本文分別說明.NET CORE與Spring Boot 編寫控制台程式應有的“正確”方法,以便.NET程式員、JAVA程式員可以相互學習與加深瞭解,註意本文只介紹用法,不會刻意強調哪種語言或哪種框架寫的控制台程式要好。 本文所說的編寫控制台程式應有的“正確”方法,我把正確二字加上引號,因為沒有絕對的 ...
本文分別說明.NET CORE與Spring Boot 編寫控制台程式應有的“正確”方法,以便.NET程式員、JAVA程式員可以相互學習與加深瞭解,註意本文只介紹用法,不會刻意強調哪種語言或哪種框架寫的控制台程式要好。
本文所說的編寫控制台程式應有的“正確”方法,我把正確二字加上引號,因為沒有絕對的正確,因人而異,因系統設計需求而異,我這裡所謂的正確方法是指使用面向對象,依賴註入IOC,切麵控制AOP等編碼規範來提升程式的性能、整潔度、可讀性、可維護性等,最終達到讓人感覺有點高大上,有點優雅的樣子。
先來說說.NET CORE編寫控制台程式,目前網路上大把的講解ASP.NET CORE的編寫規範,反而對於.NET CORE控制台程式編寫規範介紹比較少,大多停留在Hello Word 程式中,而本文則來講講.NET CORE控制台的編寫規範(應有的優雅姿勢)^ v ^
如果說不講什麼IOC,DI,AOP等,不講擴展性,規範性,全部面向過程(方法)編程,那估計沒什麼好講的,因為無非就是定義一個class,然後在class中定義一堆的method(方法),如果在方法中需要使用到其它第三方組件,則直接單獨引用,引用後進行簡單封裝util工具類的靜態方法,甚至也不用封裝,直接使用原生的方法,總之全部都是方法調方法。而這裡所演示的編寫控制台方法均是儘可能的使用.NET CORE所具有的特性,只有這樣才能體現出.NET CORE框架的優勢,否則普通控制台程式與.NET CORE控制台程式有什麼區別。
編寫.NET CORE控制台程式優雅姿勢一:(直接使用.NET CORE的 IOC、Logging、Config組件)
代碼如下:
//Program.cs using Microsoft.Extensions.DependencyInjection; using System; using Microsoft.Extensions.Logging; using Microsoft.Extensions.Configuration.Json; using Microsoft.Extensions.Configuration; using System.IO; namespace NetCoreConsoleApp { class Program { static void Main(string[] args) { //設置config文件 var config = new ConfigurationBuilder() .SetBasePath(Directory.GetCurrentDirectory()) .AddJsonFile("appSettings.json", optional: true, reloadOnChange: true).Build(); //設置依賴註入 var provider = new ServiceCollection() .AddLogging(configLogging => //設置日誌組件 { configLogging.SetMinimumLevel(LogLevel.Information); configLogging.AddConsole(); }) .AddScoped<IConfiguration>(p => config) .AddScoped<HostService>() .BuildServiceProvider(); var hostService = provider.GetService<HostService>(); hostService.RunAsync();//統一入口服務 Console.WriteLine("提示:程式已正常啟動運行,按任意鍵停止運行並關閉程式..."); Console.ReadLine(); } } } //HostService.cs
using Microsoft.Extensions.Configuration; using Microsoft.Extensions.Logging; using System; using System.Diagnostics; using System.Threading; using System.Threading.Tasks; namespace NetCoreConsoleApp { public class HostService { private readonly IConfiguration config; private readonly ILogger<HostService> logger; public HostService(IConfiguration config, ILogger<HostService> logger) { this.config = config; this.logger = logger; } public void RunAsync() { Task.Run((Action)Execute); } /// <summary> /// 控制台核心執行入口方法 /// </summary> private void Execute() { //TODO 業務邏輯代碼,如下模擬 Stopwatch stopwatch = Stopwatch.StartNew(); for (int i = 1; i <= 100; i++) { Console.WriteLine("test WriteLine:" + i); Thread.Sleep(100); } stopwatch.Stop(); logger.LogInformation("Logging - Execute Elapsed Times:{}ms", stopwatch.ElapsedMilliseconds); } } }
因為要使用.NET CORE相關核心組件,故需要引用相關的NuGet包(引用包的方式有多種方式),而且預設的.NET CORE控制台只會生成DLL並不會生成EXE啟動程式,故如果僅在WIN系統下使用,還需要設置生成方式等,詳細配置屬性如下:(項目文件csproj)
<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <OutputType>Exe</OutputType> <TargetFramework>netcoreapp2.2</TargetFramework> <RuntimeIdentifiers>win10-x64</RuntimeIdentifiers> <SelfContained>false</SelfContained> </PropertyGroup> <ItemGroup> <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.2.0" /> <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="2.2.0" /> <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="2.2.0" /> </ItemGroup> </Project>View Code
如上代碼雖簡單但代碼編寫順序很關鍵,這裡進行說明一下:
1.因為一般應用程式都會有config文件,故我們需要先通過new ConfigurationBuilder來設置config文件的方式及路徑;
2.因為要使用.NET CORE預設的IOC框架,故new ServiceCollection,然後將相關的依賴服務組件註冊到IOC容器中;
3.config、logging 均是一個程式最基本的依賴組件,故將其註冊到IOC容器中,註冊logging有專門的擴展方法(AddLogging),而config沒有則直接使用通過的註冊方法(當然也可以基於ServiceCollection寫一個AddConfiguration擴展方法)
4.控制台需要一個核心的入口方法,用於處理核心業務,不要直接在Program中寫方法,這樣就不能使用IOC,同時也沒有做到職責分明,Program僅是程式啟動入口,業務處理應該有專門的入口,故上述代碼中有HostService類(即:核心宿主服務類, 意為存在於控制臺中的服務處理類,在這個類的構造涵數中列出所需依賴的服務組件,以便實例化時IOC可以自動註入這個參數),並註冊到IOC容器中,當然也可以先定義一個IHostService介面然後實現這個介面。(如果有多個HostService類實例,建議定義一個IHostService介面,介面中只需要入口方法定義即可,如:RunAsync)
5.當各組件初始化設置OK、IOC註冊到位後,就應該通過IOC解析獲得HostService類實例,並執行入口方法:RunAsync,該方法為非同步後臺執行,即調用該方法後,會在單獨的後臺線程處理核心業務,然後主線程繼續往下麵走,輸出關閉提示信息,最後的Console.ReadLine();很關鍵,這個是等待輸入流並掛起當前主線程,目的大家都知道,不要讓控制台程式關閉。
通過上述的講解及源代碼展示,有沒有感覺優雅呢?如果覺得這樣還算優雅,那下麵展示的第二種更優雅的姿勢
編寫.NET CORE控制台程式優雅姿勢二:(使用通用主機也稱泛型主機HostBuilder)
代碼如下:Program.cs
using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Hosting; using Microsoft.Extensions.Logging; using NLog.Extensions.Logging; using Microsoft.Extensions.Configuration; using System.IO; using Polly; using System; namespace NetCoreConsoleApp { class Program { static void Main(string[] args) { var host = new HostBuilder() .ConfigureHostConfiguration(configHost => { configHost.SetBasePath(Directory.GetCurrentDirectory()); }) .ConfigureAppConfiguration(configApp => { configApp.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true); }) .ConfigureServices((context, services) => { //添加數據訪問組件示例:services.AddTransient<IDbAccesser>(provider => //{ // string connStr = context.Configuration.GetConnectionString("ConnDbStr"); // return new SqlDapperEasyUtil(connStr); //}); //添加HttpClient封裝類示例:services.AddHttpClient<GitHubApiClient>() //.AddTransientHttpErrorPolicy(builder => builder.WaitAndRetryAsync(3, t => TimeSpan.FromMilliseconds(800))); services.AddHostedService<DemoHostedService>(); }) .ConfigureLogging((context, configLogging) => { configLogging.ClearProviders(); configLogging.SetMinimumLevel(LogLevel.Trace); configLogging.AddNLog(context.Configuration); }) .UseConsoleLifetime() .Build(); host.Run(); } } }
DemoHostedService類代碼:
using Microsoft.Extensions.Configuration; using Microsoft.Extensions.Hosting; using Microsoft.Extensions.Logging; using System; using System.Diagnostics; using System.Threading; using System.Threading.Tasks; namespace NetCoreConsoleApp { public class DemoHostedService : IHostedService { private readonly IConfiguration config; private readonly ILogger logger; public DemoHostedService(IConfiguration config, ILogger<DemoHostedService> logger) { this.config = config; this.logger = logger; } public Task StartAsync(CancellationToken cancellationToken) { Console.WriteLine(nameof(DemoHostedService) + "已開始執行..."); //TODO 業務邏輯代碼,如下模擬 Stopwatch stopwatch = Stopwatch.StartNew(); for (int i = 1; i <= 100; i++) { Console.WriteLine("test WriteLine:" + i); Thread.Sleep(100); } stopwatch.Stop(); logger.LogInformation("Logging - Execute Elapsed Times:{}ms", stopwatch.ElapsedMilliseconds); return Task.FromResult(0); } public Task StopAsync(CancellationToken cancellationToken) { Console.WriteLine(nameof(DemoHostedService) + "已被停止"); return Task.FromResult(0); } } }
因為要使用HostBuilder類及相關的.NET CORE組件(如上代碼主要使用到了:Host、Dapper、Nlog、Polly等),故仍需引用相關的NuGet包,詳細配置屬性如下:(項目文件csproj)
<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <OutputType>Exe</OutputType> <TargetFramework>netcoreapp2.2</TargetFramework> <RuntimeIdentifiers>win10-x64</RuntimeIdentifiers> <SelfContained>false</SelfContained> </PropertyGroup> <ItemGroup> <PackageReference Include="Dapper" Version="1.60.6" /> <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="2.2.0" /> <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.2.0" /> <PackageReference Include="Microsoft.Extensions.Hosting" Version="2.2.0" /> <PackageReference Include="Microsoft.Extensions.Http.Polly" Version="2.2.0" /> <PackageReference Include="NLog.Extensions.Logging" Version="1.5.1" /> <PackageReference Include="System.Collections.Concurrent" Version="4.3.0" /> </ItemGroup> <ItemGroup> <None Update="appsettings.json"> <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory> </None> <None Update="nlog.config"> <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory> </None> </ItemGroup> </Project>View Code
如上代碼所示,寫過ASP.NET CORE程式的人可能比較眼熟,這與ASP.NET CORE的寫法很類似,是的,你沒有看錯,HostBuilder是通用主機,是可以廣泛應用於非HTTP的環境下,而ASP.NET CORE中的WebHostBuilder 主要用於HTTP WEB環境,使用方式基本類似,都是先定義HostBuilder,然後利用擴展方法註冊、配置各種組件(中間件),最後調用Host的Run方法,開啟後臺服務執行,不同的是WebHostBuilder多了屬於HTTP專有的一些屬性及方法及其適用的中間件。
由於這種寫法比較通用,適用於已熟悉.NET CORE或ASP.NET CORE的人群,上手也較簡單,故建議採取這種方式來寫.NET CORE控制台程式。需要註意的是HostBuilder中最重要的是:註冊HostedService 服務,如上代碼中的DemoHostedService即是實現了IHostedService介面的宿主後臺服務類,可以定義多個,然後都註冊到IOC中,最後Host會按註冊先後順序執行多個HostedService服務的StartAsync方法,當停止時同樣會執行多個HostedService服務的StopAsync方法
下麵再來看看使用Spring&Spring Boot框架來優雅的編寫控制台程式
編寫Spring控制台程式優雅姿勢一:(只引用所必需的spring jar包、logger jar包,追求極簡風)
使用IDEA +MAVEN 創建一個quickstart 控制台項目,在maven POM XML中先引用所必需的spring jar包、logger jar包等,配置如下:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <artifactId>spring-console</artifactId> <name>spring-console</name> <!-- FIXME change it to the project's website --> <url>http://www.zuowenjun.cn</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <spring.version>5.1.8.RELEASE</spring.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.25</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.2.3</version> </dependency> </dependencies> <build> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle --> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-jar-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle --> <plugin> <artifactId>maven-site-plugin</artifactId> <version>3.7.1</version> </plugin> <plugin> <artifactId>maven-project-info-reports-plugin</artifactId> <version>3.0.0</version> </plugin> </plugins> </pluginManagement> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>8</source> <target>8</target> </configuration> </plugin> </plugins> </build> </project>View Code
然後採取自定義註解類(SpringBeansConfig)的方式註冊相關Bean(包含配置映射類Bean:AppProperties),代碼如下:
//app.java package cn.zuowenjun.spring; import cn.zuowenjun.spring.cn.zuowenjun.spring.services.HostService; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import java.io.IOException; /** * Hello world! */ public class App { public static void main(String[] args) { AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringBeansConfig.class); HostService hostService = applicationContext.getBean(HostService.class); hostService.run(); applicationContext.registerShutdownHook(); try { System.in.read(); } catch (IOException e) { System.out.println("等待讀取輸入數據報錯:" + e.getMessage() + ",將直接退出程式!"); } } } //AppProperties.java package cn.zuowenjun.spring; import org.springframework.beans.factory.annotation.Value; public class AppProperties { @Value("${app.name}") private String appName; @Value("${app.author}") private String appAuthor; @Value("${app.test.msg}") private String testMsg; public String getAppName() { return appName; } public void setAppName(String appName) { this.appName = appName; } public String getAppAuthor() { return appAuthor; } public void setAppAuthor(String appAuthor) { this.appAuthor = appAuthor; } public String getTestMsg() { return testMsg; } public void setTestMsg(String testMsg) { this.testMsg = testMsg; } } //SpringBeansConfig.java package cn.zuowenjun.spring; import cn.zuowenjun.spring.cn.zuowenjun.spring.services.HostService; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.PropertySource; import org.springframework.context.annotation.Scope; import org.springframework.core.annotation.Order; @Configuration @PropertySource(value = "classpath:app.properties", ignoreResourceNotFound = false) public class SpringBeansConfig { @Bean @Order(1) public HostService hostService() { return new HostService(); } @Bean @Order(0) @Scope("singleton") public AppProperties appProperties() { return new AppProperties(); } //註冊其它所需Bean... } //HostService.java package cn.zuowenjun.spring.cn.zuowenjun.spring.services; import cn.zuowenjun.spring.AppProperties; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.util.StopWatch; import java.util.Collections; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class HostService { private static final Logger LOGGER = LoggerFactory.getLogger(HostService.class); @Autowired private AppProperties appProperties; //可以添加其它屬性註入 public void run() { // ExecutorService pool = Executors.newSingleThreadExecutor(); // pool.execute(() -> execute()); new Thread(this::execute).start(); } /// <summary> /// 控制台核心執行入口方法 /// </summary> private void execute() { //TODO 業務邏輯代碼,如下模擬 StopWatch stopwatch = new StopWatch(); stopwatch.start(); for (int i = 1; i <= 100; i++) { System.out.println("test WriteLine:" + i); try { Thread.sleep(100); } catch (Exception e) { } } stopwatch.stop(); System.out.println(String.join("", Collections.nCopies(30, "="))); System.out.printf("app name is:%s %n", appProperties.getAppName()); System.out.printf("app author is:%s %n", appProperties.getAppAuthor()); System.out.printf("app test msg:%s %n", appProperties.getTestMsg()); LOGGER.info("Logging - Execute Elapsed Times:{}ms", stopwatch.getTotalTimeMillis()); } }
app.properties配置文件內容如下,註意應放在classpth目錄下(即:resources目錄下,沒有需自行創建並設為resources目錄):
app.name=demo spring console app.author=zuowenjun app.test.msg=hello java spring console app!
如上即上實現一個spring的控制台程式,當然由於是示例,故只引用了logger包,正常還需引用jdbc或ORM框架的相關jar包, 上述代碼關鍵邏輯說明(同樣要註意順序):
1.new AnnotationConfigApplicationContext類(spring IOC容器),創建一個IOC容器,類似.NET CORE中的ServiceProvider類;
2.定義 SpringBeansConfig bean註冊配置類(註冊相關依賴),這個類中依次註入相關的bean,如果bean之間有依賴順序關係,建議添加@Order並指明序號;該類作為AnnotationConfigApplicationContext的構造函數參數傳入,以便IOC自動解析並完成實際註冊;
3.同樣是定義一個HostService 宿主服務類,並實現run方法邏輯,一般採取後臺線程非同步執行,為了演示效果與.NET CORE的HostService 類相同,示例邏輯基本相同。另外還定義了AppProperties配置映射類,便於直接讀取配置,.NET CORE同樣也有類似註冊bind到配置類中,然後在服務類中使用:IOptions<配置類>作為構造函數參數實現構造函數註入。只是由於篇幅有限故.NET CORE部份直接採取了註入IConfiguration,大家有興趣可以查看網上相關資料。
4.IOC容器初始化並註冊成功後,即可解析HostService 類獲得實例,執行run方法,run方法會開啟線程在後臺處理,並返回到主線程,直至in.read()阻塞掛起主線程,防止程式自動關閉。
編寫Spring boot控制台程式優雅姿勢二:(引用spring boot jar包)
使用IDEA+Spring Initializr來創建一個spring boot項目,創建過程中按需選擇依賴的框架,我這裡是示例,故除了預設spring-boot-starter依賴外,其餘什麼依賴都不添加,創建後Maven POM XML如下:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.6.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>cn.zuowenjun.spring</groupId> <artifactId>springboot-console</artifactId> <version>0.0.1-SNAPSHOT</version> <name>springboot-console</name> <description>Demo project for Spring Boot</description> <url>http://www.zuowenjun.cn</url> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>View Code
然後創建相關的Bean類:HostService(宿主服務類,這個與前文定義類均相同)、AppProperties(配置映射類,這個是映射預設的application.properties配置文件,註意這裡的映射方式與前文所描述稍有不周,採用:@ConfigurationProperties+屬性映射,無需加@Value註解,映射屬性時如果有-則應寫成駝峰式,如果有.則應定義內部靜態類,呈現層級屬性完成映射,具體的用法可以參見我之前的文章):
//HostService.java package cn.zuowenjun.spring.services; import cn.zuowenjun.spring.AppProperties; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.util.StopWatch; import java.util.Collections; @Component public class HostService { private static final Logger LOGGER = LoggerFactory.getLogger(HostService.class); @Autowired private AppProperties appProperties; //可以添加其它屬性註入 public void run() { // ExecutorService pool = Executors.newSingleThreadExecutor(); // pool.execute(() -> execute()); new Thread(this::execute).start(); } /// <summary> /// 控制台核心執行入口方法 /// </summary> private void execute() { //TODO 業務邏輯代碼,如下模擬 StopWatch stopwatch = new StopWatch(); stopwatch.start(); for (int i = 1; i <= 100; i++) { System.out.println("test WriteLine:" + i); try { Thread.sleep(100); } catch (Exception e) { } } stopwatch.stop(); System.out.println(String.join("", Collections.nCopies(30, "="))); System.out.printf("app name is:%s %n", appProperties.getName()); System.out.printf("app author is:%s %n", appProperties.getAuthor()); System.out.printf("app test msg:%s %n", appProperties.getTestMsg()); LOGGER.info("Logging - Execute Elapsed Times:{}ms", stopwatch.getTotalTimeMillis()); } } //AppProperties.java package cn.zuowenjun.spring; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.stereotype.Component; @Component @ConfigurationProperties(prefix = "app") public class AppProperties { private String name; private String author; private String testMsg; public String getName() { return name; }