Ethereum coin data interface
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They are:
bitcoin
the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's ideas, the open source software was designed and released, and the P2P network was built on it. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
bitcoin cash
bitcoin cash is a new version of bitcoin with different configurations launched by a small number of bitcoin developers
extended data:
virtual currency refers to non real currency. Well known virtual currency, such as network company's network currency, Tencent company's Q currency, Q point, Shanda company's voucher, Sina's Micro currency (used for micro games, Sina reading, etc.), chivalrous Yuanbao (used for chivalrous road game), silver pattern (used for bixue Qingtian game)
the popular digital currencies in 2013 are bitcoin, Leyte coin, infinite coin, quark coin, zeta coin, BBQ coin, pennies (Internet), invisible gold bar, red coin and prime currency. At present, hundreds of digital currencies are issued all over the world. Popular in the circle & quot; The legend of "bitcoin, Wright silver, infinite copper, pennies aluminum"
each version of Ethernet has a maximum cable length limit (that is, the length without amplification). Signals within this range can propagate normally, and signals beyond this range cannot propagate
in order to allow the construction of a larger network, repeaters can be used to connect multiple cables. Repeater is a physical layer device, which can receive, amplify and retransmit signals in two directions
extended data
several common Ethernet interface types
1. SC optical fiber interface
SC optical fiber interface has been applied in the era of 100base TX Ethernet, so it was called 100base FX at that time (F is the abbreviation of optical fiber). However, at that time, because the performance was not more prominent than twisted pair, but the cost was higher, so it was not popularized. Now the instry vigorously promotes gigabit network, and SC optical fiber interface is re valued
2. RJ-45 interface
this kind of interface is the most common network equipment interface, commonly known as "crystal head", and the professional term is RJ-45 connector, which belongs to the type of twisted pair Ethernet interface. RJ-45 plug can only be inserted along the fixed direction, and a plastic spring piece is set to be stuck with RJ-45 slot to prevent it from falling off
3. FDDI interface
FDDI has the highest transmission rate among the mature LAN technologies. It has the characteristics of timed token protocol, supports a variety of topologies, and its transmission medium is optical fiber. Fiber distributed data interface (FDDI) is a set of protocols developed by American National Organization for Standardization (ANSI) to transmit digital signals on optical cables
reference source: Network Ethernet interface
If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records
the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:
< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});
Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query
recommend a practical introction, you can see: Ethereum tutorial
Both aoex and E-app can view real-time dynamic transaction
data
choose your own direction
the cost of developing an interface is not so high. Except for EOS, there is not much data to be chained, which is basically completed locally. As a top blockchain technology developer in China, weisanyun is still a good technology developer.
After reading the answers of other respondents, I really want to laugh. It's not terrible to pretend that I don't understand. What's terrible is to answer blindly. There's something wrong with this question. The burst of 5.7 billion yuan has nothing to do with a drop of 10 cents. It can even be said that its disappearance is e to the sharp rise. So where is the decline? If bitcoin really falls, it will not be 5.7 billion capital washed away, it will be tens of billions, hundreds of billions of capital evaporated, those who talk about trends and development, please study the capital and stock market well, and by the way, please search for the meaning of the word "burst", no culture is too terrible
in addition, I would like to make a digression. Recently, a hot topic is fund. In 2021, the annual meeting is more or less a national fund. In 2020, the fund manager is still a good active fund. Even if the position is not changed, the annual yield will reach at least 40%, but this does not mean that this year is still OK, It's not that everyone can make money playing with funds. it's similar to the nature of stocks. Index funds, stock funds and even active funds are risky. I think many people say that they should get on the bus quickly. They are really worried about your funds of course, 2021 may be a bull market. It is estimated that the whole network has spread, many people are rubbing their hands to make a lot of money, but I can't do much. I just advise you not to go with the flow too much, don't be greedy, and don't think you are. That's all. Good luck
Why develop digital currency? From the perspective of the central bank, there are six advantages:
first, to improve the convenience and transparency of economic transactions; second, to rece the high cost of the issuance and circulation of traditional paper money; third, to better support economic and social development; fourth, to help the comprehensive realization of Inclusive Finance; fifth, to rece money laundering, to promote the development of the economy and society Sixth, improve the central bank's control over money supply and circulation
steps of digital currency development:
the first step,
first, we need to download the source code of a blockchain system from git, such as choosing the backbone code of bitcoin to download the relevant source code
At the same time, prepare the corresponding compiling environment (c + + is recommended in Linux) and install the corresponding development environment and toolsthe second step and
code all need to be compiled, so you need to prepare the compilation environment and tools, download the environment compilation tools, configure
system environment variables, QT environment and other files, and compile commands are described in detail in the files in ITC source code
however, the construction of the system and development environment, program compilation and other processes are cumbersome, so it is not recommended for ordinary users to make their own. For developers, it may take 2-3 days to install and configure for the first time
the third step,
take bitcoin development as an example, it is the development environment of Q. after downloading the source code and configuring the environment, open the source code of the bitcoin core in qtcreator, configure relevant files and compilers, and start to try to compile the client of the bitcoin core
Step 4,
transform into your own digital currency, open each source file, find the corresponding local adjustment parameters, such as adjusting
the number of coins in each block, the total output, the adjustment difficulty, and so on. Then the most critical point is to change the name to your own currency
name as you want, and don't forget to replace the related icons in the resource folder. If all goes well, after re compiling, your new coin will be invented successfully
for the development of this digital currency, the technology is relatively professional, so it is better to have a professional team to assist
framework for digital currency development:
1. Build Ethereum private chain test environment and public chain node environment configuration
2. Ethereum transaction and confirmation principle
3. Ethereum JSON RPC interface
4. Ethereum transfer and withdrawal principle
5. The server connects Ethereum public chain interface, and its own server stores business data, Public chain storage transaction anonymous data
6, private key security processing
the following is the development code example:
for example, the common digital currency wallets in the market are:
app class: kcash Imtokenweb: myethereumwallet Google browser plug-in: metamask
one of the most commonly used is imtoken
blockchain transaction technology concept:
let's take a look at how blockchain transaction is handled with bitcoin as an example. In order to send a certain amount of bitcoin to another wallet, you need the following information: the address to send the funds to your wallet, the amount of cryptocurrency you want to send
the ID of the recipient's wallet
each transaction is signed with a unique confidential private key. Once the payment is signed by the sender, it becomes publicly available. The transaction still needs to be confirmed so that the payee can get the money. In order to confirm the transaction, it is necessary to generate a new chain block
these blocks are generated by complex mathematical calculation to find the unique key. It takes 10 minutes to create a new block, and the person who finds the key gets a certain amount of coins as a reward. Once a new block of the chain is created, it is not possible to remove it from the database or change the information in some way. Therefore, blockchain transaction is final and irreversible
three core advantages of digital currency:
first, digital currency is a fair currency
digital currency has no specific issuing institution, is not issued by a country, only depends on a specific algorithm, which means that digital currency can not be manipulated by manipulating the number of issues, so digital currency is a free, non-state currency
we can see that there are many countries that directly recognize the virtual currency, so if there is a demand, it needs a trading platform
many investors who want to build a virtual currency trading platform now, why can't they go to these areas to build a trading platform? Building a virtual currency trading platform is a good business opportunity, isn't it
Second, the security factor of digital currency is higher.
although the emergence of paper money facilitates the transactions in our daily life, there are risks of being stolen and received. Although e-money can avoid these risks, there will be new problems such as theft and swiping
digital currency can avoid the above problems. And broadcast every transaction record on the network. Yes, all nodes save all the currency circulation information, so that any node can easily find the currency circulation before the transaction
Thirdly, the transaction of digital currency can realize anonymous transaction. Although you can query the flow information of each account according to the local complete transaction recordsbut we can't know who the owner of this account is, and no one has the ability to manipulate the digital currency on other people's accounts, which protects the privacy of users
if you also hold trading digital currency, foreign exchange gold, crude oil, contract Futures: