Prerequisites
- GraalVM is installed and
<GraalVM>/bindirectory is in the$PATH - Native Image is installed using the command
gu install native-image - Clone the graalvm-playground repository
Run in the VM
For convenience first run the example in the local JVM:
$ cd graalvm-playground/spring-web $./gradlew clean bootJar && \ time java -jar build/libs/spring-web-0.0.1-SNAPSHOT.jar BUILD SUCCESSFUL in 1s 4 actionable tasks: 4 executed . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.1.5.RELEASE) 2019-05-23 23:19:27.344 INFO 27401 --- [ main] me.dilek.graalvm.demo.DemoApplication : Starting DemoApplication on l380 with PID 27401 (/home/XXX/graalvm-playground/spring-web/build/libs/spring-web-0.0.1-SNAPSHOT.jar started by XXX in /home/XXX/graalvm-playground/spring-web) 2019-05-23 23:19:27.347 INFO 27401 --- [ main] me.dilek.graalvm.demo.DemoApplication : No active profile set, falling back to default profiles: default 2019-05-23 23:19:28.456 INFO 27401 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8081 (http) 2019-05-23 23:19:28.493 INFO 27401 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2019-05-23 23:19:28.493 INFO 27401 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.19] 2019-05-23 23:19:28.592 INFO 27401 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2019-05-23 23:19:28.593 INFO 27401 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1197 ms 2019-05-23 23:19:28.925 INFO 27401 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 2019-05-23 23:19:29.169 INFO 27401 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8081 (http) with context path '' 2019-05-23 23:19:29.171 INFO 27401 --- [ main] me.dilek.graalvm.demo.DemoApplication : Started DemoApplication in 2.194 seconds (JVM running for 2.633)
Build Native Image
Make sure that you have the right JVM version (Currently most recent supported version is JDK8-u212):
$ javac -version javac 1.8.0_212Try to build the native image
$ ./gradlew clean bootJar && \ native-image -jar build/libs/spring-web-0.0.1-SNAPSHOT.jar BUILD SUCCESSFUL in 0s 4 actionable tasks: 4 executed Build on Server(pid: 4674, port: 34081) [spring-web-0.0.1-SNAPSHOT:4674] classlist: 265.01 ms [spring-web-0.0.1-SNAPSHOT:4674] (cap): 919.46 ms [spring-web-0.0.1-SNAPSHOT:4674] setup: 1,221.87 ms [spring-web-0.0.1-SNAPSHOT:4674] analysis: 4,072.66 ms Warning: Aborting stand-alone image build. 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:1118) Call path from entry point to java.net.URL.setURLStreamHandlerFactory(URLStreamHandlerFactory): at java.net.URL.setURLStreamHandlerFactory(URL.java:1110) at org.springframework.boot.loader.jar.JarFile.resetCachedUrlHandlers(JarFile.java:401) at org.springframework.boot.loader.jar.JarFile.registerUrlProtocolHandler(JarFile.java:391) at org.springframework.boot.loader.Launcher.launch(Launcher.java:48) at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51) at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:153) at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0) Warning: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception Build on Server(pid: 4674, port: 34081) [spring-web-0.0.1-SNAPSHOT:4674] classlist: 114.69 ms [spring-web-0.0.1-SNAPSHOT:4674] (cap): 642.22 ms [spring-web-0.0.1-SNAPSHOT:4674] setup: 896.36 ms [spring-web-0.0.1-SNAPSHOT:4674] (typeflow): 1,503.32 ms [spring-web-0.0.1-SNAPSHOT:4674] (objects): 705.94 ms [spring-web-0.0.1-SNAPSHOT:4674] (features): 98.03 ms [spring-web-0.0.1-SNAPSHOT:4674] analysis: 2,358.07 ms [spring-web-0.0.1-SNAPSHOT:4674] (clinit): 64.41 ms [spring-web-0.0.1-SNAPSHOT:4674] universe: 202.79 ms [spring-web-0.0.1-SNAPSHOT:4674] (parse): 205.68 ms [spring-web-0.0.1-SNAPSHOT:4674] (inline): 586.94 ms [spring-web-0.0.1-SNAPSHOT:4674] (compile): 1,422.75 ms [spring-web-0.0.1-SNAPSHOT:4674] compile: 2,394.41 ms [spring-web-0.0.1-SNAPSHOT:4674] image: 245.09 ms [spring-web-0.0.1-SNAPSHOT:4674] write: 56.23 ms [spring-web-0.0.1-SNAPSHOT:4674] [total]: 6,324.13 ms Warning: Image 'spring-web-0.0.1-SNAPSHOT' is a fallback image that requires a JDK for execution (use --no-fallback to suppress fallback image generation).Check the resulting image:
$ ls -ahl ... -rwxr-xr-x 1 XXX XXX 2,6M Mai 23 23:22 spring-web-0.0.1-SNAPSHOT ...The resulting image requires a Java for execution!
Run the native image
$ ./spring-web-0.0.1-SNAPSHOT& ps -ef | grep java [1] 28883 XXX 28883 5089 0 23:31 pts/1 00:00:00 /home/XXX/tools/graalvm-ce-19.0.0/jre/bin/java -Dorg.graalvm.nativeimage.kind=fallback-executable -cp /home/XXX/mutfak/graalvm-playground/spring-web/build/libs/spring-web-0.0.1-SNAPSHOT.jar org.springframework.boot.loader.JarLauncher
Conclusion
The resulting image is not a real native image and needs a JRE to run. This is already indicated ruting native image build phase with the message Warning: Aborting stand-alone image build. com.oracle.svm.hosted.substitute.DeletedElementException: Unsupported field java.net.URL.handlers is reachable.
The reason is, current version of Spring 5.1 does not support GraalVM native images but the upcoming versions with 5.2 and 5.3 will mainly focus on supporting native images as mentioned here and here