小编Vin*_*nay的帖子

执行时gradlew appengineRun，我始终得到：

Starting a Gradle Daemon (subsequent builds will be faster)
Mar 26, 2018 5:47:48 PM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
2018-03-26 17:47:51.665:INFO::main: Logging initialized @3872ms
2018-03-26 17:47:53.727:INFO:oejs.Server:main: jetty-9.3.18.v20170406
2018-03-26 17:48:01.040:WARN:oeja.ClassInheritanceHandler:qtp99347477-18:
java.lang.NullPointerException
    at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
    at org.eclipse.jetty.annotations.ClassInheritanceHandler.addToInheritanceMap(ClassInheritanceHandler.java:72)
    at org.eclipse.jetty.annotations.ClassInheritanceHandler.handle(ClassInheritanceHandler.java:58)
    at org.eclipse.jetty.annotations.AnnotationParser$MyClassVisitor.visit(AnnotationParser.java:476)
    at org.objectweb.asm.ClassReader.accept(ClassReader.java:650)
    at org.objectweb.asm.ClassReader.accept(ClassReader.java:525)
    at org.eclipse.jetty.annotations.AnnotationParser.scanClass(AnnotationParser.java:978)
    at org.eclipse.jetty.annotations.AnnotationParser.parseJarEntry(AnnotationParser.java:958)
    at org.eclipse.jetty.annotations.AnnotationParser.parseJar(AnnotationParser.java:902)
    at org.eclipse.jetty.annotations.AnnotationParser.parse(AnnotationParser.java:851)
    at org.eclipse.jetty.annotations.AnnotationConfiguration$ParserTask.call(AnnotationConfiguration.java:163)
    at org.eclipse.jetty.annotations.AnnotationConfiguration$1.run(AnnotationConfiguration.java:546)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:671)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:589)
    at java.lang.Thread.run(Thread.java:745)
2018-03-26 17:48:01.087:WARN:oeja.ClassInheritanceHandler:qtp99347477-19: …

我正在尝试用 Jetty 替换 Tomcat，作为我的嵌入式 servlet 容器。然后需要使用EmbeddedServletContainerCustomizer()来配置将80端口的请求重定向到443端口（HTTPS）。但是我一开始就被这些gradlew构建错误困住了：

RedirectHttpToHttpsOnJettyConfig.java:7: 错误：包 org.springframework.boot.context.embedded 不存在

导入 org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer；

RedirectHttpToHttpsOnJettyConfig.java:8: 错误：包 org.springframework.boot.context.embedded 不存在

导入 org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer;

RedirectHttpToHttpsOnJettyConfig.java:9: 错误：包 org.springframework.boot.context.embedded.jetty 不存在

导入 org.springframework.boot.context.embedded.jetty.JettyEmbeddedServletContainerFactory；

RedirectHttpToHttpsOnJettyConfig.java:10: 错误：包 org.springframework.boot.context.embedded.jetty 不存在

导入 org.springframework.boot.context.embedded.jetty.JettyServerCustomizer；

...

这是我的 build.gradle：

buildscript {
    ext {
        springBootVersion = '2.0.0.BUILD-SNAPSHOT'
    }
    repositories {
        mavenCentral()
        maven { url "https://repo.spring.io/snapshot" }
        maven { url "https://repo.spring.io/milestone" }
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
    }
}

apply plugin: 'java'
apply plugin: 'war'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

ext['thymeleaf.version'] = '3.0.9.RELEASE'

war { …