序
本文主要研究怎么在docker的java9镜像上运行springboot2并精简jdk.
maven
org.springframework.boot spring-boot-starter-parent 2.0.0.RC2 UTF-8 UTF-8 9 com.example.demo.DemoApplication
注意springboot得2版本才能支持java9，另外这个java.version设置为9 这里maven用的版本是3.3.3
mvn package
mvn clean package -Dmaven.test.skip=true//......WARNING: An illegal reflective access operation has occurredWARNING: Illegal reflective access by lombok.javac.apt.LombokProcessor to field com.sun.tools.javac.processing.JavacProcessingEnvironment.discoveredProcsWARNING: Please consider reporting this to the maintainers of lombok.javac.apt.LombokProcessorWARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operationsWARNING: All illegal access operations will be denied in a future release
可以看到这里可以编译成功，但是有WARNING
docker构建
Dockerfile
FROM dekstroza/openjdk9-alpine as packager# First stage: JDK 9 with modules required for Spring BootRUN /opt/jdk-9/bin/jlink \ --module-path /opt/jdk-9/jmods \ --verbose \ --add-modules java.base,java.logging,java.xml,jdk.unsupported,java.sql,java.desktop,java.management,java.naming,java.instrument \ --compress 2 \ --no-header-files \ --output /opt/jdk-9-minimal# Second stage, add only our custom jdk9 distro and our appFROM alpine:3.6COPY --from=packager /opt/jdk-9-minimal /opt/jdk-9-minimalENV JAVA_HOME=/opt/jdk-9-minimalENV PATH="$PATH:$JAVA_HOME/bin"## copy app.jarVOLUME /tmpADD app.jar /app.jar#RUN sh -c 'touch /app.jar'EXPOSE 8080ENTRYPOINT java ${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom -Dspring.profiles.active=${PROFILE} -jar /app.jar 这里使用的是alpine镜像,应为它比较小,基础镜像就几M,相比ubuntu等要小很多。由于Alpine Linux使用MUSL作为标准C库,而openjdk依赖于GNU标准C库(gclib),因此需要alpine版的jdk9才可以在alpine上运行,但是目前jdk 9还没有正式的alpine镜像,只有有一个early access的版
这里我们使用dekstroza基于alpine3.6构建好的镜像dekstroza/openjdk9-alpine作为jlink的基础镜像,然后确定好工程依赖的jmods(
下面的内容会讲怎么确定),然后使用jlink构建最小的jdk运行环境.
这里的--module-path(
-p)指定依赖的模块路径；--add-modules添加root module用于分析依赖；--compress指定压缩方式，0为不压缩，1为常量字符串共享，2为zip压缩；--no-header-files指定排除头文件；--verbose用于开启trace输出。
构建并运行
mvn clean package -Dmaven.test.skip=truecd targetcp ../src/main/docker/Dockerfile .docker build -t springboot2-java9-demo .docker run --rm -p 8080:8080 \--name springboot2-java9-demo \-e PROFILE=default \springboot2-java9-demo
确定所依赖的jmod
这个目前来说还没找到现成命令/工具可以动态找出工程依赖的jmod.不过可以自己通过jdeps命令构建shell脚本来实现
copy-dependencies
org.apache.maven.plugins maven-dependency-plugin copy-dependencies prepare-package copy-dependencies ${project.build.directory}/classes/lib false false true
这里通过copy-dependencies插件把依赖jar存放到classes/lib目录下,然后使用jdeps指定这个class-path来分析app.jar(
这样做的目的主要是springboot打包出来的是fatjar,相关jar都在fatjar中，不好指定class-path)
jdeps recursive summary
➜ target git:(master) ✗ jdeps --class-path 'classes/lib/*' -recursive -summary app.jar拆分程序包: javax.annotation [jrt:/java.xml.ws.annotation, classes/lib/javax.annotation-api-1.3.1.jar, classes/lib/jsr305-1.3.9.jar]app.jar -> classes/lib/commons-lang3-3.7.jarapp.jar -> classes/lib/guava-24.0-jre.jarapp.jar -> java.baseapp.jar -> java.loggingapp.jar -> classes/lib/reactive-streams-1.0.2.jarapp.jar -> classes/lib/reactor-core-3.1.4.RELEASE.jarapp.jar -> classes/lib/rest-common-0.0.2.jarapp.jar -> classes/lib/slf4j-api-1.7.25.jarapp.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarapp.jar -> classes/lib/spring-boot-2.0.0.RC2.jarapp.jar -> classes/lib/spring-boot-autoconfigure-2.0.0.RC2.jarapp.jar -> classes/lib/spring-context-5.0.4.RELEASE.jarapp.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarapp.jar -> classes/lib/spring-web-5.0.4.RELEASE.jarapp.jar -> classes/lib/spring-webflux-5.0.4.RELEASE.jarchecker-compat-qual-2.0.0.jar -> java.basecommons-lang3-3.7.jar -> java.baseerror_prone_annotations-2.1.3.jar -> java.baseguava-24.0-jre.jar -> classes/lib/checker-compat-qual-2.0.0.jarguava-24.0-jre.jar -> classes/lib/error_prone_annotations-2.1.3.jarguava-24.0-jre.jar -> java.baseguava-24.0-jre.jar -> java.logginglogback-classic-1.2.3.jar -> java.baselogback-classic-1.2.3.jar -> java.managementlogback-classic-1.2.3.jar -> java.naminglogback-classic-1.2.3.jar -> java.xmllogback-classic-1.2.3.jar -> jdk.unsupportedlogback-classic-1.2.3.jar -> classes/lib/logback-core-1.2.3.jarlogback-classic-1.2.3.jar -> classes/lib/slf4j-api-1.7.25.jarlogback-classic-1.2.3.jar -> 找不到logback-core-1.2.3.jar -> java.baselogback-core-1.2.3.jar -> java.xmllogback-core-1.2.3.jar -> 找不到netty-buffer-4.1.21.Final.jar -> java.basenetty-buffer-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-codec-4.1.21.Final.jar -> java.basenetty-codec-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-codec-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-codec-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-codec-4.1.21.Final.jar -> 找不到netty-codec-http-4.1.21.Final.jar -> java.basenetty-codec-http-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-codec-http-4.1.21.Final.jar -> classes/lib/netty-codec-4.1.21.Final.jarnetty-codec-http-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-codec-http-4.1.21.Final.jar -> classes/lib/netty-handler-4.1.21.Final.jarnetty-codec-http-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-codec-socks-4.1.21.Final.jar -> java.basenetty-codec-socks-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-codec-socks-4.1.21.Final.jar -> classes/lib/netty-codec-4.1.21.Final.jarnetty-codec-socks-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-codec-socks-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-common-4.1.21.Final.jar -> java.basenetty-common-4.1.21.Final.jar -> java.loggingnetty-common-4.1.21.Final.jar -> jdk.unsupportednetty-common-4.1.21.Final.jar -> classes/lib/slf4j-api-1.7.25.jarnetty-common-4.1.21.Final.jar -> 找不到netty-handler-4.1.21.Final.jar -> java.basenetty-handler-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-handler-4.1.21.Final.jar -> classes/lib/netty-codec-4.1.21.Final.jarnetty-handler-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-handler-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-handler-4.1.21.Final.jar -> 找不到netty-handler-proxy-4.1.21.Final.jar -> java.basenetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-codec-4.1.21.Final.jarnetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-codec-http-4.1.21.Final.jarnetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-codec-socks-4.1.21.Final.jarnetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-handler-proxy-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-resolver-4.1.21.Final.jar -> java.basenetty-resolver-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-transport-4.1.21.Final.jar -> java.basenetty-transport-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-transport-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-transport-4.1.21.Final.jar -> classes/lib/netty-resolver-4.1.21.Final.jarnetty-transport-native-epoll-4.1.21.Final.jar -> java.basenetty-transport-native-epoll-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-transport-native-epoll-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-transport-native-epoll-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarnetty-transport-native-epoll-4.1.21.Final.jar -> classes/lib/netty-transport-native-unix-common-4.1.21.Final.jarnetty-transport-native-unix-common-4.1.21.Final.jar -> java.basenetty-transport-native-unix-common-4.1.21.Final.jar -> classes/lib/netty-buffer-4.1.21.Final.jarnetty-transport-native-unix-common-4.1.21.Final.jar -> classes/lib/netty-common-4.1.21.Final.jarnetty-transport-native-unix-common-4.1.21.Final.jar -> classes/lib/netty-transport-4.1.21.Final.jarreactive-streams-1.0.2.jar -> java.basereactor-core-3.1.4.RELEASE.jar -> java.basereactor-core-3.1.4.RELEASE.jar -> java.loggingreactor-core-3.1.4.RELEASE.jar -> classes/lib/reactive-streams-1.0.2.jarreactor-core-3.1.4.RELEASE.jar -> classes/lib/slf4j-api-1.7.25.jarreactor-core-3.1.4.RELEASE.jar -> 找不到reactor-netty-0.7.4.RELEASE.jar -> java.basereactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-buffer-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-codec-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-codec-http-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-common-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-handler-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-handler-proxy-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-resolver-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-transport-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/netty-transport-native-epoll-4.1.21.Final.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/reactive-streams-1.0.2.jarreactor-netty-0.7.4.RELEASE.jar -> classes/lib/reactor-core-3.1.4.RELEASE.jarreactor-netty-0.7.4.RELEASE.jar -> 找不到rest-common-0.0.2.jar -> java.baseslf4j-api-1.7.25.jar -> java.baseslf4j-api-1.7.25.jar -> classes/lib/logback-classic-1.2.3.jarspring-aop-5.0.4.RELEASE.jar -> java.basespring-aop-5.0.4.RELEASE.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarspring-aop-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-aop-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-beans-5.0.4.RELEASE.jar -> java.basespring-beans-5.0.4.RELEASE.jar -> java.desktopspring-beans-5.0.4.RELEASE.jar -> java.xmlspring-beans-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-beans-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-beans-5.0.4.RELEASE.jar -> 找不到spring-boot-2.0.0.RC2.jar -> java.basespring-boot-2.0.0.RC2.jar -> java.desktopspring-boot-2.0.0.RC2.jar -> java.managementspring-boot-2.0.0.RC2.jar -> java.xmlspring-boot-2.0.0.RC2.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarspring-boot-2.0.0.RC2.jar -> classes/lib/spring-context-5.0.4.RELEASE.jarspring-boot-2.0.0.RC2.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-boot-2.0.0.RC2.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-boot-2.0.0.RC2.jar -> classes/lib/spring-web-5.0.4.RELEASE.jarspring-boot-2.0.0.RC2.jar -> 找不到spring-boot-autoconfigure-2.0.0.RC2.jar -> java.basespring-boot-autoconfigure-2.0.0.RC2.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarspring-boot-autoconfigure-2.0.0.RC2.jar -> classes/lib/spring-boot-2.0.0.RC2.jarspring-boot-autoconfigure-2.0.0.RC2.jar -> classes/lib/spring-context-5.0.4.RELEASE.jarspring-boot-autoconfigure-2.0.0.RC2.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-boot-autoconfigure-2.0.0.RC2.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> java.basespring-context-5.0.4.RELEASE.jar -> java.desktopspring-context-5.0.4.RELEASE.jar -> java.instrumentspring-context-5.0.4.RELEASE.jar -> java.managementspring-context-5.0.4.RELEASE.jar -> java.namingspring-context-5.0.4.RELEASE.jar -> java.xmlspring-context-5.0.4.RELEASE.jar -> java.xml.wsspring-context-5.0.4.RELEASE.jar -> java.xml.ws.annotationspring-context-5.0.4.RELEASE.jar -> classes/lib/spring-aop-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> classes/lib/spring-expression-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-context-5.0.4.RELEASE.jar -> 找不到spring-core-5.0.4.RELEASE.jar -> java.basespring-core-5.0.4.RELEASE.jar -> java.desktopspring-core-5.0.4.RELEASE.jar -> java.sqlspring-core-5.0.4.RELEASE.jar -> java.xmlspring-core-5.0.4.RELEASE.jar -> jdk.unsupportedspring-core-5.0.4.RELEASE.jar -> classes/lib/netty-buffer-4.1.21.Final.jarspring-core-5.0.4.RELEASE.jar -> classes/lib/netty-common-4.1.21.Final.jarspring-core-5.0.4.RELEASE.jar -> classes/lib/reactive-streams-1.0.2.jarspring-core-5.0.4.RELEASE.jar -> classes/lib/reactor-core-3.1.4.RELEASE.jarspring-core-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-core-5.0.4.RELEASE.jar -> 找不到spring-expression-5.0.4.RELEASE.jar -> java.basespring-expression-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-expression-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-jcl-5.0.4.RELEASE.jar -> java.basespring-jcl-5.0.4.RELEASE.jar -> java.loggingspring-jcl-5.0.4.RELEASE.jar -> classes/lib/slf4j-api-1.7.25.jarspring-jcl-5.0.4.RELEASE.jar -> 找不到spring-web-5.0.4.RELEASE.jar -> java.basespring-web-5.0.4.RELEASE.jar -> classes/lib/netty-buffer-4.1.21.Final.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/netty-codec-http-4.1.21.Final.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/netty-transport-4.1.21.Final.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/reactive-streams-1.0.2.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/reactor-core-3.1.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/reactor-netty-0.7.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/spring-beans-5.0.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/spring-context-5.0.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-web-5.0.4.RELEASE.jar -> 找不到spring-webflux-5.0.4.RELEASE.jar -> java.basespring-webflux-5.0.4.RELEASE.jar -> classes/lib/reactive-streams-1.0.2.jarspring-webflux-5.0.4.RELEASE.jar -> classes/lib/reactor-core-3.1.4.RELEASE.jarspring-webflux-5.0.4.RELEASE.jar -> classes/lib/spring-context-5.0.4.RELEASE.jarspring-webflux-5.0.4.RELEASE.jar -> classes/lib/spring-core-5.0.4.RELEASE.jarspring-webflux-5.0.4.RELEASE.jar -> classes/lib/spring-jcl-5.0.4.RELEASE.jarspring-webflux-5.0.4.RELEASE.jar -> classes/lib/spring-web-5.0.4.RELEASE.jar
由于classes/lib/log4j-api-2.10.0.jar是multi-release的需特殊指定multi-release 9,但是由于使用的是recursive,因此这里先临时删掉,再分析 通过输出找出java,jdk开头的,去重之后得到所需的jmods
java.base,java.logging,java.xml,jdk.unsupported,java.sql,java.desktop,java.management,java.naming,java.instrument
jdk-internals
➜ target git:(master) ✗ jdeps --class-path 'classes/lib/*' -recursive --jdk-internals app.jar拆分程序包: javax.annotation [jrt:/java.xml.ws.annotation, classes/lib/javax.annotation-api-1.3.1.jar, classes/lib/jsr305-1.3.9.jar]fastjson-1.2.35.jar -> java.base com.alibaba.fastjson.serializer.AnnotationSerializer -> sun.reflect.annotation.AnnotationType JDK internal API (java.base)guava-24.0-jre.jar -> jdk.unsupported com.google.common.cache.Striped64 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.cache.Striped64$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.cache.Striped64$Cell -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.LittleEndianByteArray$UnsafeByteArray -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.LittleEndianByteArray$UnsafeByteArray$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.LittleEndianByteArray$UnsafeByteArray$2 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.LittleEndianByteArray$UnsafeByteArray$3 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.Striped64 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.Striped64$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.hash.Striped64$Cell -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.util.concurrent.AbstractFuture$UnsafeAtomicHelper -> sun.misc.Unsafe JDK internal API (jdk.unsupported) com.google.common.util.concurrent.AbstractFuture$UnsafeAtomicHelper$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported)logback-classic-1.2.3.jar -> jdk.unsupported ch.qos.logback.classic.spi.PackagingDataCalculator -> sun.reflect.Reflection JDK internal API (jdk.unsupported)lombok-1.16.20.jar -> jdk.compiler lombok.javac.apt.Processor -> com.sun.tools.javac.processing.JavacFiler JDK internal API (jdk.compiler) lombok.javac.apt.Processor -> com.sun.tools.javac.processing.JavacProcessingEnvironment JDK internal API (jdk.compiler) lombok.javac.apt.Processor -> com.sun.tools.javac.util.Context JDK internal API (jdk.compiler) lombok.javac.apt.Processor -> com.sun.tools.javac.util.Options JDK internal API (jdk.compiler)netty-common-4.1.21.Final.jar -> jdk.unsupported io.netty.util.internal.CleanerJava9 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.PlatformDependent$Mpsc$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.PlatformDependent0 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.PlatformDependent0$1 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.PlatformDependent0$2 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.PlatformDependent0$3 -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueConsumerNodeRef -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.BaseLinkedQueueProducerNodeRef -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.BaseMpscLinkedArrayQueueProducerFields -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.LinkedQueueNode -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueConsumerIndexField -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerIndexField -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueueProducerLimitField -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.util.UnsafeAccess -> sun.misc.Unsafe JDK internal API (jdk.unsupported) io.netty.util.internal.shaded.org.jctools.util.UnsafeRefArrayAccess -> sun.misc.Unsafe JDK internal API (jdk.unsupported)netty-handler-4.1.21.Final.jar -> java.base io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.util.ObjectIdentifier JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.AlgorithmId JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateAlgorithmId JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateIssuerName JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateSerialNumber JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateSubjectName JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateValidity JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateVersion JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.CertificateX509Key JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.X500Name JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.X509CertImpl JDK internal API (java.base) io.netty.handler.ssl.util.OpenJdkSelfSignedCertGenerator -> sun.security.x509.X509CertInfo JDK internal API (java.base)objenesis-2.6.jar -> jdk.unsupported org.objenesis.instantiator.sun.UnsafeFactoryInstantiator -> sun.misc.Unsafe JDK internal API (jdk.unsupported) org.objenesis.instantiator.util.ClassDefinitionUtils -> sun.misc.Unsafe JDK internal API (jdk.unsupported) org.objenesis.instantiator.util.UnsafeUtils -> sun.misc.Unsafe JDK internal API (jdk.unsupported)reactor-core-3.1.4.RELEASE.jar -> jdk.unsupported reactor.core.publisher.MultiProducerRingBuffer -> sun.misc.Unsafe JDK internal API (jdk.unsupported) reactor.core.publisher.RingBuffer -> sun.misc.Unsafe JDK internal API (jdk.unsupported) reactor.core.publisher.RingBufferFields -> sun.misc.Unsafe JDK internal API (jdk.unsupported) reactor.core.publisher.UnsafeSequence -> sun.misc.Unsafe JDK internal API (jdk.unsupported) reactor.core.publisher.UnsafeSupport -> sun.misc.Unsafe JDK internal API (jdk.unsupported)spring-core-5.0.4.RELEASE.jar -> jdk.unsupported org.springframework.objenesis.instantiator.sun.UnsafeFactoryInstantiator -> sun.misc.Unsafe JDK internal API (jdk.unsupported) org.springframework.objenesis.instantiator.util.ClassDefinitionUtils -> sun.misc.Unsafe JDK internal API (jdk.unsupported) org.springframework.objenesis.instantiator.util.UnsafeUtils -> sun.misc.Unsafe JDK internal API (jdk.unsupported)警告: 不支持 JDK 内部 API, 它们专用于通过不兼容方式来删除或更改的 JDK 实现, 可能会损坏您的应用程序。请修改您的代码, 消除与任何 JDK 内部 API 的相关性。有关 JDK 内部 API 替换的最新更新, 请查看:https://wiki.openjdk.java.net/display/JDK8/Java+Dependency+Analysis+ToolJDK 内部 API 建议的替换---------- -----com.sun.tools.javac.processing.JavacFiler Use javax.tools and javax.lang.model @since 1.6com.sun.tools.javac.processing.JavacProcessingEnvironment Use javax.tools and javax.lang.model @since 1.6com.sun.tools.javac.util.Context Use javax.tools and javax.lang.model @since 1.6com.sun.tools.javac.util.Options Use javax.tools and javax.lang.model @since 1.6sun.misc.Unsafe See http://openjdk.java.net/jeps/260sun.reflect.Reflection Use java.lang.StackWalker @since 9sun.reflect.annotation.AnnotationType Removed. See http://openjdk.java.net/jeps/260sun.security.x509.X500Name Use javax.security.auth.x500.X500Principal @since 1.4
可以发现netty,netty等还使用了sun.misc.Unsafe,这个被归到了jdk.unsupported,顾名思义就是不建议用户程序调用,它原本只想让oracle jdk team来使用.
小结
一个jdk8的镜像，使用ubuntu可能要用到六七百M，使用alpine的话要大概200M.通过jlink之后这个例子的java9大小为63.22M，加上springboot2的fatjar一共87.54M.
目前本文所用的方式还有诸多不足,主要有如下几点:
- 使用MUSL编译版本的openjdk目前只有Early-Access build版本还没有正式发布
- dockerfile指定的jmod有待通过脚本去解析依赖jar包动态确定
- springboot工程及诸多第三方类库还没有使用java9的模块系统，虽然java9通过unnamed module来支持java9以前的jar包，但迁移到java9毕竟是最好的
- maven相关的plugin比如jlink,jmod目前还只是pre-release,还没有正式发布
jdk9的周边设施还有待进一步完善