Questions tagged [java]

Java is a programming language.

32 questions with no upvoted or accepted answers
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votes
1answer
441 views

How to build Merkle root from merkle branches?

Is there any help/tutorial on how to build the Merkle root from stratum data? The Slushpool's stratum protocol has an example of a mining job but it does not contain any Merkle branches and I don't ...
5
votes
1answer
567 views

Test Network Genesis Block

I am using BitcoinJ for my java application which fetches the test network's genesis block. I referred to the basics mentioned at JavaWorld and BitcoinJ's Google Code wiki. I am able to get it ...
4
votes
1answer
1k views

Building Signed Bitcoin Transaction in Java

I have been attempting to build my own raw transaction generator in Java which I can then broadcast on the testnet network. The problem is when I attempt to broadcast the transaction it says there is ...
2
votes
0answers
283 views

Broadcasting signed transaction from Watching wallet using bitcoinj

I am working with watching wallet and Offline wallet using bitcoinj, I created Watching Wallet using tpub key of Offline Wallet I am receiving payment on watching wallet Fine, now I want to ...
2
votes
1answer
637 views

How to sign a transaction using BitcoinJ

I am having problem signing the transaction using BitcoinJ library without the Wallet instance, I only have the Transaction class instance and the ECKey in order to sign the transaction. Is there a ...
1
vote
1answer
62 views

Fail to sign the Segwit Transaction's input in bitcoinj

I want to spend from a segwit address and it has a P2WPH script, I created this transaction just like creating a normal P2PKH transaction, but just changed the address of the input to the segwit ...
1
vote
0answers
34 views

How to sign a 2-of-2 multisig address?

I want to implement 2-of-2 multisig in bitcoinj, and I implement the methods which are used to sign the first time and the second time. But there is a bug that using the same key for the first signing ...
1
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0answers
87 views

How to sign an Altcoin transaction manually with 2 inputs and 2 outputs

So i'm working with the altcoin denarius which has the following raw TX structure. This is a transaction I am try to sign: Original: ...
1
vote
0answers
53 views

Bitcoinj Spend from a address directly without wallet

I am stuck trying to send coins from arbitary privateKey in bitcoinj. How can I make the following function work without using the Kit or Wallet classes? @Override public String transferCoin( ECKey ...
1
vote
0answers
299 views

List of crypto currencies built with java?

Is there a list of crypto currencies that was built with Java?
1
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0answers
376 views

Block chain receive payment api not working

I am building a little online app to accept bitcoin payments in my website. I have a blockchain.info wallet and I am following their Receive Payments Api, which can be visited here: http://blockchain....
1
vote
0answers
122 views

How return transaction hash from wallet to android app after payment?

Scenario: I have my android app where customers can pay by bitcoins. For this I created intent with uri like: bitcoin:[address]?amount=.. and using startActivityForResult it opens wallet with ...
1
vote
0answers
41 views

Is there a java library which could extract the first seen date and the last seen date of an address over a bitcoin network?

Apparently the bitcoinj does not provide such feature.
1
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0answers
147 views

API request of blockchain.info over Java stops spontaneously

In my java class, I extract the hash of transactions from the files of blk...dat, then obtain the data of the corresponding transactions via reading from the URL: https://blockchain.info/rawtx/+ hash. ...
1
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0answers
125 views

Payment Transaction Validation

I want to build a app which takes transaction id, source and destination address as input and need to validate the transaction (the specified amount is sent from address1 to address2. What is the ...
1
vote
0answers
47 views

Verification exception : Unexpected

i have cloned litecoin wallet and edit it connect to the network we have created. I disabled checkoints, changed params and the block syncs for 32 blocks. Then i get the following error 05-26 13:07:...
1
vote
0answers
228 views

Why I can't see the balance increasing in my wallet?

I wrote this function using bitcoinJ public Wallet getWallet(ECKey ecKey) { Wallet wallet = walletAppKit.wallet(); wallet.importKey(ecKey); wallet.addEventListener(new ...
1
vote
0answers
214 views

bitcoinj, unknown confidence level

I've got a bitcoin address A with its relative encrypted key K stored in a persistence storage. I am launching bitcoinj through the WalletAppKit class and calling awaitRunning to wait for the ...
1
vote
0answers
168 views

How to use Bitcoinj to authenticate signed messages?

I'd like to authenticate from java code on a website that makes use of javascript/ajax authentication like below: var key = new Bitcoin.ECKey(Crypto.util.hexToBytes(SHA256(password))); var ...
1
vote
0answers
110 views

BitcoinJ without PeerNetwork

I am writing a system which generates wallets on a per user basis. It must be capable to receive and send payments. So I have to keep the private keys encrypted on the system. Generating the ...
0
votes
0answers
28 views

Generate P2SH bitcoin address from WIF in BitcoinJ Java

I'm trying to create P2SH-Segwit bitcoin address from the WIF private key. I'm using the BitcoinJ library in Java. See the following code. String base58PrivateKeyString = "...
0
votes
0answers
12 views

Bitcoinj Doesn't increase wallet value

this is the initialization of wallet and block and PeerGroup : Wallet wallet = new Wallet(params, KeyChainGroup.createBasic(params)); BlockChain chain = new BlockChain(params, wallet, new ...
0
votes
1answer
33 views

How to transform a private key into an ECKey?

I´d like to construct an ECKey from a hardcoded private key but it´s not working... First try If I run the code in this example the key import is working just fine. But since I actually want so send ...
0
votes
1answer
27 views

Add bitcoin payments to java app using BitcoinJ

I need to add Bitcoin payment to my application using the BitcoinJ library, but I'm new to using Bitcoin. I have one thought To create a new address for each new user, but I don't know if this is the ...
0
votes
0answers
27 views

Sign Multisignature Transaction with only 1 of the needed keys using BitcoinJ?

If I have an unsigned Raw Transaction whose inputs are from a multisignature wallet, can I sign the transaction with only of the N needed keys and having the output as raw transaction again using ...
0
votes
2answers
206 views

Verify Bitcoin Transaction

Following the great post [Redeeming a raw transaction step by step example required, I came up with code below but the verification failed. // pubkeyBytes, len: 65 // ...
0
votes
1answer
579 views

How can I generate public address from an xpub key in Java?

I have an xpub key with which I want to generate all addresses which have been used or will be used and then find out the keys which have balance. Here's a sample xpubkey with balance- ...
0
votes
1answer
266 views

GDAX Java Limit Order (HTTP Post)

Trying to send HTTP Post request to GDAX with auth. The 'GET' requests work fine and I'm unsure if I am passing the json params correctly as I keep getting Bad Request. private static JsonObject ...
0
votes
0answers
144 views

blockChainDownloadLocked ignoring the duplicate request error

I work with a bitcoin wallet app using the Java/BitcoinJ. The app has custom features such as showing balance, transactions, address and sending option. It was running fine and suddenly, I get the ...
0
votes
0answers
200 views

Library ZMQ to Java does not work

I am trying to connect to a bitcoin node using the ZMQ library for Java. the problem is that when I try to receive a response the code remains frozen. Returns nothing. This is my code: public class ...
0
votes
0answers
2k views

blockchain.info websocket: Error code = 1006, Unexpected end of stream

I am using javax.websockets to have a webSocket connection with Blockchain.info, except that it closes down after random intervals, and I can see the close reason as: 'Unexpected end of stream', ...
0
votes
0answers
214 views

Verifying mrkl_root from two children nodes in JAVA

Let's use the following block for a reference: http://blockexplorer.com/rawblock/00000000000000001e8d6829a8a21adc5d38d0a473b144b6765798e61f98bd1d According to my understanding (correct if wrong), I ...