簡介

在之前spring boot3文章中我們介紹了，spring boot3的一個重要特性就是支持把spring boot3的應用編譯成為GraalVM的Native Image。

今天我們用具體的例子來給大家演示一下如何正確的將spring boot3的應用編譯成為native image。

安裝GraalVM

如果要把spring boot3的app編譯成為native應用，需要GraalVM的支持。

什么是GraalVM呢？

從名字就可以看出來GraalVM是一個虛擬機，它的主要目標就是提升java應用程序的性能，并且消耗更少的資源。

它在java HotSpot JVM的基礎上添加了JIT編譯器和AOT來實現將應用編譯成為本地可執(zhí)行文件。除了java之外，GraalVM還支持JavaScript、Ruby、Python等多種編程語言。

所以，為什么要用GraalVM呢？一個字：快。

安裝GraalVM也比較簡單，我們進入它的官方下載頁面下載對應的版本即可：https://www.oracle.com/downloads/graalvm-downloads.html。

GraalVM跟JDK一樣也有兩個版本，社區(qū)版和企業(yè)版本，大家可以根據需要自行選擇。

要注意的是spring boot3需要GraalVM 22.3以上的版本支持，大家可不要下載錯了。

下載完成之后，我們可以像正常安裝JDK一樣來安裝GraalVM,這里以mac為例，假如我們安裝的目錄是/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0，那么我們需要配置對應的JAVA_HOME和PATH環(huán)境變量如下：

 export PATH=/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0/Contents/Home/bin:$PATH

 export JAVA_HOME=/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0/Contents/Home
 export PATH=/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0/Contents/Home/bin:$PATH

 export JAVA_HOME=/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0/Contents/Home

PATH中有一個非常重要的命令叫做gu，如果不添加PATH，那么在使用中就可能遇到下面的異常：

'gu' tool wasn't found. This probably means that JDK at isn't a GraalVM distribution.

安裝完畢之后可以通過下面的命令來進行驗證：

java -version
java version "17.0.5" 2022-10-18 LTS
Java(TM) SE Runtime Environment GraalVM EE 22.3.0 (build 17.0.5+9-LTS-jvmci-22.3-b07)
Java HotSpot(TM) 64-Bit Server VM GraalVM EE 22.3.0 (build 17.0.5+9-LTS-jvmci-22.3-b07, mixed mode, sharing)

如果是在mac環(huán)境下，還需要執(zhí)行下面的命令來解除對graalvm的隔離限制：

 sudo xattr -r -d com.apple.quarantine /path/to/graalvm

否則在使用中就會遇到下面的問題：

添加Native Image支持

我們安裝GraalVM的目的就是使用它的native Image特性。native image是一個單獨的jar包，我們可以執(zhí)行下面的命令來進行安裝：

gu install native-image

其中gu就是/Library/Java/JavaVirtualMachines/graalvm-ee-java17-22.3.0/Contents/Home/bin中的命令。

下載的過程中還需要輸入一個有效的郵件，并進行郵箱校驗。然后一路ENTER就可以了。

當然，你還可以把Oracle GraalVM Enterprise Edition Native Image下載到本地，然后使用gu install -L來進行本地安裝。

好了，到目前為止，一切準備妥當，我們接下來看看如何把spring boot3的應用打包成為native image吧。

構建spring boot3應用

這里我們使用的是maven，所以需要添加下面的spring boot3的依賴：

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.1</version>
        <relativePath/> 
    </parent>

因為要構建native image，所以我們還需要用到下面的一個native-maven-plugin插件：

<plugin>
                <groupId>org.graalvm.buildtools</groupId>
                <artifactId>native-maven-plugin</artifactId>
            </plugin>

這里我們只創(chuàng)建了一個非常簡單的main方法：

@SpringBootApplication
public class NativeImageApplication {

    public static void main(String[] args) {
        SpringApplication.run(NativeImageApplication.class, args);
    }
}

然后，我們嘗試運行 mvn native:build來構建spring boot3應用程序。

記得在build之前一定先要編譯好項目。

很可惜，你會發(fā)現下面的異常：

[INFO] --- native-maven-plugin:0.9.19:build (default-cli) @ native-image --- [WARNING] 'native:build' goal is deprecated. Use 'native:compile-no-fork' instead. [INFO] Found GraalVM installation from JAVA_HOME variable. ... Error: Please specify class (or <module>/<mainclass>) containing the main entry point method. (see --help)

從上面的異常我們發(fā)現了兩個問題，第一個問題是一個警告，它推薦我們使用native:compile-no-fork。

第二個問題是說找不到mainclass,根據異常信息，我們在pom的plugin中添加下面的配置信息，如下所示：

<plugin>
                <groupId>org.graalvm.buildtools</groupId>
                <artifactId>native-maven-plugin</artifactId>
                <configuration>
                    <!-- imageName用于設置生成的二進制文件名稱 -->
                    <imageName>${project.artifactId}</imageName>
                    <!-- mainClass用于指定main方法類路徑 -->
                    <mainClass>com.flydean.nativeimage.NativeImageApplication</mainClass>
                    <buildArgs>
                        --no-fallback
                    </buildArgs>
                </configuration>
                <executions>
                    <execution>
                        <id>build-native</id>
                        <goals>
                            <goal>compile-no-fork</goal>
                        </goals>
                        <phase>package</phase>
                    </execution>
                </executions>
            </plugin>

然后重新運行mvn native:compile-no-fork：

GraalVM Native Image: Generating 'native-image' (executable)... ======================================================================================================================== [1/7] Initializing... (4.3s @ 0.25GB) Version info: 'GraalVM 22.3.0 Java 17 EE' Java version info: '17.0.5+9-LTS-jvmci-22.3-b07' C compiler: cc (apple, arm64, 14.0.0) Garbage collector: Serial GC 1 user-specific feature(s) - org.springframework.aot.nativex.feature.PreComputeFieldFeature Field org.apache.commons.logging.LogAdapter#log4jSpiPresent set to true at build time Field org.apache.commons.logging.LogAdapter#log4jSlf4jProviderPresent set to true at build time Field org.apache.commons.logging.LogAdapter#slf4jSpiPresent set to true at build time Field org.apache.commons.logging.LogAdapter#slf4jApiPresent set to true at build time Field org.springframework.core.NativeDetector#imageCode set to true at build time Field org.springframework.core.KotlinDetector#kotlinPresent set to false at build time Field org.springframework.core.KotlinDetector#kotlinReflectPresent set to false at build time Field org.springframework.format.support.DefaultFormattingConversionService#jsr354Present set to false at build time Field org.springframework.cglib.core.AbstractClassGenerator#imageCode set to true at build time [2/7] Performing analysis... [**********] (24.8s @ 4.57GB) 10,266 (89.50%) of 11,470 classes reachable 16,675 (63.53%) of 26,248 fields reachable 53,776 (60.71%) of 88,575 methods reachable 469 classes, 140 fields, and 2,281 methods registered for reflection 63 classes, 69 fields, and 55 methods registered for JNI access 5 native libraries: -framework CoreServices, -framework Foundation, dl, pthread, z [3/7] Building universe... (5.0s @ 2.72GB) [4/7] Parsing methods... [**] (4.4s @ 2.42GB) [5/7] Inlining methods... [***] (1.3s @ 3.87GB) [6/7] Compiling methods... [********] (70.0s @ 1.04GB) [7/7] Creating image... (4.7s @ 3.35GB) 30.27MB (58.75%) for code area: 30,771 compilation units 20.50MB (39.79%) for image heap: 305,579 objects and 93 resources 769.52KB ( 1.46%) for other data 51.52MB in total ------------------------------------------------------------------------------------------------------------------------ Top 10 packages in code area: Top 10 object types in image heap: 2.02MB com.oracle.svm.core.code 5.79MB byte[] for code metadata 1.77MB sun.security.ssl 2.31MB byte[] for java.lang.String 1.29MB java.util 2.09MB byte[] for general heap data 929.52KB java.lang.invoke 2.07MB java.lang.String 925.96KB com.sun.crypto.provider 1.76MB java.lang.Class 802.99KB java.lang 671.09KB byte[] for embedded resources 633.35KB sun.nio.ch 567.26KB byte[] for reflection metadata 625.89KB java.util.concurrent 481.22KB com.oracle.svm.core.hub.DynamicHubCompanion 601.86KB org.apache.tomcat.util.net 450.06KB java.util.HashMap$Node 594.48KB sun.security.x509 401.78KB java.util.concurrent.ConcurrentHashMap$Node 20.02MB for 397 more packages 3.40MB for 2297 more object types ------------------------------------------------------------------------------------------------------------------------ 9.5s (7.9% of total time) in 50 GCs | Peak RSS: 3.75GB | CPU load: 4.39 ------------------------------------------------------------------------------------------------------------------------ Produced artifacts: /Users/learn-springboot3/learn-springboot3/native-image/target/native-image (executable) /Users/learn-springboot3/learn-springboot3/native-image/target/native-image.build_artifacts.txt (txt) ======================================================================================================================== Finished generating 'native-image' in 2m 0s. [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 02:01 min [INFO] Finished at: 2023-01-05T20:43:39+08:00 [INFO] ------------------------------------------------------------------------

經過漫長的等待，我們終于build完成了。

因為我們的artifactId叫做native-image,所以最終在target目錄下面生成了一個叫做native-image的可執(zhí)行文件：

. ├── classes │   ├── application.properties │   └── com │   └── flydean │   └── nativeimage │   └── NativeImageApplication.class ├── generated-sources │   └── annotations ├── generated-test-sources │   └── test-annotations ├── maven-archiver │   └── pom.properties ├── maven-status │   └── maven-compiler-plugin │   ├── compile │   │   └── default-compile │   │   ├── createdFiles.lst │   │   └── inputFiles.lst │   └── testCompile │   └── default-testCompile │   ├── createdFiles.lst │   └── inputFiles.lst ├── native-image ├── native-image-0.0.1-SNAPSHOT.jar ├── native-image-0.0.1-SNAPSHOT.jar.original ├── native-image.build_artifacts.txt ├── surefire-reports │   ├── TEST-com.flydean.nativeimage.NativeImageApplicationTests.xml │   └── com.flydean.nativeimage.NativeImageApplicationTests.txt └── test-classes └── com └── flydean └── nativeimage └── NativeImageApplicationTests.class 20 directories, 14 files

如果你這時候運行target/native-image,那么很可能得到下面的異常：

[main] DEBUG org.springframework.context.aot.AotApplicationContextInitializer - Initializing ApplicationContext with AOT [main] ERROR org.springframework.boot.SpringApplication - Application run failed java.lang.IllegalArgumentException: Could not find class [com.flydean.nativeimage.NativeImageApplication__ApplicationContextInitializer] at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:333)

這是因為我們缺少一些spring boot的AOT元文件信息，正確的做法是使用下面的命令：

mvn clean package -Pnative

它實際上執(zhí)行的是下面的幾個命令：

mvn spring-boot:process-aot
mvn spring-boot:process-test-aot
mvn spring-boot:build-image

最終我們得到編譯好的native-image信息，運行得到下面的結果：

2023-01-05T17:07:11.692+08:00 INFO 69299 --- [ main] c.f.nativeimage.NativeImageApplication : Starting AOT-processed NativeImageApplication using Java 17.0.5 with PID 69299 (/Users/wayne/data/git/ddean2009/learn-springboot3/learn-springboot3/native-image/target/native-image started by wayne in /Users/wayne/data/git/ddean2009/learn-springboot3/learn-springboot3/native-image) 2023-01-05T17:07:11.693+08:00 INFO 69299 --- [ main] c.f.nativeimage.NativeImageApplication : No active profile set, falling back to 1 default profile: "default" 2023-01-05T17:07:11.709+08:00 INFO 69299 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) 2023-01-05T17:07:11.710+08:00 INFO 69299 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2023-01-05T17:07:11.710+08:00 INFO 69299 --- [ main] o.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.1.4] 2023-01-05T17:07:11.717+08:00 INFO 69299 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2023-01-05T17:07:11.717+08:00 INFO 69299 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 24 ms 2023-01-05T17:07:11.729+08:00 INFO 69299 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path '' 2023-01-05T17:07:11.729+08:00 INFO 69299 --- [ main] c.f.nativeimage.NativeImageApplication : Started NativeImageApplication in 0.053 seconds (process running for 0.072)

總結

從運行情況來看，native-image的啟動速度非常快，應該可以提升不少的性能。

感興趣的小伙伴趕緊用起來吧。

本文的例子https://github.com/ddean2009/learn-springboot3

到此這篇關于在spring boot3中使用native image的文章就介紹到這了,更多相關spring boot3使用native image內容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關文章希望大家以后多多支持腳本之家！

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