java玩轉區塊鏈-基礎篇-solidity語法-基礎型別-有解無憂

java玩轉區塊鏈-基礎篇-solidity語法-基礎型別

- java環境配置
- 代碼準備
- - - maven
    - - 完整solidity
    - 執行步驟
- 基礎型別
- - 布爾型別
  - - - 型別標識:
      - 字面常量值:
      - 運算子:
      - 短路規則:
      - example
  - 整形
  - - - 型別標識:
      - 字面常量值：
      - 除法截斷
      - 代碼
  - 浮點型別
  - 地址型別
  - - - 型別標識:
      - 字面常量值：

可以不讓搞，但是不允許你不會

java環境配置

jdk版本，jdk1.8+；
IDE環境，ideas；
依賴包，web3；
區塊鏈網路，開發網，Ganache；

代碼準備

以下是本章所有實體的代碼

maven

<properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.web3j</groupId>
            <artifactId>core</artifactId>
            <version>5.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.web3j</groupId>
            <artifactId>contracts</artifactId>
            <version>5.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.web3j/web3j-unit -->
        <dependency>
            <groupId>org.web3j</groupId>
            <artifactId>web3j-unit</artifactId>
            <version>4.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>23.0</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.web3j</groupId>
                <artifactId>web3j-maven-plugin</artifactId>
                <version>4.6.5</version>
                <configuration>
                    <soliditySourceFiles/>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>central</id>
            <name>central</name>
            <url>https://maven.aliyun.com/repository/central</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>jcenter</id>
            <name>jcenter</name>
            <url>http://jcenter.bintray.com/</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>maven-net-cn</id>
            <name>Maven China Mirror</name>
            <url>https://dl.bintray.com/ethereum/maven</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

完整solidity

pragma solidity ^0.5.0;

contract TypeDescContract {

    constructor() public {

    }

    function boolTrunc() public view returns (uint){
        uint a = 12;
        a < 13 || a++ < 14;
        return a;
    }

    function boolTrunc2() public view returns (uint){
        uint a = 12;
        a < 13 && a++ < 14;
        return a;
    }

    function uintDivTrunc() public view returns (uint) {
        uint a = 5/2.5;
        return a;
    }

    function getSelfAddress() public view returns (address){
        return msg.sender;
    }
}

執行步驟

(1) 啟動ganache
(2) 在專案目錄resources中撰寫合約腳本
在這里插入圖片描述

(3) 執行腳本轉化java類
在這里插入圖片描述
雙擊執行插件命令，生成java類，
(4) 部署合約到ganache本地開發鏈

package com.lession.type;

import org.web3j.crypto.Credentials;
import org.web3j.model.ArrayContract;
import org.web3j.model.TypeDescContract;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.http.HttpService;
import org.web3j.tx.gas.StaticGasProvider;

import java.math.BigInteger;

public class TypeDescMain {
    public static void main(String[] args) throws Exception {
        Web3j web3j = Web3j.build(new HttpService("HTTP://127.0.0.1:7545"));
        String pk = "d8673b8d4c7a9345c7cd8bb91574389d29b1e69cdbe0be9ac8fdf10f43e69c55";//(1)
        Credentials credentials = Credentials.create(pk);//(2)
        System.out.println("Account address: " + credentials.getAddress());
        System.out.println("Account ak: " + credentials.getEcKeyPair().getPrivateKey().toString(16));
        System.out.println("Account pk: " + credentials.getEcKeyPair().getPublicKey().toString(16));
        StaticGasProvider provider = new StaticGasProvider(new BigInteger("20000000000"),new BigInteger("6721975"));
        TypeDescContract contract = TypeDescContract.deploy(web3j,credentials,provider).send();//(3)
        System.out.println("contractAddress:" + contract.getContractAddress());//(4)
    }
}

代碼解釋:
(1) 從ganache中找一個賬戶的私鑰
(2) 通過私鑰生成鑒權資訊
(3) 部署合約
(4) 列印生成鏈上合約地址

(5) rpc呼叫合約

package com.lession.type;

import org.web3j.crypto.Credentials;
import org.web3j.model.TypeDescContract;
import org.web3j.protocol.Web3j;
import org.web3j.protocol.http.HttpService;
import org.web3j.tx.gas.StaticGasProvider;

import java.math.BigInteger;

public class TypeDescClient {
    public static void main(String[] args) throws Exception {
        Web3j web3j = Web3j.build(new HttpService("HTTP://127.0.0.1:7545"));
        String pk = "d8673b8d4c7a9345c7cd8bb91574389d29b1e69cdbe0be9ac8fdf10f43e69c55";
        Credentials credentials = Credentials.create(pk);
        System.out.println("Account address: " + credentials.getAddress());//(1)
        System.out.println("Account ak: " + credentials.getEcKeyPair().getPrivateKey().toString(16));
        System.out.println("Account pk: " + credentials.getEcKeyPair().getPublicKey().toString(16));
        StaticGasProvider provider = new StaticGasProvider(new BigInteger("20000000000"),new BigInteger("6721975"));
        TypeDescContract contract = TypeDescContract.load("0x64de7ed9f8a2fe5c6303cc980c7d15ccac873f85",web3j,credentials,provider);//(2)
        System.out.println("boolTrunc:" + contract.boolTrunc().send().toString()); //(3)
        System.out.println("boolTrunc2:" + contract.boolTrunc2().send().toString());
        System.out.println("uintDivTrunc:" + contract.uintDivTrunc().send().toString());
    }
}

代碼解釋:
(1) 通過私鑰生成鑒權
(2) 通過合約地址，加載合約
(3) rpc呼叫合約函式

基礎型別

布爾型別

型別標識:

bool

字面常量值:

true 或 false

運算子:

!(邏輯非) ,&&(邏輯與),||(邏輯或),==(等于),!=(不等于),<=(小于等于),<(小于),>=(大于等于),>(大于)

短路規則:

||和&&遵循短路規則，f(x)||g(y)如果f(x)為true，則g(y)不會執行，f(x)&&g(y),如果f(x)為false，則g(y)不會執行，

example

合約代碼

function boolTrunc() public view returns (uint){
        uint a = 12;
        a < 13 || a++ < 14;
        return a;
    }

    function boolTrunc2() public view returns (uint){
        uint a = 12;
        a < 13 && a++ < 14;
        return a;
    }

java代碼

System.out.println("boolTrunc:" + contract.boolTrunc().send().toString()); 
        System.out.println("boolTrunc2:" + contract.boolTrunc2().send().toString());

執行結果:

boolTrunc:12
boolTrunc2:13

boolTrunc中的a++并未執行，boolTrunc2中的a++執行了變成了13

整形

型別標識:

uint,uint8~uint256

字面常量值：

12 --> 為uint256

除法截斷

5/3=1

代碼

solidity

function uintDivTrunc() public view returns (uint) {
        uint a = 5/2.5;
        return a;
    }

java

System.out.println("uintDivTrunc:" + contract.uintDivTrunc().send().toString());

執行結果

uintDivTrunc:2

浮點型別

不支持

地址型別

型別標識:

address

字面常量值：

0x45b6d967bd2962ebb232c2a8065ce9e4abc93aab
地址型別存盤一個 20 位元組的值

java玩轉區塊鏈-基礎篇-賬戶

轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/305523.html

標籤：區塊鏈

上一篇：四、Linux磁盤與檔案系統管理

下一篇：《區塊鏈技術與應用》學習筆記13——ETH權益證明