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文章目录

前言

基于 JVM 的应用启动比原生应用慢一拍
运行期间性能不差，启动笨重一点又怎么样？

环境准备

本文环境概览
准备 GraalVM

初尝 GraalVM 的 Native Image

GraalVM 这名字听起来像是新研发的虚拟机？
hello, world 的 Native Image

native-image 使用方法
构建 hello, world
关于 NativeImageBuildServer 与构建过程资源占用

Native Image 使用没有限制吗？肯定有

动态类加载、反射、动态代理、JNI、JCA 等特性在部分场景需要配置

已知类的反射可以正常执行

封闭优化不支持的特性

invokedynamic（部分支持）
Serialization（序列化，需要通过配置才能支持）
Security Manager（安全管理）

部分特性在 SVM 的实现会有所差异

Class Initializers
不再调用 finalize() 方法
SVM 未实现 java.lang.Thread 中的废弃方法
Unsafe 相关

尝试构建 Spring Boot 项目的 Native Image

默认参数构建出 Fallback Image
指定不使用 Fallback Image
指定运行时才报告错误
基于 class 文件和指定 classpath 构建 Native Image

Quarkus - Supersonic Subatomic Java

称为 “超声波 Java” 的 Quarkus 有什么特性？

CONTAINER FIRST（容器优先）
UNIFIES IMPERATIVE AND REACTIVE（统一命令式和响应式编程）
DEVELOPER JOY（开发者友好）
BEST OF BREED LIBRARIES AND STANDARDS（基于最好的库和标准）

说这么多，不如试试

初始化 Quarkus 项目
数据库准备
基于 Spring 体系的 CRUD 代码
在 Dev 模式运行验证

dev 模式下支持 Hot Reload

构建 Native Image

参考资料

前言

基于 JVM 的应用启动比原生应用慢一拍

平时 Java 用得比较多，也会用 Golang 或者 C 等静态编译语言的人，应该多少都会感觉到，即使是最简单的 hello, world，Java 程序的启动速度相比静态编译出的可执行程序会慢上一拍。
如果使用 Java 等语言实现的运行在 JVM 上的 CLI 工具，这种慢一拍的感觉应该会更明显（使用过 RocketMQ 的 mqadmin 脚本的同学应该有所体会）。
Spring Framework 全家桶的启动就更不用说了，大项目启动时间可达分钟级别……

先来个简单的实验：

一段 Java 的 hello, world

public class Main {public static void main(String[] args) {System.out.println("hello, java");}
}

一段 Golang 的 hello, world

package main
func main() {println("hello, go")
}

➜  ~ go build main.go
➜  ~ repeat 10 time ./main
hello, go
./main  0.00s user 0.00s system 107% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 118% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 110% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 109% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 112% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 119% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 109% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 108% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 106% cpu 0.001 total
hello, go
./main  0.00s user 0.00s system 107% cpu 0.001 total➜  ~ javac Main.java      
➜  ~ repeat 10 time java Main
hello, java
java Main  0.07s user 0.04s system 119% cpu 0.087 total
hello, java
java Main  0.07s user 0.02s system 115% cpu 0.074 total
hello, java
java Main  0.06s user 0.01s system 114% cpu 0.063 total
hello, java
java Main  0.06s user 0.01s system 146% cpu 0.046 total
hello, java
java Main  0.06s user 0.01s system 147% cpu 0.049 total
hello, java
java Main  0.05s user 0.02s system 142% cpu 0.046 total
hello, java
java Main  0.05s user 0.01s system 143% cpu 0.045 total
hello, java
java Main  0.05s user 0.01s system 142% cpu 0.045 total
hello, java
java Main  0.05s user 0.02s system 144% cpu 0.045 total
hello, java
java Main  0.05s user 0.01s system 142% cpu 0.045 total

Golang 写的 hello, world 基本是 敲下键盘那一刻就已经运行完毕退出了，Java 写的 hello, world 运行时间人类可以感受到，尤其是冷启动（首次启动 JVM 进程，可能长达数百毫秒。在树莓派这类硬件上，JVM 冷启动可长达数秒）。

运行期间性能不差，启动笨重一点又怎么样？

基于 JVM 的应用确实需要一定的启动时间（尤其是 Spring），启动内存相比原生应用也不低。“速度慢，吃内存” 成了大家黑 Java 的关键点。

不过，在目前常见的架构下，这些问题不会特别突出：

在应用运行期间，因 JVM 的各种优化手段，应用的运行性能会逐渐优化，不会比原生应用差。
在内存方面，JVM 所需内存对于一般服务器也没有什么压力。
启动慢的问题，在有滚动发布机制的环境中，应用多花一点时间进入就绪状态也没什么问题。

这么看来其实 “速度慢，吃内存” 也不是什么问题。

但是， 脱离场景谈技术都是耍流氓 。

对于一些用户群体比较确定、不会有突发流量，充分评估过资源需求、本身比较稳定的应用，启动时间和内存占用一般不会有什么问题。

但是对于弹性计算、存在突发流量等需要时刻准备水平扩容的场景，JVM 的短板就被放大了。

例如基于事件驱动的函数计算，按需分配资源，不用的时候不占用资源。不预留实例的函数计算，只有事件发生的时候才会分配资源并创建实例。

从以下三个方面谈 JVM 的短板：

在启动时间方面：
如果函数实例是后台计算等不涉及用户体验的操作，实例启动慢一点影响不会很大。
但如果函数提供的服务具有即时性、涉及用户体验、对时间敏感，实例启动时间就会在很大程度上影响着用户体验。原生应用和 JVM 相比，本身就没有启动的过程（本人的理解，从另一个角度说，操作系统的启动就是原生应用的启动）。因应用经过静态编译，业务逻辑的启动一般也不会占用太多时间（除非涉及 I/O 等对于 CPU 来说很慢的操作）。
在内存占用方面：
例如使用阿里云函数计算服务，内存需求关系到费用问题。一般虚拟机和原生应用相比在内存占用方面没有优势。一段相同逻辑的代码分别使用虚拟机和原生应用运行，虚拟机内存需求一般不会低于原生应用。
在运行期间：
JVM 有很多优化手段，基于 JVM 的应用经过时间的推移或者主动进行预热，可能会越来越快。但是，在弹性计算这类场景中，JVM 可能根本来不及优化，实例就已经被释放了。没有经过优化的 JVM 应用在运行速度上很难和原生应用的机器语言匹敌。

所以，回答标题的问题：

在现在这种新架构、新技术百花齐放的时代，如果 JVM 相关技术栈不能与时俱进，将很容易被后来者蚕食。

环境准备

本文环境概览

有条件的建议在 Linux 进行，Windows 上进行可能坑会稍多。
Environment

准备 GraalVM

GraalVM 可以在 Oracle 官网下载：https://www.oracle.com/downloads/graalvm-downloads.html?selected_tab=20l
注意版本的选择！

国内网络环境下载速度可能较慢，此处提供本人在用的版本：

GraalVM EE Linux 20.1.0 https://wuweijie.oss-cn-shenzhen.aliyuncs.com/resources/graalvm-ee-java11-linux-amd64-20.1.0.tar.gz
GraalVM EE Native Image Linux 20.1.0 组件离线安装包 （下载免C币） https://download.csdn.net/download/wu_weijie/12490465

GraalVM 的安装使用和普通的 JDK 没有区别，下载后解压并设置环境变量就可以了。

GraalVM 相比普通的 OpenJDK / Oracle JDK 增加了一些命令，例如用于管理 GraalVM 组件的命令 gu。

不要忘记安装 Native Image 组件！可以通过 gu 命令安装提前下载好 Native Image 组件的 jar。
Native Image 组件安装文档：https://docs.oracle.com/en/graalvm/enterprise/20/guide/reference/native-image.html

➜  ~ javac -version
javac 11.0.7➜  ~ java -version 
java version "11.0.7" 2020-04-14 LTS
Java(TM) SE Runtime Environment GraalVM EE 20.1.0 (build 11.0.7+8-LTS-jvmci-20.1-b02)
Java HotSpot(TM) 64-Bit Server VM GraalVM EE 20.1.0 (build 11.0.7+8-LTS-jvmci-20.1-b02, mixed mode, sharing)➜  ~ native-image 
Please specify options for native-image building or use --help for more info.

环境基本准备好了！

使用 Native Image 可能还需要 gcc 等开发工具，各环境所需依赖可以参考 Quarkus 文档：
https://quarkus.io/guides/building-native-image#prerequisites

初尝 GraalVM 的 Native Image

除了 Native Image，GraalVM 还有很多黑科技。篇幅有限，本文只关注 Native Image。

官网：https://www.graalvm.org/

GraalVM 这名字听起来像是新研发的虚拟机？

Download
根据官网的下载页面，其实 GraalVM 就是基于 OpenJDK / Oracle JDK 构建的，并不是什么新的虚拟机，本身还是 HotSpot VM，现有的项目可以将虚拟机直接切换 GraalVM。

要说新研发的虚拟机，本人根据资料理解，构建好的原生应用中的 SubstrateVM (SVM) 就是一个新的虚拟机（SVM 系列还包含了 AOT 等工具）。

hello, world 的 Native Image

native-image 使用方法

native-image 命令的帮助信息节选：

➜  hello-graalvm $GRAALVM_HOME/bin/native-image --helpGraalVM native-image building toolThis tool can be used to generate an image that contains ahead-of-time compiled Java code.Usage: native-image [options] class [imagename] [options](to build an image for a class)or  native-image [options] -jar jarfile [imagename] [options](to build an image for a jar file)

可以看到，native-image 命令参数接受类的字节码文件或 jar ，我们直接将文章前言部分通过 javac 编译的 Main.class 拿来用。

构建 hello, world

此处写的是 Main 而不是 Main.class，指定生成的可执行程序名为 main_native。

➜  hello-graalvm $GRAALVM_HOME/bin/native-image Main main_native
Build on Server(pid: 29364, port: 34701)*
[main_native:29364]    classlist:     987.61 ms,  0.96 GB
[main_native:29364]        (cap):     590.98 ms,  0.96 GB
[main_native:29364]        setup:   2,064.60 ms,  0.96 GB
[main_native:29364]     (clinit):      99.22 ms,  1.21 GB
[main_native:29364]   (typeflow):   3,109.82 ms,  1.21 GB
[main_native:29364]    (objects):   3,299.24 ms,  1.21 GB
[main_native:29364]   (features):     177.67 ms,  1.21 GB
[main_native:29364]     analysis:   6,857.44 ms,  1.21 GB
[main_native:29364]     universe:     199.91 ms,  1.21 GB
[main_native:29364]      (parse):     518.11 ms,  1.21 GB
[main_native:29364]     (inline):   1,130.87 ms,  1.66 GB
[main_native:29364]    (compile):   7,976.54 ms,  3.15 GB
[main_native:29364]      compile:  10,090.57 ms,  3.15 GB
[main_native:29364]        image:     636.62 ms,  3.15 GB
[main_native:29364]        write:     176.02 ms,  3.15 GB
[main_native:29364]      [total]:  21,153.23 ms,  3.15 GB

以上是构建 Native Image 过程中的输出，4列信息分别代表：

目标 Native Image 名称与 NativeImageBuildServer 的 Pid
构建步骤
步骤耗时
NativeImageBuildServer 的堆大小（数值比 top 命令监控到的内存稍小，本人猜测是堆大小）

构建完成后，目录中会有一个 main_native 可执行文件，重复执行 10 次：

➜  hello-graalvm ll ?ain*
-rwxr-xr-x 1 sia sia 1.2M 6月   2 22:30 main
-rw-r--r-- 1 sia sia  413 6月   2 23:18 Main.class
-rw-r--r-- 1 sia sia   51 6月   2 22:21 main.go
-rw-r--r-- 1 sia sia  104 6月   2 23:18 Main.java
-rwxr-xr-x 1 sia sia 8.1M 6月   6 10:53 main_native➜  hello-graalvm repeat 10 time ./main_native
hello, java
./main_native  0.00s user 0.00s system 94% cpu 0.009 total
hello, java
./main_native  0.00s user 0.01s system 91% cpu 0.008 total
hello, java
./main_native  0.00s user 0.01s system 88% cpu 0.006 total
hello, java
./main_native  0.00s user 0.00s system 94% cpu 0.004 total
hello, java
./main_native  0.00s user 0.00s system 92% cpu 0.003 total
hello, java
./main_native  0.00s user 0.00s system 93% cpu 0.002 total
hello, java
./main_native  0.00s user 0.00s system 91% cpu 0.002 total
hello, java
./main_native  0.00s user 0.00s system 87% cpu 0.002 total
hello, java
./main_native  0.00s user 0.00s system 91% cpu 0.002 total
hello, java
./main_native  0.00s user 0.00s system 93% cpu 0.002 total

对比一下前言中的实验结果，native-image 构建出来的 “hello, world” 可执行程序启动速度明显比通过 JVM 运行快很多，也达到了 ”敲下键盘那一刻已经运行完毕并退出” 的境界。

关于 NativeImageBuildServer 与构建过程资源占用

➜  hello-graalvm jps -mlvV | grep 29364 
29364 com.oracle.svm.hosted.server.NativeImageBuildServer -port=0 -logFile=/home/sia/.native-image/machine-id-ced39042e1ef44249ce6b3f25738a0e8/session-id-58f6/server-id-c54e3f0f73a1cc48d8cb58b05946a06b73cb841f608d5a7f9e62c46e06da98b438a2317d2bc2fcff22466f6a8846ce5cf572ac3413fb36f93e5238d3785da173/server.log -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCIProduct -XX:-UnlockExperimentalVMOptions -XX:ThreadPriorityPolicy=1 -XX:+UseParallelGC -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -Dtruffle.TrustAllTruffleRuntimeProviders=true -Dtruffle.TruffleRuntime=com.oracle.truffle.api.impl.DefaultTruffleRuntime -Dgraalvm.ForcePolyglotInvalid=true -Dgraalvm.locatorDisabled=true -Dsubstratevm.IgnoreGraalVersionCheck=true -Djava.lang.invoke.stringConcat=BC_SB --add-exports=jdk.internal.vm.ci/jdk.vm.ci.runtime=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.code=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.aarch64=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.amd64=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.meta=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.hotspot=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.services=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.common=ALL-UNNAMED --add-exports=jdk.internal.vm.ci/jdk.vm.ci.code.site=ALL-UNNAMED --add-e

通过 jps 命令可以看到，native-image 会启动一个 NativeImageBuildServer 用于构建可执行程序。可执行程序构建完成后，该 Server 仍驻留，下次构建将使用该实例（再次构建同样的可执行程序耗时与内存 [main_native_2:29364] [total]: 14,191.21 ms, 4.55 GB，耗时更少，但内存占用有所增加）

在另一个 Session 中启动的 top 命令，每 1 秒采集一次 graalvm 相关进程的运行状况。

➜  hello-graalvm top -d 1 -n60 -c | grep graalvm
29183 sia       20   0 32.264g 0.083g 0.014g S  27.6  0.1   0:00.29 /usr/local/graalvm-ee-java11-20.1.0/bin/native-i+ 
29364 sia       20   0 48.938g 0.078g 0.041g S  26.7  0.1   0:00.28 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.055g 0.546g 0.071g S 576.7  0.9   0:06.22 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.021g 0.638g 0.072g S 298.0  1.0   0:09.26 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.024g 0.663g 0.073g S 377.7  1.1   0:13.15 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29183 sia       20   0 32.264g 0.083g 0.014g S   1.0  0.1   0:00.30 /usr/local/graalvm-ee-java11-20.1.0/bin/native-i+ 
29364 sia       20   0 51.571g 0.802g 0.074g S 534.0  1.3   0:18.65 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.573g 0.856g 0.074g S 720.6  1.4   0:26.00 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.576g 0.922g 0.074g S 493.3  1.5   0:31.13 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.576g 0.923g 0.074g S 302.9  1.5   0:34.25 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.576g 0.988g 0.075g S 281.4  1.6   0:37.12 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 51.576g 1.055g 0.075g S 135.0  1.7   0:38.51 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 52.371g 1.147g 0.075g S 223.3  1.8   0:40.81 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.238g 1.311g 0.075g S 823.5  2.1   0:49.21 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.240g 1.315g 0.075g S 770.5  2.1   0:57.30 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.243g 1.660g 0.075g S 989.3  2.6   1:07.49 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.243g 1.762g 0.075g S 982.1  2.8   1:17.90 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.245g 1.864g 0.075g S  1024  3.0   1:28.75 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.246g 2.331g 0.075g S  1003  3.7   1:39.38 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.248g 2.337g 0.075g S 867.0  3.7   1:48.57 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.248g 2.366g 0.075g S  1030  3.8   1:59.18 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.250g 2.940g 0.075g S 917.3  4.7   2:09.27 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.252g 3.211g 0.075g S 516.5  5.1   2:14.59 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.155g 3.272g 0.075g S 408.7  5.2   2:18.80 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+ 
29364 sia       20   0 53.155g 3.273g 0.075g S   0.9  5.2   2:18.81 /usr/local/graalvm-ee-java11-20.1.0/bin/java -cp+

第 9, 10 列分别是 CPU 和内存利用率。（CPU 利用率是每个逻辑核心利用率的和，理论上 12T 的 CPU 最高利用率为 1200）
本来我以为执行 native-image 就和 go build 差不多，没想到，本次构建的只是一个 hello, world，就已经占用了大量计算资源和近 3.3G 内存，这是一个不低的门槛。（剧透一下，Quarkus 构建可执行程序的占用资源会高很多）

Native Image 使用没有限制吗？肯定有

既然要做静态分析编译，肯定有所牺牲。

文档：https://github.com/oracle/graal/blob/master/substratevm/LIMITATIONS.md

动态类加载、反射、动态代理、JNI、JCA 等特性在部分场景需要配置

以反射为例：
Java 和 Go 都有反射 (Reflection)，使用过的人应该清楚，Go 的反射能力相比 Java 的反射能力有所差距（例如 Go 不能直接办到 Java 的 Class.forName()）。

如果构建 Native Image，Class.forName() 等方法在一些场景下（例如从外部获取或动态编译代码等，无法在 native-image 构建期间分析的代码）需要提供配置文件指定一些信息。（这块资料较少）

配置相关资料：

https://github.com/oracle/graal/blob/master/substratevm/CONFIGURE.md
https://github.com/oracle/graal/blob/master/substratevm/REFLECTION.md

已知类的反射可以正常执行

来一个简单的示例，动态加载 java.lang.Integer 并获取 MAX_VALUE 的值：

NativeImageReflection.java

package vip.wuweijie.test.graalvm;/*** @author wuweijie*/
public class NativeImageReflection {public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {System.out.println(Class.forName("java.lang.Integer").getField("MAX_VALUE").get(null));}
}

编译为 class 后用 java 直接运行：

➜  classes java vip.wuweijie.test.graalvm.NativeImageReflection 
2147483647

构建可执行程序并运行：

➜  classes $GRAALVM_HOME/bin/native-image vip.wuweijie.test.graalvm.NativeImageReflection reflect
Build on Server(pid: 29364, port: 34701)
[reflect:29364]    classlist:      90.08 ms,  5.13 GB
[reflect:29364]        (cap):     280.83 ms,  5.13 GB
[reflect:29364]        setup:     618.75 ms,  5.13 GB
[reflect:29364]     (clinit):     102.93 ms,  5.13 GB
[reflect:29364]   (typeflow):   2,906.36 ms,  5.13 GB
[reflect:29364]    (objects):   3,788.48 ms,  5.13 GB
[reflect:29364]   (features):     146.51 ms,  5.13 GB
[reflect:29364]     analysis:   7,128.26 ms,  5.13 GB
[reflect:29364]     universe:     185.85 ms,  5.13 GB
[reflect:29364]      (parse):     318.00 ms,  5.13 GB
[reflect:29364]     (inline):     447.50 ms,  5.13 GB
[reflect:29364]    (compile):   4,994.34 ms,  5.20 GB
[reflect:29364]      compile:   6,114.72 ms,  5.20 GB
[reflect:29364]        image:     545.57 ms,  5.20 GB
[reflect:29364]        write:     124.16 ms,  5.20 GB
[reflect:29364]      [total]:  14,853.08 ms,  5.20 GB➜  classes ./reflect     
2147483647

封闭优化不支持的特性

invokedynamic（部分支持）

通过 javac 生成的 invokedynamic 仍然可以支持，例如 Lambda 和 String 拼接等。

Serialization（序列化，需要通过配置才能支持）

影响范围可能涉及到 java.rmi。

Security Manager（安全管理）

建议使用独立进程（separate process）运行。

部分特性在 SVM 的实现会有所差异

Class Initializers

类初始化操作可以在构建 Native Image 时进行，也可以在应用启动时进行。有点高深，此处不展开。

不再调用 finalize() 方法

由于 finalize() 方法从 Java 9 开始废弃，SVM 将不会调用该方法，建议使用弱引用或引用队列代替 finalize() 方法。

SVM 未实现 java.lang.Thread 中的废弃方法

在 java.lang.Thread 类中，SVM 没有实现已经被废弃的方法，例如 Thread.stop() 等。

Unsafe 相关

有点高深，此处不展开。

尝试构建 Spring Boot 项目的 Native Image

默认参数构建出 Fallback Image

有一个 Spring Boot Eureka Server 的 jar，构建 Native Image：

➜  libs $GRAALVM_HOME/bin/native-image -jar eureka-server-1.0-SNAPSHOT.jar eureka-server
Build on Server(pid: 29364, port: 34701)
[eureka-server:29364]    classlist:     107.58 ms,  5.12 GB
[eureka-server:29364]        (cap):     308.11 ms,  5.12 GB
[eureka-server:29364]        setup:     628.09 ms,  5.12 GB
[eureka-server:29364]     (clinit):     127.87 ms,  5.12 GB
[eureka-server:29364]     analysis:  13,088.76 ms,  5.12 GB
Warning: Aborting stand-alone image build due to unsupported features
Warning: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Build on Server(pid: 29364, port: 34701)
[eureka-server:29364]    classlist:      79.87 ms,  5.12 GB
[eureka-server:29364]        (cap):     277.76 ms,  5.12 GB
[eureka-server:29364]        setup:     556.38 ms,  5.12 GB
[eureka-server:29364]     (clinit):      78.21 ms,  5.12 GB
[eureka-server:29364]   (typeflow):   2,907.80 ms,  5.12 GB
[eureka-server:29364]    (objects):   3,545.23 ms,  5.12 GB
[eureka-server:29364]   (features):      70.02 ms,  5.12 GB
[eureka-server:29364]     analysis:   6,753.20 ms,  5.12 GB
[eureka-server:29364]     universe:     113.26 ms,  5.12 GB
[eureka-server:29364]      (parse):     310.65 ms,  5.12 GB
[eureka-server:29364]     (inline):     430.37 ms,  5.12 GB
[eureka-server:29364]    (compile):   3,658.23 ms,  5.17 GB
[eureka-server:29364]      compile:   4,703.36 ms,  5.17 GB
[eureka-server:29364]        image:     406.92 ms,  5.17 GB
[eureka-server:29364]        write:     150.86 ms,  5.17 GB
[eureka-server:29364]      [total]:  12,805.75 ms,  5.17 GB
Warning: Image 'eureka-server' is a fallback image that requires a JDK for execution (use --no-fallback to suppress fallback image generation and to print more detailed information why a fallback image was necessary).
➜  libs ls
eureka-server  eureka-server-1.0-SNAPSHOT.jar
➜  libs ./eureka-server .   ____          _            __ _ _/\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \\\/  ___)| |_)| | | | | || (_| |  ) ) ) )'  |____| .__|_| |_|_| |_\__, | / / / /=========|_|==============|___/=/_/_/_/:: Spring Boot ::        (v2.2.6.RELEASE)2020-06-06 13:55:03.608  INFO 25975 --- [           main] v.w.p.e.server.EurekaServerApplication   : No active profile set, falling back to default profiles: default
......
2020-06-06 13:55:06.926  INFO 25975 --- [           main] v.w.p.e.server.EurekaServerApplication   : Started EurekaServerApplication in 4.201 seconds (JVM running for 4.758)

虽然构建出来可以运行，但是警告信息中也提醒了，这是一个 Fallback Image，仍然依赖 JVM 运行。

指定不使用 Fallback Image

如果通过 --no-fallback 指定不使用 Fallback Image，则构建过程中会报错：

➜  libs $GRAALVM_HOME/bin/native-image -jar eureka-server-1.0-SNAPSHOT.jar eureka-server --no-fallback
Build on Server(pid: 29364, port: 34701)
[eureka-server:29364]    classlist:      84.36 ms,  5.18 GB
[eureka-server:29364]        (cap):     255.60 ms,  5.18 GB
[eureka-server:29364]        setup:     538.53 ms,  5.18 GB
[eureka-server:29364]     (clinit):     123.71 ms,  5.18 GB
[eureka-server:29364]   (typeflow):   5,010.03 ms,  5.18 GB
[eureka-server:29364]    (objects):   7,302.70 ms,  5.18 GB
[eureka-server:29364]   (features):     131.10 ms,  5.18 GB
[eureka-server:29364]     analysis:  12,819.24 ms,  5.18 GB
Error: com.oracle.svm.hosted.substitute.DeletedElementException: Unsupported field java.net.URL.handlers is reachable
To diagnose the issue, you can add the option --report-unsupported-elements-at-runtime. The unsupported element is then reported at run time when it is accessed the first time.
Detailed message:
Trace: at parsing java.net.URL.setURLStreamHandlerFactory(URL.java:1213)
Call path from entry point to java.net.URL.setURLStreamHandlerFactory(URLStreamHandlerFactory): at java.net.URL.setURLStreamHandlerFactory(URL.java:1205)at org.springframework.boot.loader.jar.JarFile.resetCachedUrlHandlers(JarFile.java:408)at org.springframework.boot.loader.jar.JarFile.registerUrlProtocolHandler(JarFile.java:398)at org.springframework.boot.loader.Launcher.launch(Launcher.java:49)at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52)at com.oracle.svm.core.JavaMainWrapper.runCore(JavaMainWrapper.java:149)at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:184)at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Error: Image build request failed with exit status 1

指定运行时才报告错误

通过 --report-unsupported-elements-at-runtime 指定运行期间才抛出异常，则可以编译出可执行程序，但执行会报错：

➜  libs $GRAALVM_HOME/bin/native-image -jar eureka-server-1.0-SNAPSHOT.jar eureka-server --no-fallback --report-unsupported-elements-at-runtime 
Build on Server(pid: 29364, port: 34701)
[eureka-server:29364]    classlist:      88.63 ms,  5.18 GB
[eureka-server:29364]        (cap):     263.34 ms,  5.18 GB
[eureka-server:29364]        setup:     533.79 ms,  5.18 GB
[eureka-server:29364]     (clinit):     165.56 ms,  5.18 GB
[eureka-server:29364]   (typeflow):   5,307.18 ms,  5.18 GB
[eureka-server:29364]    (objects):   7,254.71 ms,  5.18 GB
[eureka-server:29364]   (features):     121.96 ms,  5.18 GB
[eureka-server:29364]     analysis:  13,087.96 ms,  5.18 GB
[eureka-server:29364]     universe:     223.50 ms,  5.18 GB
[eureka-server:29364]      (parse):     418.09 ms,  5.18 GB
[eureka-server:29364]     (inline):     679.36 ms,  5.12 GB
[eureka-server:29364]    (compile):   6,067.78 ms,  5.19 GB
[eureka-server:29364]      compile:   7,730.92 ms,  5.19 GB
[eureka-server:29364]        image:     859.48 ms,  5.19 GB
[eureka-server:29364]        write:     175.21 ms,  5.19 GB
[eureka-server:29364]      [total]:  22,735.96 ms,  5.19 GB➜  libs ./eureka-server 
Exception in thread "main" java.lang.IllegalStateException: java.util.zip.ZipException: zip END header not foundat org.springframework.boot.loader.ExecutableArchiveLauncher.<init>(ExecutableArchiveLauncher.java:42)at org.springframework.boot.loader.JarLauncher.<init>(JarLauncher.java:36)at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52)
Caused by: java.util.zip.ZipException: zip END header not foundat java.util.zip.ZipFile$Source.zerror(ZipFile.java:1535)at java.util.zip.ZipFile$Source.findEND(ZipFile.java:1436)at java.util.zip.ZipFile$Source.initCEN(ZipFile.java:1443)at java.util.zip.ZipFile$Source.<init>(ZipFile.java:1274)at java.util.zip.ZipFile$Source.get(ZipFile.java:1237)at java.util.zip.ZipFile$CleanableResource.<init>(ZipFile.java:727)at java.util.zip.ZipFile$CleanableResource.get(ZipFile.java:55)at java.util.zip.ZipFile.<init>(ZipFile.java:247)at java.util.zip.ZipFile.<init>(ZipFile.java:177)at java.util.jar.JarFile.<init>(JarFile.java:348)at java.util.jar.JarFile.<init>(JarFile.java:319)at java.util.jar.JarFile.<init>(JarFile.java:285)at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:119)at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:114)at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:100)at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:91)at org.springframework.boot.loader.archive.JarFileArchive.<init>(JarFileArchive.java:61)at org.springframework.boot.loader.archive.JarFileArchive.<init>(JarFileArchive.java:57)at org.springframework.boot.loader.Launcher.createArchive(Launcher.java:127)at org.springframework.boot.loader.ExecutableArchiveLauncher.<init>(ExecutableArchiveLauncher.java:39)... 2 more

压缩类的异常，本人判断是 Native Image 没有考虑到 Spring Boot 这种 “Jar 中 Jar” 的结构 。

基于 class 文件和指定 classpath 构建 Native Image

/usr/local/graalvm-ee-java11-20.1.0/bin/native-image vip.wuweijie.project.eureka.server.EurekaServerApplication -cp /home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/antlr-2.7.7.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/antlr-runtime-3.4.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aopalliance-1.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/archaius-core-0.7.6.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aspectjweaver-1.9.5.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aws-java-sdk-autoscaling-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aws-java-sdk-core-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aws-java-sdk-ec2-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aws-java-sdk-route53-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/aws-java-sdk-sts-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/bcpkix-jdk15on-1.64.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/bcprov-jdk15on-1.64.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/checker-compat-qual-2.5.5.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/classmate-1.5.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-codec-1.13.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-collections-3.2.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-configuration-1.8.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-jxpath-1.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-lang-2.6.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/commons-math-2.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/error_prone_annotations-2.3.4.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/eureka-client-1.9.17.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/eureka-core-1.9.17.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/evictor-1.0.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/failureaccess-1.0.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/FastInfoset-1.2.16.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/freemarker-2.3.30.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/gson-2.8.6.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/guava-28.2-android.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/guice-4.1.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/HdrHistogram-2.1.11.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/hibernate-validator-6.0.18.Final.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/httpclient-4.5.12.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/httpcore-4.4.13.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/hystrix-core-1.5.18.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ion-java-1.0.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/istack-commons-runtime-3.0.8.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/j2objc-annotations-1.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-annotations-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-core-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-databind-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-dataformat-cbor-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-dataformat-xml-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-datatype-jdk8-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-datatype-jsr310-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-module-jaxb-annotations-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jackson-module-parameter-names-2.10.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jakarta.activation-api-1.2.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jakarta.annotation-api-1.3.5.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jakarta.validation-api-2.0.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jakarta.xml.bind-api-2.3.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/javax.inject-1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jaxb-runtime-2.3.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jboss-logging-3.4.1.Final.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jersey-apache-client4-1.19.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jersey-client-1.19.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jersey-core-1.19.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jersey-server-1.19.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jersey-servlet-1.19.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jettison-1.3.7.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jmespath-java-1.11.415.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/joda-time-2.10.5.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jsr305-3.0.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jsr311-api-1.1.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/jul-to-slf4j-1.7.30.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/LatencyUtils-2.0.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/log4j-api-2.12.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/log4j-to-slf4j-2.12.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/logback-classic-1.2.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/logback-core-1.2.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/micrometer-core-1.3.6.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/netflix-commons-util-0.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/netflix-eventbus-0.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/netflix-infix-0.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/netflix-statistics-0.1.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/reactive-streams-1.0.3.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/reactor-core-3.3.4.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/reactor-extra-3.3.3.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-core-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-eureka-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-httpclient-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-loadbalancer-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/ribbon-transport-2.3.0.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/rxjava-1.3.8.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/rxnetty-0.4.9.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/rxnetty-contexts-0.4.9.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/rxnetty-servo-0.4.9.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/servo-core-0.12.21.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/slf4j-api-1.7.30.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/snakeyaml-1.25.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-aop-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-beans-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-actuator-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-actuator-autoconfigure-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-autoconfigure-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-actuator-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-aop-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-cache-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-freemarker-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-json-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-logging-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-tomcat-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-validation-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-boot-starter-web-2.2.6.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-commons-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-context-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-loadbalancer-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-netflix-archaius-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-netflix-eureka-client-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-netflix-eureka-server-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-netflix-hystrix-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-netflix-ribbon-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-starter-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-starter-loadbalancer-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-starter-netflix-archaius-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-starter-netflix-eureka-server-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-cloud-starter-netflix-ribbon-2.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-context-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-context-support-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-core-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-expression-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-jcl-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-security-crypto-5.2.2.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-security-rsa-1.0.9.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-web-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/spring-webmvc-5.2.5.RELEASE.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/stax2-api-4.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/stax-api-1.0.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/stax-ex-1.8.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/stringtemplate-3.2.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/tomcat-embed-core-9.0.33.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/tomcat-embed-el-9.0.33.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/tomcat-embed-websocket-9.0.33.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/txw2-2.3.2.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/woodstox-core-6.1.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/xmlpull-1.1.3.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/xpp3_min-1.1.4c.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/libs/deps/xstream-1.4.11.1.jar:/home/sia/IdeaProjects/hello-world/eureka-server/build/classes/java/main --no-fallback --report-unsupported-elements-at-runtime
Shutdown Server(pid: 29364, port: 34701)
Build on Server(pid: 11904, port: 41579)*
[vip.wuweijie.project.eureka.server.eurekaserverapplication:11904]    classlist:  11,353.59 ms,  2.69 GB
[vip.wuweijie.project.eureka.server.eurekaserverapplication:11904]        (cap):     571.36 ms,  2.69 GB
[vip.wuweijie.project.eureka.server.eurekaserverapplication:11904]        setup:   2,316.11 ms,  2.69 GB
[vip.wuweijie.project.eureka.server.eurekaserverapplication:11904]     analysis:   7,777.10 ms,  2.70 GB
Error: Classes that should be initialized at run time got initialized during image building:org.springframework.util.unit.DataSize was unintentionally initialized at build time. To see why org.springframework.util.unit.DataSize got initialized use -H:+TraceClassInitializationError: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Error: Image build request failed with exit status 1
make: *** [build-native] Error 1
/home/sia/IdeaProjects/hello-world/eureka-server/Makefile:14: recipe for target 'build-native' failed

这就触及本人的知识盲区了，本文不再深入研究。

添加各项追踪参数的完整日志请见：https://paste.ubuntu.com/p/HZzyhR7bSQ/

Quarkus - Supersonic Subatomic Java

称为 “超声波 Java” 的 Quarkus 有什么特性？

CONTAINER FIRST（容器优先）

Quarkus 完全支持 Graal / SubstrateVM：能够直接构建 Native Image 可执行程序
Quarkus 会在构建时期尽量将不需要用到的类等可精简项排除掉，以实现更短的启动时间和更少的内存占用
Quarkus 尽量避免使用反射（Reflection），减少启动时间和内存占用
Quarkus 会尽量将一些启动工作放在 Native Image 构建期间完成，以减少启动时间

官方提供的 Quarkus原生应用、Quarkus JVM、传统云原生技术栈的内存占用、启动时间对比图：

UNIFIES IMPERATIVE AND REACTIVE（统一命令式和响应式编程）

无论是使用命令式还是响应式编程，都有相近的代码风格

命令式：

@Inject
SayService say;@GET
@Produces(MediaType.TEXT_PLAIN)
public String hello() {return say.hello();
}

响应式：

@Inject @Channel("kafka")
Publisher<String> reactiveSay;@GET
@Produces(MediaType.SERVER_SENT_EVENTS)
public Publisher<String> stream() {return reactiveSay;
}

DEVELOPER JOY（开发者友好）

Quarkus 统一了各种不同的技术框架的配置
Quarkus 在开发模式下可以实现保存代码即运行，而且开箱即用，无需额外配置
Quarkus 支持各类构建工具，Maven, Gradle 或者 IDE
Quarkus 将尽量统一开发的方式与风格

BEST OF BREED LIBRARIES AND STANDARDS（基于最好的库和标准）

Quarkus 不会让用户花费大量时间学习新技术，其编程模型建立在各种已有的标准之上，例如：

JPA
Spring
JTA
Vert.x
CDI
JAX-RS
Apache Camel
…

说这么多，不如试试

初始化 Quarkus 项目

Quarkus 提供了一个类似于 Spring Initializr 的项目初始化方式：https://code.quarkus.io/

任选一种初始化方式：

在 https://code.quarkus.io/ 完成初始化并下载项目
在 IntelliJ IDEA 创建 Quarkus 项目（推荐，封装了 code.quarkus.io）

以下操作基于 IntelliJ IDEA。

可选构建工具：

Maven
Gradle (Preview)

选择依赖：

RESTEasy JAX-RS 默认选择
数据库相关
Spring 相关（Preview 阶段，选来体验一下）

项目初始化后且依赖下载完成后，可以使用 ./mvnw compile quarkus:dev 运行项目，或者通过 GUI：

Quarkus 启动：

在浏览器打开 http://localhost:8080/

项目初始化完成。

数据库准备

create table t_order
(id bigserial not nullconstraint t_order_pkprimary key,order_time timestamp default CURRENT_TIMESTAMP not null,person_name varchar default ''::character varying not null,order_type varchar default 'None'::character varying not null,remark varchar
);alter table t_order owner to postgres;INSERT INTO public.t_order (id, order_time, person_name, order_type, remark) VALUES (1, '2020-06-06 16:31:16.000000', '烫烫烫', 'None', null);
INSERT INTO public.t_order (id, order_time, person_name, order_type, remark) VALUES (2, '2020-06-06 16:31:51.000000', '锟斤拷', 'Dinner', 'Double');

基于 Spring 体系的 CRUD 代码

Quarkus 提供了 Spring 的兼容。

Order.java 节选，忽略 getter / setter：

package vip.wuweijie.hello.quarkus.entity;import javax.persistence.*;
import java.io.Serializable;
import java.sql.Timestamp;/*** @author wuweijie*/
@Entity
public class Order implements Serializable {@Idprivate Long id;@Column(insertable = false)private Timestamp orderTime;private String personName;private String orderType;private String remark;
}

OrderRepository.java：

package vip.wuweijie.hello.quarkus.repository;import org.springframework.data.jpa.repository.JpaRepository;
import vip.wuweijie.hello.quarkus.entity.Order;/*** @author wuweijie*/
public interface OrderRepository extends JpaRepository<Order, Long> {
}

OrderResource.java

package vip.wuweijie.hello.quarkus;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import vip.wuweijie.hello.quarkus.entity.Order;
import vip.wuweijie.hello.quarkus.repository.OrderRepository;import java.util.List;/*** @author wuweijie*/
@RestController
@RequestMapping("/order")
public class OrderResource {@Autowiredprivate OrderRepository orderRepository;@GetMappingpublic List<Order> getOrders() {return orderRepository.findAll();}@PostMappingpublic Order addOrder(@RequestBody Order order) {return orderRepository.saveAndFlush(order);}
}

在 Dev 模式运行验证

请求：

GET http://localhost:8080/order
###POST http://localhost:8080/order
Content-Type: application/json{"orderTime": 1591432276000,"personName": "POST","orderType": "nil","remark": "From Post"
}

先执行一次查询：

GET http://localhost:8080/orderHTTP/1.1 200 OK
Content-Length: 287
Content-Type: application/json[{"id": 1,"orderTime": 1591432276000,"personName": "烫烫烫","orderType": "None","remark": null},{"id": 2,"orderTime": 1591432311000,"personName": "锟斤拷","orderType": "Dinner","remark": "Double"}
]

执行一次插入，返回数据：

{"id":3,"orderTime":1591432276000,"personName":"POST","orderType":"nil","remark":"From Post"}

再次查询数据：

GET http://localhost:8080/orderHTTP/1.1 200 OK
Content-Length: 287
Content-Type: application/json[{"id": 1,"orderTime": 1591432276000,"personName": "烫烫烫","orderType": "None","remark": null},{"id": 2,"orderTime": 1591432311000,"personName": "锟斤拷","orderType": "Dinner","remark": "Double"},{"id": 3,"orderTime": 1591434989319,"personName": "POST","orderType": "nil","remark": "From Post"}
]

dev 模式下支持 Hot Reload

如果检测到代码文件变化，则会重新加载代码：

2020-06-06 17:16:28,560 INFO  [io.qua.dep.dev] (vert.x-worker-thread-1) Changed source files detected, recompiling [/home/sia/IdeaProjects/hello-quarkus/src/main/java/vip/wuweijie/hello/quarkus/entity/Order.java]
2020-06-06 17:16:28,950 INFO  [io.quarkus] (Quarkus Main Thread) hello-quarkus stopped in 0.030s
__  ____  __  _____   ___  __ ____  ______ --/ __ \/ / / / _ | / _ \/ //_/ / / / __/ -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \   
--\___\_\____/_/ |_/_/|_/_/|_|\____/___/   
2020-06-06 17:16:29,130 INFO  [io.qua.arc.pro.BeanProcessor] (build-26) Found unrecommended usage of private members (use package-private instead) in application beans:- @Inject field vip.wuweijie.hello.quarkus.OrderResource#orderRepository
2020-06-06 17:16:29,220 INFO  [io.agr.pool] (Quarkus Main Thread) Datasource '<default>': Initial size smaller than min. Connections will be created when necessary
2020-06-06 17:16:29,258 INFO  [io.quarkus] (Quarkus Main Thread) hello-quarkus 1.0-SNAPSHOT on JVM (powered by Quarkus 1.5.0.Final) started in 0.301s. Listening on: http://0.0.0.0:8080
2020-06-06 17:16:29,259 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2020-06-06 17:16:29,259 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, jdbc-postgresql, mutiny, narayana-jta, resteasy, resteasy-jackson, spring-boot-properties, spring-data-jpa, spring-di, spring-web]
2020-06-06 17:16:29,259 INFO  [io.qua.dep.dev] (vert.x-worker-thread-1) Hot replace total time: 0.700s

构建 Native Image

本示例 建议可用内存不小于 8GB ，依赖越多，构建过程所需内存越大。

执行命令

./mvnw package -Pnative

执行日志：

➜  hello-quarkus git:(master) ✗ ./mvnw package -Pnative
[INFO] Scanning for projects...
[INFO] 
[INFO] --------------< vip.wuweijie.hello.quarkus:hello-quarkus >--------------
[INFO] Building hello-quarkus 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ hello-quarkus ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 2 resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ hello-quarkus ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 4 source files to /home/sia/IdeaProjects/hello-quarkus/target/classes
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ hello-quarkus ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/sia/IdeaProjects/hello-quarkus/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ hello-quarkus ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to /home/sia/IdeaProjects/hello-quarkus/target/test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ hello-quarkus ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running vip.wuweijie.hello.quarkus.ExampleResourceTest
2020-06-06 17:28:56,229 INFO  [io.qua.arc.pro.BeanProcessor] (build-4) Found unrecommended usage of private members (use package-private instead) in application beans:- @Inject field vip.wuweijie.hello.quarkus.OrderResource#orderRepository
2020-06-06 17:28:57,057 INFO  [io.agr.pool] (main) Datasource '<default>': Initial size smaller than min. Connections will be created when necessary
2020-06-06 17:28:57,446 INFO  [io.quarkus] (main) Quarkus 1.5.0.Final on JVM started in 2.301s. Listening on: http://0.0.0.0:8081
2020-06-06 17:28:57,447 INFO  [io.quarkus] (main) Profile test activated. 
2020-06-06 17:28:57,447 INFO  [io.quarkus] (main) Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, jdbc-postgresql, mutiny, narayana-jta, resteasy, resteasy-jackson, spring-boot-properties, spring-data-jpa, spring-di, spring-web]
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 4.775 s - in vip.wuweijie.hello.quarkus.ExampleResourceTest
2020-06-06 17:28:58,615 INFO  [io.quarkus] (main) Quarkus stopped in 0.034s
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ hello-quarkus ---
[INFO] Building jar: /home/sia/IdeaProjects/hello-quarkus/target/hello-quarkus-1.0-SNAPSHOT.jar
[INFO] 
[INFO] --- quarkus-maven-plugin:1.5.0.Final:build (default) @ hello-quarkus ---
[INFO] [org.jboss.threads] JBoss Threads version 3.1.1.Final
[INFO] [org.hibernate.Version] HHH000412: Hibernate ORM core version 5.4.16.Final
[INFO] [io.quarkus.arc.processor.BeanProcessor] Found unrecommended usage of private members (use package-private instead) in application beans:- @Inject field vip.wuweijie.hello.quarkus.OrderResource#orderRepository
[INFO] [io.quarkus.deployment.pkg.steps.JarResultBuildStep] Building native image source jar: /home/sia/IdeaProjects/hello-quarkus/target/hello-quarkus-1.0-SNAPSHOT-native-image-source-jar/hello-quarkus-1.0-SNAPSHOT-runner.jar
[INFO] [io.quarkus.deployment.pkg.steps.NativeImageBuildStep] Building native image from /home/sia/IdeaProjects/hello-quarkus/target/hello-quarkus-1.0-SNAPSHOT-native-image-source-jar/hello-quarkus-1.0-SNAPSHOT-runner.jar
[INFO] [io.quarkus.deployment.pkg.steps.NativeImageBuildStep] Running Quarkus native-image plugin on GraalVM Version 20.1.0 (Java Version 11.0.7)
[INFO] [io.quarkus.deployment.pkg.steps.NativeImageBuildStep] /usr/local/graalvm-ee-java11-20.1.0/bin/native-image -J-Dsun.nio.ch.maxUpdateArraySize=100 -J-Djava.util.logging.manager=org.jboss.logmanager.LogManager -J-DCoordinatorEnvironmentBean.transactionStatusManagerEnable=false -J-Dvertx.logger-delegate-factory-class-name=io.quarkus.vertx.core.runtime.VertxLogDelegateFactory -J-Dvertx.disableDnsResolver=true -J-Dio.netty.leakDetection.level=DISABLED -J-Dio.netty.allocator.maxOrder=1 -J-Duser.language=en -J-Dfile.encoding=UTF-8 --initialize-at-build-time= -H:InitialCollectionPolicy=com.oracle.svm.core.genscavenge.CollectionPolicy$BySpaceAndTime -H:+JNI -jar hello-quarkus-1.0-SNAPSHOT-runner.jar -H:FallbackThreshold=0 -H:+ReportExceptionStackTraces -H:-AddAllCharsets -H:-IncludeAllTimeZones -H:EnableURLProtocols=http,https --enable-all-security-services -H:NativeLinkerOption=-no-pie --no-server -H:-UseServiceLoaderFeature -H:+StackTrace hello-quarkus-1.0-SNAPSHOT-runner
-H:IncludeAllTimeZones and -H:IncludeTimeZones are now deprecated. Native-image includes all timezonesby default.
[hello-quarkus-1.0-SNAPSHOT-runner:9103]    classlist:   6,932.73 ms,  1.19 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]        (cap):     541.19 ms,  1.68 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]        setup:   2,467.68 ms,  1.68 GB
17:29:11,362 INFO  [org.hib.Version] HHH000412: Hibernate ORM core version 5.4.16.Final
17:29:11,367 INFO  [org.hib.ann.com.Version] HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
17:29:11,384 INFO  [org.hib.dia.Dialect] HHH000400: Using dialect: io.quarkus.hibernate.orm.runtime.dialect.QuarkusPostgreSQL10Dialect
17:29:23,231 INFO  [org.jbo.threads] JBoss Threads version 3.1.1.Final
WARNING GR-10238: VarHandle for static field is currently not fully supported. Static field private static volatile java.lang.System$Logger jdk.internal.event.EventHelper.securityLogger is not properly marked for Unsafe access!
[hello-quarkus-1.0-SNAPSHOT-runner:9103]     (clinit):     873.00 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]   (typeflow):  21,272.04 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]    (objects):  26,923.87 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]   (features):   1,099.55 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]     analysis:  53,824.27 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]     universe:   1,649.18 ms,  5.41 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]      (parse):   4,248.05 ms,  5.59 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]     (inline):   2,953.33 ms,  5.79 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]    (compile):  61,356.01 ms,  7.23 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]      compile:  72,475.76 ms,  7.23 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]        image:   5,032.36 ms,  7.23 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]        write:     995.36 ms,  7.23 GB
[hello-quarkus-1.0-SNAPSHOT-runner:9103]      [total]: 143,635.77 ms,  7.23 GB
[INFO] [io.quarkus.deployment.QuarkusAugmentor] Quarkus augmentation completed in 145589ms
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  02:34 min
[INFO] Finished at: 2020-06-06T17:31:25+08:00
[INFO] ------------------------------------------------------------------------

构建完成后，target 目录下多了一个可执行文件。

执行后，可以看到应用的启动时间只需要 0.043s，基于 JVM 启动需要 1.730s。

以上就是 Quarkus 的体验过程。

参考资料

GraalVM 相关：

https://docs.oracle.com/en/graalvm/enterprise/20/guide/index.html
https://github.com/oracle/graal/blob/master/substratevm/LIMITATIONS.md
https://github.com/oracle/graal/blob/master/substratevm/CONFIGURE.md
https://github.com/oracle/graal/blob/master/substratevm/REFLECTION.md

Quarkus 相关：

https://quarkus.io/assets/images/quarkus_metrics_graphic_bootmem_wide.png
https://quarkus.io/
https://quarkus.io/vision/container-first
https://quarkus.io/vision/standards
https://quarkus.io/vision/developer-joy
https://quarkus.io/vision/continuum
https://quarkus.io/guides/building-native-image

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