Java Ethereum development video

1. Ethereum, ETH for short. At the end of 2013, vitalik released the white paper of Ethereum, and in July 2014, the pre-sale of Ethereum began. At that time, insiders called this kind of token issue "crowdfunding". Through the 42 day pre-sale, the Ethereum team raised more than 30000 bitcoins through the pre-sale of 60102216 Ethernet coins; In addition, the early contributors who participated in the development before the pre-sale and the developers who have been engaged in project research for a long time are allocated according to 9.9% of the total amount of Ethernet coins sold at that time. So when Ethereum was officially released, there were more than 72 million Ethereum coins. After the end of Ethereum's pre-sale, it uses the proof of work mechanism POW for mining, and rewards the miners according to 26% of the total amount issued at that time every year. In October 2014, Ethereum reced the block output time from 60 seconds to 12 seconds, and now it is basically stable at 15 seconds, with 5 etheric coins awarded for each block
although the pow mining mechanism is adopted, the block out mechanism of Ethereum is different from that of bitcoin. Due to the short block time of Ethereum, Ethereum is easy to form isolated blocks. Isolated blocks refer to the blocks that are not on the longest chain. Bitcoin's isolated blocks have no block rewards, but in Ethereum, isolated blocks can be referenced. The referenced isolated blocks are called "Uncle blocks", and their packaged data will also be recorded in the blockchain. Unlike bitcoin, Ethereum's TERT block has a reward, and each TERT block can get a reward of 4.375 Ethernet coins at most
Ethereum is a programmable and Turing complete blockchain development platform, which is equivalent to a decentralized global computer. In a programming system, there are usually some virtual machines to compile and execute. Java has JVM. In Ethereum, there is also Ethereum's virtual machine EVM, which can execute any complex algorithm code. Developers can use existing programming languages such as JavaScript or Python to create their own applications on Ethereum. Through Ethereum's virtual machine, you can easily issue digital assets, write smart contracts, set up and run decentralized applications, and set up decentralized autonomous organizations
eth is also known as the internal fuel of Ethereum. Unlike currency digital assets, Ethereum is not only used for transfer, but also for payment of smart contracts
in order to prevent the Ethereum blockchain from being full of junk contracts and junk applications, and to establish and run smart contracts on Ethereum, you must use eth to pay for smart contracts. For example, when you transfer your newly created digital assets on the Ethereum blockchain, you need to use eth to pay the handling fee instead of your newly created digital assets.

2. If this is only the most basic, it can be done by 100000 yuan. If you need to add other functions, it depends on the difficulty of the functions you add. If you want affordable price and good service, I suggest you consult Shengshi Huacai company. I've used it for two years, and almost no problems have occurred.

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Blockchain projects require high efficiency, so most of the core source code development is using C / C + +. However, if you are doing a blockchain project, unless you need to make a lot of adjustments to the source code, you may not choose to use Java. For general DAPP applications, java development should also be a good choice. For example, in the case of Ethereum blockchain, there is a web3j class library for Java, which is very convenient; Bitcoin has bitcoin J class library, which is also easy to use. It still depends on the level of application, what to do, and the situation of the team

share two Java blockchain tutorials:

1. java bitcoin details

2. java Ethereum development

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4. Shengshi Huacai company has done a good job in the development of Ethereum.

5. My computer - & gt; Attribute - & gt; Advanced - & gt; Environment variables - & gt; Add the following environment variables to the system variables:
java_ The home value is: the directory where JDK is installed, and mine is C: &# 92; Program Files\ Java\ jdk1.6.0_ 34
the classpath value is:;% JAVA_ HOME%\ lib\ tools.jar;% JAVA_ HOME%\ lib\ dt.jar;% JAVA_ HOME%\ bin;( Pay attention to the & quot& quot; To add)
Path: append at the beginning.;% JAVA_ HOME%\ bin;% JAVA_ HOME%\ jre\ bin;( Pay attention to the & quot& quot; To add)

after the installation, you can check whether the JDK is installed successfully. Open the CMD window and enter Java – version to view the version information of JDK.

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Ethereum specifies the JSON RPC API application development interface that each node needs to implement. This interface is transport independent. Applications can use this interface protocol to operate Ethereum nodes through HTTP, websocket or IPC and other communication mechanisms:

7. Xu Mingxing, He Yi and Zhao CHANGPENG<

Xu Mingxing: founder of okcoin, technical otaku, and now CEO of the company

He Yi: former host of a tourism channel, later joined okcoin, mainly responsible for participating in some instry activities and promotion activities, and now is the vice CEO of the company<

Zhao CHANGPENG: he used to be the head of blockchain China, a world-famous online wallet. Later, he moved to okcoin, mainly responsible for the development of platform technology and projects

this is the legendary bitcoin tiantuan of okcoin

in the bitcoin mining instry, Zhang Nangeng is the founder of Avalon. It is his mining machine that has completely subverted the bitcoin mining instry and is currently deploying large-scale mines.

8. Link aggregation. Different types of switches support different numbers. You can enter
interface eth trunk? On the switch? It will prompt you with a numerical range
this numerical range is the number of supports. But are you sure you have so many ports to use
for example, you can use two ports for one aggregation. 24 port switching supports 12 aggregations at most< Moreover, link aggregation is the connection between switches. Generally, one uplink and one downlink are enough. Unless you're a core exchange or something special.