How Java connects to blockchain

2. How can blockchain be connected in sequence
blockchain is composed of a series of blocks generated by cryptographic algorithm. Each block is filled with transaction records, and the blocks are connected in sequence to form a chain structure, which is the blockchain ledger
taking bitcoin as an example, when miners generate new blocks, they need to calculate the new hash value and random number according to the hash value, new transaction block and random number of the previous block. In other words, each block is generated on the basis of the previous block data, which ensures the uniqueness of the blockchain data
because subtle changes in transaction records will completely change the result of hash value, miners can't cheat when competing for computing power. Each miner must wait until the previous block is generated before starting to calculate the qualified random number according to the data of the previous block, which ensures the fairness of mining.

3. 1.
the underlying development of blockchain can't be realized with Java
2.
to do the upper development, you only need to dock according to the given open source interface, and then use the language you are good at to develop what you need
3.
now there are many blockchain system templates, you can go to see what development cases there are

5.

The solution to watch water, mirror fog:

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with a few layers of toilet paper or easy to absorb moisture flannelette will watch tightly, put under the bulb baking for about 30 minutes, you can eliminate the water mist inside, but avoid it close to the bulb or directly baking, so as not to cause surface heat deformation

with the surface facing inward and the bottom shell facing outward, put it on the wrist. After a few hours, the water mist in the watch can also be eliminated

if there is silica gel, put the silica gel and the watch with water into a closed container. After a few hours, take out the watch, and the water mist in the watch will disappear

if the watch is seriously affected by water, it is better to send it to the watch shop to wipe oil to eliminate the water in the watch, so as to avoid rust of parts in the watch

note: in order to prolong the service life of the watch, try to avoid fog and water droplets in the waterproof watch. Do not wear the watch when washing face, bathing, swimming and other "hydrophilic" activities. Do not be affected by water vapor and hot vapor. In rainy days, do not be affected by rain

6. I don't know about it. Of course, the virtual currency is traded in the virtual place. You can buy some virtual things to make up for yourself.

7. Recommend EBIT, you can go to the official website.

8. 2019 is a year of rapid development of bitcoin derivatives, especially in the second half of the year, major exchanges rush to launch futures contract trading, it seems that spot trading + futures trading has become the standard configuration of exchanges. When the market procts are highly concentrated, the market competition is very fierce. The contract market is in full swing, and the vast majority of market shares are held by bitmex, okex, fire currency and other exchanges. As a result, the contract market share is getting smaller and smaller. If you want to win a place in the derivatives market, you have to work hard in proct research and development, which is bound to break through the current market pattern

although the futures contracts were launched last year, for the bitcoin derivatives market, futures alone is obviously not perfect, and there is a huge space for the bitcoin derivatives market. However, bitoffer exchange aims at the bitcoin derivatives market, relying on the advantages of the top financial R & D team, It is the first to launch bitcoin options and bitcoin ETF funds in the world, which is favored by the majority of users<

Lucian, chief analyst of bitoffer exchange, said that BTC options and ETF funds were launched to make up for the current vacancy in the bitcoin derivatives market. What other exchanges can't do is for us to do. The launch of bitcoin options and ETF is not only the improvement of the bitcoin derivatives market, but also a performance of promoting the development of the market. Any investment market can not do without derivatives, because investment is certainly risky, and derivatives can be used as risk hedging tools<

Lucian also revealed that bitoffer is currently developing and building a new bitcoin futures contract trading in the instry, which is expected to be launched in the first quarter of 2020. It is worth noting that the platform has been launched for spot, options and ETF fund trading. If the futures contract trading is launched in the first quarter, it means that, Bitoffer will become the world's first exchange with a full range of bitcoin spot and derivatives routes. By then, bitoffer is bound to win a place in the derivatives market!

9. Blockchain is a rapidly developing field. You have to have a Java foundation and be familiar with JavaScript. You can start with JavaScript and other frameworks, and hope to continue to develop and learn in this direction. With the popularity of ICO and mining trends, you don't hesitate to try blockchain development. Blockchain technology has attracted the attention of banks in various countries and regions. All in all, blockchain has a bright future
blockchain can solve many problems:
1. Ensure the security of bank deposits
e to fraud, banks will lose a huge amount of money every year. Blockchain has almost impeccable security, which can help them solve this problem. The bank customer who switches to blockchain wallet is replaced by a unique identification number. In addition, they use the private key to access the money. With the help of blockchain, only the account owner can process the funds - even the bank can't get them. These security measures ensure the security of bitcoin and other cryptocurrencies, so that banks can easily protect deposits
2. Cloud storage on blockchain can better resist hacker attacks
cloud storage companies use central servers to store data. For this reason, the risk of hackers stealing information increases - by accessing the server, hackers will automatically penetrate the entire network. Cloud storage on an apartment can protect data in a decentralized way, and the nodes are disconnected. Therefore, they are not vulnerable to attack, even hackers attack a node will not damage the entire network
3. Faster cargo transportation
in terms of logistics, it is necessary to organize cargo transportation correctly and quickly. The key is to be able to track goods throughout the supply chain. With the help of blockchain technology, this process will become more secure and transparent. In addition, decentralization of continuous records in the register would rece the role of people and the possibility of delays
4. Election cheating
election cheating, forged signatures, holding meetings without informing all members are the most common problems in corporate governance. All these problems can be solved by the integration of blockchain technology. For example, it can track and count votes, eliminating the possibility of forging someone's signature or voice. Instead, each voting participant will receive a unique key as identification.