将Spring Boot 2用于IoT应用程序，我注意到Spring的启动时间不成比例地缓慢。该平台是Raspberry PI 2B - 当然，这将比PC慢得多。对于正常的代码执行，我测量的差异为20x到50x。
如果我使用了我测量过的最高因子（50x），我预计启动时间不会超过当前状态的一半。到目前为止，我试过了：
我的初步结论是加载bean会占用所有CPU周期。我想初始化一个bean不应该花费几秒钟，但确实如此。这可能是什么瓶颈？我可以以任何方式让Spring加载更快吗？
以下是PC输出的第一部分：
2018-01-06 13:43:03.462 INFO 9144 --- [ main] c.e.b.BasestationApplicationKt : Starting BasestationApplicationKt on GPC with PID 9144 (C:\Data\Code\app\git\basestation\out\production\classes started by User in C:\Data\Code\app\git)
2018-01-06 13:43:03.471 INFO 9144 --- [ main] c.e.b.BasestationApplicationKt : The following profiles are active: dev
2018-01-06 13:43:03.637 INFO 9144 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@294e5088: startup date [Sat Jan 06 13:43:03 CET 2018]; root of context hierarchy
2018-01-06 13:43:05.578 INFO 9144 --- [ main] org.xnio : XNIO version 3.3.8.Final
2018-01-06 13:43:05.600 INFO 9144 --- [ main] org.xnio.nio : XNIO NIO Implementation Version 3.3.8.Final
2018-01-06 13:43:05.695 WARN 9144 --- [ main] io.undertow.websockets.jsr : UT026009: XNIO worker was not set on WebSocketDeploymentInfo, the default worker will be used
2018-01-06 13:43:05.695 WARN 9144 --- [ main] io.undertow.websockets.jsr : UT026010: Buffer pool was not set on WebSocketDeploymentInfo, the default pool will be used
2018-01-06 13:43:05.721 INFO 9144 --- [ main] io.undertow.servlet : Initializing Spring embedded WebApplicationContext
2018-01-06 13:43:05.722 INFO 9144 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 2088 ms
2018-01-06 13:43:05.851 INFO 9144 --- [ main] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2018-01-06 13:43:05.857 INFO 9144 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-01-06 13:43:07.323 INFO 9144 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/],methods=[GET]}" onto public com.app.basestation.model.Message com.app.basestation.BasestationController.home()
2018-01-06 13:43:07.330 INFO 9144 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2018-01-06 13:43:07.349 INFO 9144 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2018-01-06 13:43:07.509 INFO 9144 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@294e5088: startup date [Sat Jan 06 13:43:03 CET 2018]; root of context hierarchy
2018-01-06 13:43:08.519 INFO 9144 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-01-06 13:43:08.553 INFO 9144 --- [ main] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 2147483647
2018-01-06 13:43:08.678 INFO 9144 --- [ main] o.s.b.w.e.u.UndertowServletWebServer : Undertow started on port(s) 11112 (http)
PI的输出：
2018-01-06 12:48:41.689 INFO 1 --- [ main] c.e.b.BasestationApplicationKt : Starting BasestationApplicationKt on ubuntu with PID 1 (/app.jar started by root in /)
2018-01-06 12:48:42.019 INFO 1 --- [ main] c.e.b.BasestationApplicationKt : The following profiles are active: prd
2018-01-06 12:48:49.827 INFO 1 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@128c152: startup date [Sat Jan 06 12:48:49 UTC 2018]; root of context hierarchy
2018-01-06 12:54:05.276 INFO 1 --- [ main] org.xnio : XNIO version 3.3.8.Final
2018-01-06 12:54:08.404 INFO 1 --- [ main] org.xnio.nio : XNIO NIO Implementation Version 3.3.8.Final
2018-01-06 12:54:15.847 WARN 1 --- [ main] io.undertow.websockets.jsr : UT026009: XNIO worker was not set on WebSocketDeploymentInfo, the default worker will be used
2018-01-06 12:54:15.852 WARN 1 --- [ main] io.undertow.websockets.jsr : UT026010: Buffer pool was not set on WebSocketDeploymentInfo, the default pool will be used
2018-01-06 12:54:19.930 INFO 1 --- [ main] io.undertow.servlet : Initializing Spring embedded WebApplicationContext
2018-01-06 12:54:19.934 INFO 1 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 330155 ms
2018-01-06 12:54:42.544 INFO 1 --- [ main] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2018-01-06 12:54:43.206 INFO 1 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-01-06 12:57:18.683 INFO 1 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/],methods=[GET]}" onto public com.app.basestation.model.Message com.app.basestation.BasestationController.home()
2018-01-06 12:57:19.734 INFO 1 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2018-01-06 12:57:19.758 INFO 1 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2018-01-06 12:57:44.597 INFO 1 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@128c152: startup date [Sat Jan 06 12:48:49 UTC 2018]; root of context hierarchy
2018-01-06 12:59:36.677 INFO 1 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-01-06 12:59:37.807 INFO 1 --- [ main] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 2147483647
2018-01-06 12:59:42.664 INFO 1 --- [ main] o.s.b.w.e.u.UndertowServletWebServer : Undertow started on port(s) 11112 (http)
答案 0 :(得分：0)
我转移到了一个新的图像：Oracle JDK而不是OpenJDK，如@snodnipper建议的那样。
我必须做的一些事情包括安装比标准存储库中可用的更新版本的Java 8。这是最终为我工作的Dockerfile，现在应用程序在2分钟内启动。
FROM resin/raspberrypi3-buildpack-deps:jessie-scm
ENV LANG C.UTF-8
ENV JAVA_HOME /usr/lib/jvm/java-8-oracle
RUN ["cross-build-start"]
RUN echo "deb http://archive.raspberrypi.org/debian/ jessie main ui staging" > /etc/apt/sources.list.d/raspi.list
RUN rm -f /usr/bin/entry.sh
RUN wget -qO - http://archive.raspberrypi.org/debian/raspberrypi.gpg.key | apt-key add -
RUN { \
echo '#!/bin/bash'; \
echo 'set -e'; \
echo; \
echo 'dirname "$(dirname "$(readlink -f "$(which javac || which java)")")"'; \
} > /usr/local/bin/docker-java-home && \
chmod +x /usr/local/bin/docker-java-home
RUN apt-key adv --recv-key --keyserver keyserver.ubuntu.com C2518248EEA14886 && \
echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main" >> /etc/apt/sources.list.d/raspi.list
RUN set -x && \
apt-get update && \
apt-cache madison oracle-java8-installer && \
echo debconf shared/accepted-oracle-license-v1-1 select true | debconf-set-selections && \
apt-get install -y oracle-java8-installer oracle-java8-set-default && \
rm -rf /var/lib/apt/lists/* && \
[ "$JAVA_HOME" = "$(docker-java-home)" ]
RUN [ "cross-build-end" ]
ADD build/libs/app-0.0.1-SNAPSHOT.jar /app.jar
ENV JAVA_OPTS=""
ENTRYPOINT exec java $JAVA_OPTS -Djava.security.egd=file:/dev/./urandom -jar /app.jar