shows error: TypeError: Invalid type for argument in function call.

You are getting this error because you ...READ MORE

Dec 5, 2018 in Blockchain by Omkar
• 69,190 points
1,572 views
0 votes
2 answers

web3 accounts coming undefined

Try this :  web3.eth.getAccounts() READ MORE

Jul 23, 2020 in Blockchain by Manas
• 150 points
1,561 views
0 votes
1 answer

Test ethereum Event Logs with truffle

You are passing tx hash into done() ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,330 points
1,561 views
0 votes
1 answer

how to develop healthcare records using DApp on Blockchain?

Hi. As Healthcare will be a private ...READ MORE

Jul 26, 2019 in Blockchain by Esha
1,557 views
+1 vote
1 answer

Why is it so difficult to find a nonce while validating a block in Bitcoin?

A nonce is just "some arbitrary number". In ...READ MORE

Apr 11, 2018 in Blockchain by Perry
• 17,100 points
1,557 views
0 votes
1 answer

How to access bitcoin Daemon from other services?

You don't need all these things to ...READ MORE

Aug 29, 2018 in Blockchain by digger
• 26,740 points
1,555 views
0 votes
0 answers

Hyperledger Fabric: Errors in Deliver and Broadcast services

Hello, I have create successfully a multi-org, ...READ MORE

Feb 22, 2019 in Blockchain by Cha
1,548 views
0 votes
1 answer

Truffle dev says my function is not a function

It seems you are using truffle v5. ...READ MORE

Jan 24, 2019 in Blockchain by Omkar
• 69,190 points
1,547 views
0 votes
1 answer

Geth account password on command line

You've got the following two ways to create ...READ MORE

May 29, 2018 in Blockchain by Perry
• 17,100 points
1,542 views
0 votes
1 answer

How to set web3 solidity variable value?

The setLog transaction has not yet been mined by ...READ MORE

Jul 6, 2018 in Blockchain by Christine
• 15,790 points
1,534 views
0 votes
1 answer

Hyperledger-Composer: Error: Object with ID 'undefined' in collection with ID 'chaincodes' does not exist

First delete the cache and cookies from ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 69,190 points
1,530 views
0 votes
1 answer

Not able to install truffle

This error occurs when there are permission ...READ MORE

Jan 29, 2019 in Blockchain by Omkar
• 69,190 points
1,528 views
+1 vote
1 answer

Can we copy a smart contract?

While the contract is open-source, if you ...READ MORE

Apr 7, 2018 in Blockchain by Christine
• 15,790 points
1,528 views
0 votes
1 answer

Web3js: how to catch ethereum contract exception?

try this: try{ Test test = Test.load(contractObj.getContractAddress(), ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 69,190 points
1,515 views
0 votes
1 answer

Hyperledger Fabric: orderer launching fails with error "panic: Error reading configuration:Unsupported Config Type"

The error says there's some problem finding ...READ MORE

Oct 30, 2018 in Blockchain by Omkar
• 69,190 points
1,513 views
+1 vote
1 answer

hyperledger fabric: can't find package: github.com/pkg/errors in GOPATH or GOROOT

Hey @aiga, try to add the package ...READ MORE

Aug 5, 2019 in Blockchain by Esha
1,508 views
0 votes
1 answer

Python Script to pull data from Blockchain JSON

Try this: print r.json()['address'],' has ', r.json()['n_tx'], 'tr ...READ MORE

Sep 14, 2018 in Blockchain by digger
• 26,740 points
1,508 views
0 votes
1 answer

How to create a Genesis Block in a Private Network?

{     "nonce": "0x0000000000000042",     "difficulty": "0x000000100",     "alloc": {     },     "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",     "coinbase": "0x0000000000000000000000000000000000000000",     "timestamp": "0x00",     "parentHash": ...READ MORE

Jul 12, 2018 in Blockchain by digger
• 26,740 points
1,504 views
+2 votes
1 answer

Blockchain declining my API key and I cannot understand why.

It's quite easy. Request the API key using ...READ MORE

Apr 3, 2018 in Blockchain by Christine
• 15,790 points
1,496 views