Radar wallet blockchain general ledger query

1. In order to understand the blockchain wallet, we must first understand several core concepts
1. Wallet address: similar to the bank card number, a person can have multiple bank cards. Similarly, he can also have multiple wallet addresses. A wallet address can only correspond to one private key
2. Wallet ID: customer ID (name) similar to bank card
3. Public key and private key: the holder of the private key is the holder of the currency in the bank card. The private key can calculate the public key, the public key can generate the wallet address through a series of digital signatures, and the data encrypted by the private key can be decrypted by the public key, or vice versa
I know this area quite well, and I have some ideas to develop a blockchain wallet. After all, it is a high-tech wallet. Before I learned about a development company called Xuanling technology on the Internet, and also consulted the people over there. I felt that it was quite professional. I hope I can help you~

2. The transaction direction of bitcoin can be queried. Bitcoin transactions will be recorded on the bitcoin blockchain to find out the liquidity of bitcoin and from which wallet to which wallet. However, you only know which wallet is transferred to, and you don't know who the wallet belongs to. Bitcoin is both transparent and anonymous. Transactions and flows are public and will be recorded, but the person who trades is anonymous. Some scholars found that through the flow of bitcoin, transaction users can be found. They need to use certain technical means, and it is particularly troublesome. At present, it is only in the theoretical stage.

3.

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first and last bus: 05:30-22:45

starting ticket price: 3 yuan

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3 Zhangjiang Gaoke

Longyang Road line 16 line 7

5th century park

6 Shanghai Science and technology park

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4. In the actual development, we often encounter some situations like this,
(1) in the case of sudden high concurrency, when the server is under great pressure and calls some methods for more than 100ms and does not respond, we should automatically reject the service instead of blocking until the server crashes, It can be regarded as a disguised service degradation
(2) for the unpredictable code that may have deadlock, add time threshold limit to avoid unlimited resource competition
(3) for the unpredictable code that may have deadlock, add time threshold monitoring, Avoid dead cycle deterioration

some mature open source frameworks generally have the function of timeout response, such as
search framework: Lucene, Solr, elasticsearch,
RPC framework: Dubbo, thrift,
service coordination framework: zookeeper, etc.
if we want to add this function, what should we do
in fact, it's not difficult to add a timing function before and after the method call. If the threshold is exceeded, the thread should be terminated actively and the exception code should be thrown. Of course, in order not to affect the operation of the main service, this code should run independently in a sub thread, rather than coupled in the main thread. The idea is roughly the same. Of course, in order not to build a wheel repeatedly, we suggest to use Google's open source guava toolkit, which provides many useful functions, including the automatic termination of timeout method introced this time, and some functions to limit network traffic or the number of visits within a specified period of time, You can see guava's documentation for yourself<
timelimiter is an interface. There are two subclasses below,
faketimelimiter, which is often used to limit time-out debugging ring debugging.
simpletimelimiter is often used in formal methods, which call method time-out, that is, throw exception.
this paper focuses on the use of simpletimelimiter, There are mainly two methods in this class:
(1) newproxy implements timeout interception through JDK dynamic proxy and callwithtimeout
(2) callwithtimeout implements timeout interception through callable callback
the difference between the two methods lies in that the strategy implemented through proxy can be applied to every called method in this class, The implementation of timeout interception
and the implementation strategy through callback is applicable to the implementation of timeout interception only for a certain code block or method
introce the latest guava package through Maven:
java code

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A: Interception Based on proxy mode:
since guava uses JDK dynamic proxy to implement AOP interception, it requires that the proxy class must have an interface implementation, so it's a little troublesome to use.
we need to define an interface first, then define the implementation class, and rewrite the method to be called:
b: callback based usage, which is relatively simple, Because there is no need to use proxy mode,
both methods can implement method call timeout interruption, proxy mode is suitable for class level method timeout interruption, while callback based mode is more suitable for any single method.

5. Blockchain wallet development? Henan keoo has a case for your reference, you can learn about it.

6.

1. Radar is a popular blockchain application platform in China, and radar wallet is a popular blockchain international wallet< The br />

2. radar wallet is like the global Alipay. As long as the deposit is in the purse system, it will be presented to the radar money every day, and it will be compound profit and profit on the day. The annual revenue will be as high as 300%.

3. To put it more simply, it is similar to MasterCard, except that the traditional bank card is legal currency for deposit, withdrawal and transfer, such as RMB, US dollar, pound sterling, etc., while the radar wallet can not only deposit, withdraw and transfer legal currency, but also deposit, withdraw and transfer digital currency

4. In addition, digital currency in radar wallet is equivalent to financial management. Of course, you can also transfer money online or exchange (various currencies) to earn the price difference. The premise is: must be able to operate! Simultaneous interpreting, like traditional bank cards or Alipay, will not save money and make money transfer. p>

< H2 > extended materials:

radar currency is an internet financial tool, which helps users to pay, transfer and freely convert global currency simply, quickly and at low cost

is a kind of virtual currency, which, like reborn and bitcoin, is secure through three technologies: open source, decentralization and no central server

has the property of currency, and is also a financial trading platform, which can break financial barriers and prevent inflation; Stronger connectivity, opening up the global financial Island, recing the resistance of the financial system, enhancing efficiency, and building a global unified Internet financial system

7. Into the computer version of the radar wallet, home scan 2D code, choose your mobile phone system installation, there will be no fake radar wallet.

8. In order to get the maximum income, reasonable household division can achieve 3.5% monthly interest, a wallet interest, why not?

9. If the QR code of radar Coin Wallet is lost,
then you can apply for another one on the platform
after the application, the platform will mail you the QR code
hope it can help you