编程语言Spring Native实战(畅快体验79毫秒启动springboot应用)
编程语言Spring Native实战(畅快体验79毫秒启动springboot应用)欢迎访问我的GitHubhttps://github.com/zq2599/blog_demos内容：所有原创文章分类汇总及配套源码，涉及Java、Docker、Kubernetes、DevOPS等；关于Spring NativeSpring官方博客于2021年03月11日宣布Spring Native的beta版本发布，借助Spring Native可以将spring应用与GraalVM集成到native image中；native image是GraalVM的一项技术，会将java应用的字节码编译成可执行文件，还会与JDK的本地库做静态链接，运行应用时无需Java虚拟机，自身已集成了内存管理，线程调度等能力，更多信息请参考：https://www.graalvm.org/reference-manual/native-image/本文以实战为主，因此不会用太多篇幅介绍Spring Native的理论和优势，这里简单小结几个重要特性：应用启动速度不超过100毫秒；启动即达到性能峰值（C1、C2等手段已经用不上了）运行时更低的内存消耗；docker镜像不含JDK（所需文件已经抽取出来放入镜像），官方展示的含有Spring Boot, Spring MVC, Jackson, Tomcat的镜像大小是50M；为了达到前面的效果，代价是构建时间更长；Spring Native到底是什么个人的理解：Spring Native是Spring提供的、制作native image的技术方案，涉及到以下关键技术：Spring ahead-of-time (AOT) 插件，对spring应用做AOT处理，使得传统虚拟机的class lazy loading在不复存在；spring-boot-maven-plugin插件在构建docker镜像的时候，使用了名为dmikusa/graalvm-tiny的镜像作为构建工具，这个工具负责将当前工程的构建结果和GraalVM集成在一起，最终制作成native image；本篇概览作为实战风格的文章，本篇主要内容是开发springboot应用再构建为native image，然后验证其功能和效果，本文由以下内容构成：环境信息新建名为spring-native-tutorials的maven父工程，对实战用到的依赖库、插件等做统一配置；新建名为webmvc的maven子工程，这是个springboot应用；将webmvc构建为native image，这是个docker镜像；在docker中启动镜像，验证是否可用，并检查相关相关指标；环境信息本次实战相关的环境信息如下：电脑：MacBook pro 13寸 2018操作系统：macOS Big Sur 11.2.3IDE：IntelliJ IDEA 2018.3.5 (Ultimate Edition)docker：20.10.5JDK：1.8.0_211maven：3.6.0springboot：2.5.0-SNAPSHOTspring-aot-maven-plugin：0.10.0-SNAPSHOT源码下载本篇实战中的完整源码可在GitHub下载到，地址和链接信息如下表所示(https://github.com/zq2599/blog_demos)：名称链接备注项目主页https://github.com/zq2599/blog_demos该项目在GitHub上的主页git仓库地址(https)https://github.com/zq2599/blog_demos.git该项目源码的仓库地址，https协议git仓库地址(ssh)git@github.com:zq2599/blog_demos.git该项目源码的仓库地址，ssh协议这个git项目中有多个文件夹，本次实战的源码在spring-native-tutorials文件夹下，如下图红框所示：
新建名为spring-native-tutorials的maven父工程对Spring Native的学习不是写出helloworld就完事，因此这里先创建一个父工程，为今后所有的应用提供统一的依赖库、插件管理；新建名为spring-native-tutorials的maven父工程，pom.xml内容如下，有几处要注意的地方稍后提到：<?xml version="1.0" encoding="UTF-8"?>4.0.0webmvcorg.springframework.bootspring-boot-starter-parent2.5.0-SNAPSHOTcom.bolingcavalryspring-native-tutorials1.0-SNAPSHOTpom1.8dmikusa/graalvm-tiny2020.0.2spring-releaseSpring releasehttps://repo.spring.io/releasefalsespring-milestoneSpring milestonehttps://repo.spring.io/milestonefalsespring-snapshotSpring Snapshotshttps://repo.spring.io/snapshotfalsespring-releaseSpring releasehttps://repo.spring.io/releasefalsespring-milestoneSpring milestonehttps://repo.spring.io/milestonefalsespring-snapshotSpring Snapshotshttps://repo.spring.io/snapshotfalseorg.springframework.experimentalspring-native0.10.0-SNAPSHOTorg.springframework.cloudspring-cloud-dependencies${spring-cloud.version}pomimportorg.springframework.bootspring-boot-maven-plugin${classifier} ${builder}true${native.build.args}IF_NOT_PRESENTorg.springframework.experimentalspring-aot-maven-plugin0.10.0-SNAPSHOTtest-generatetest-generategenerategenerate上述pom.xml有以下几处需要注意：插件仓库、依赖库仓库、依赖库版本的配置都集中在这里；配置好spring-aot-maven-plugin和spring-boot-maven-plugin这两个插件，子工程会用到；spring-boot-maven-plugin插件制作docker镜像的时候，又会用到dmikusa/graalvm-tiny镜像，这才是真正构建native image的工具；新建springboot类型的maven子工程新建名为webmvc的子工程，pom.xml内容如下，可见内容很简单，就是常规依赖库和父工程配置的两个插件，一个负责执行AOT，一个负责构建镜像：<?xml version="1.0" encoding="UTF-8"?>spring-native-tutorialscom.bolingcavalry1.0-SNAPSHOT4.0.0webmvcorg.springframework.experimentalspring-nativeorg.springframework.bootspring-boot-starter-weborg.apache.tomcat.embedtomcat-embed-coreorg.apache.tomcat.embedtomcat-embed-websocketorg.apache.tomcat.experimentaltomcat-embed-programmatic${tomcat.version}org.springframework.bootspring-boot-starter-testtestorg.springframework.experimentalspring-aot-maven-plugintrueorg.springframework.bootspring-boot-maven-plugin代码很简单，一个普通的springboot应用，带http接口：package com.bolingcavalry.webmvc;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.http.HttpStatus;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.ResponseStatus;import org.springframework.web.bind.annotation.RestController;import java.time.LocalDateTime;@SpringBootApplication@RestControllerpublic class WebmvcApplication {public static void main(String[] args) {SpringApplication.run(WebmvcApplication.class, args);}@ResponseStatus(HttpStatus.ACCEPTED)@GetMapping("/status")public String status() {return "status";}@GetMapping("/")public String hello() {return "1. Hello from Spring MVC and Tomcat, " + LocalDateTime.now();}}现在编码已完成，来构建docker镜像吧，进入父工程的pom.xml所在目录，执行以下命令：mvn clean -U -DskipTests spring-boot:build-image构建成功后输出信息如下（篇幅所限仅截取最后一小段）,耗时4分25秒，期间笔记本风扇狂转：...[INFO] Successfully built image 'docker.io/library/webmvc:1.0-SNAPSHOT'[INFO] [INFO] ------------------------------------------------------------------------[INFO] Reactor Summary for spring-native-tutorials 1.0-SNAPSHOT:[INFO] [INFO] spring-native-tutorials ............................ SUCCESS [ 1.786 s][INFO] webmvc ............................................. SUCCESS [04:19 min][INFO] ------------------------------------------------------------------------[INFO] BUILD SUCCESS[INFO] ------------------------------------------------------------------------[INFO] Total time: 04:25 min[INFO] Finished at: 2021-05-22T16:36:44+08:00[INFO] ------------------------------------------------------------------------[WARNING] The requested profile "nexus" could not be activated because it does not exist.执行docker images命令，如下图，可见镜像已经生成：
查看镜像构成，可见每个layer都不大，共计七十多M：(base) zhaoqindeMBP:~ zhaoqin$ docker history webmvc:1.0-SNAPSHOTIMAGE CREATED CREATED BY SIZE COMMENTb8ff54813ae0 41 years ago 69B41 years ago 452kB41 years ago 2.51MB41 years ago 57.2MB41 years ago 1.4MB41 years ago 268B41 years ago 17.3MB镜像构建成功，可以验证基本功能了；验证执行以下命令，创建一个临时容器（控制台结束后容器会被清理掉）：docker run --rm -p 8080:8080 webmvc:1.0-SNAPSHOT控制台输出如下，79毫秒启动完成，真是一眨间的功夫：(base) zhaoqindeMBP:~ zhaoqin$ docker run --rm -p 8080:8080 webmvc:1.0-SNAPSHOT2021-05-22 09:34:57.578 INFO 1 --- [ main] o.s.nativex.NativeListener : This application is bootstrapped with code generated with Spring AOT . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.5.0-SNAPSHOT)2021-05-22 09:34:57.586 INFO 1 --- [ main] c.b.webmvc.WebmvcApplication : Starting WebmvcApplication using Java 1.8.0_292 on 3529ec458896 with PID 1 (/workspace/com.bolingcavalry.webmvc.WebmvcApplication started by cnb in /workspace)2021-05-22 09:34:57.586 INFO 1 --- [ main] c.b.webmvc.WebmvcApplication : No active profile set, falling back to default profiles: default2021-05-22 09:34:57.661 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)May 22, 2021 9:34:57 AM org.apache.coyote.AbstractProtocol initINFO: Initializing ProtocolHandler ["http-nio-8080"]May 22, 2021 9:34:57 AM org.apache.catalina.core.StandardService startInternalINFO: Starting service [Tomcat]May 22, 2021 9:34:57 AM org.apache.catalina.core.StandardEngine startInternalINFO: Starting Servlet engine: [Apache Tomcat/9.0.46]May 22, 2021 9:34:57 AM org.apache.catalina.core.ApplicationContext logINFO: Initializing Spring embedded WebApplicationContext2021-05-22 09:34:57.669 INFO 1 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 79 msMay 22, 2021 9:34:57 AM org.apache.coyote.AbstractProtocol startINFO: Starting ProtocolHandler ["http-nio-8080"]2021-05-22 09:34:57.713 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''2021-05-22 09:34:57.713 INFO 1 --- [ main] c.b.webmvc.WebmvcApplication : Started WebmvcApplication in 0.178 seconds (JVM running for 0.19)2021-05-22 09:34:57.713 INFO 1 --- [ main] o.s.b.a.ApplicationAvailabilityBean : Application availability state LivenessState changed to CORRECT2021-05-22 09:34:57.714 INFO 1 --- [ main] o.s.b.a.ApplicationAvailabilityBean : Application availability state ReadinessState changed to ACCEPTING_TRAFFIC浏览器访问本机8080端口，如下图，应用基本功能正常：
再看看资源使用情况，命令是docker stats，如下可见，内存仅用了30M：CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS6ce6c66fb4de jovial_hertz 0.11% 30.69MiB / 3.844GiB 0.78% 1.49kB / 158B 4.31MB / 0B 18我曾经在hub.docker.com上放了一个传统springboot应用制作的镜像bolingcavalry/hellojib:0.0.1-SNAPSHOT，现在拿来和Spring Native镜像对比一下，启动信息如下，耗时2036毫秒：(base) zhaoqindeMacBook-Pro:~ zhaoqin$ docker run --rm -P docker.io/bolingcavalry/hellojib:0.0.1-SNAPSHOT . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.1.6.RELEASE)2021-05-22 11:13:28.121 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : Starting HellojibApplication on ffb32e5b68b9 with PID 1 (/app/classes started by root in /)2021-05-22 11:13:28.128 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : No active profile set, falling back to default profiles: default2021-05-22 11:13:30.000 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)2021-05-22 11:13:30.054 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]2021-05-22 11:13:30.054 INFO 1 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.21]2021-05-22 11:13:30.241 INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext2021-05-22 11:13:30.241 INFO 1 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 2036 ms2021-05-22 11:13:30.715 INFO 1 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'2021-05-22 11:13:31.103 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''2021-05-22 11:13:31.110 INFO 1 --- [ main] c.b.hellojib.HellojibApplication : Started HellojibApplication in 3.618 seconds (JVM running for 4.297)2021-05-22 11:13:48.866 INFO 1 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'2021-05-22 11:13:48.866 INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'2021-05-22 11:13:48.880 INFO 1 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 14 ms再用docker stats对比内存，传统springboot应用的容器消耗了三百多兆内存：CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDSffb32e5b68b9 eager_williamson 0.64% 356.3MiB / 3.844GiB 9.05% 3.46kB / 2.29kB 0B / 0B 316ce6c66fb4de jovial_hertz 0.11% 30.69MiB / 3.844GiB 0.78% 1.49kB / 158B 4.31MB / 0B 18综上所述，Spring Native带来的优势是很明显的，不过请注意：2021年03月11日官方宣布的Spring Native只是beta版本，请不要用于生产环境！！！下载插件失败在实际操作过程中，经常会遇到maven插件或者docker镜像下载失败的情况，除了多试几次，您还可以考虑将项目放到github上去，借助github action在云端完成镜像构建，具体操作请参考《用GitHub Actions制作Docker镜像》不用开发，直接体验我已将镜像上传到hub.docker.com，完整名称是bolingcavalry/webmvc:1.0-SNAPSHOT，如果您只想体验一下native image的效果可以直接下载该镜像使用；你不孤单，欣宸原创一路相伴Java系列Spring系列Docker系列kubernetes系列数据库+中间件系列DevOps系列欢迎关注公众号：程序员欣宸www.somanba.cnwww.jcdi.cnwww.sobd.cc