I'm using Android Studio and have an AppEngine Backend module that uses Spring 4. This has worked just fine in the past.
However, after an update of Android Studio (now v. 2.2.3), running the backend fails with the following error:
WARNING: Error starting handlers
java.lang.NoClassDefFoundError: java.lang.reflect.Parameter is a restricted class. Please see the Google App Engine developer's guide for more details.
at com.google.appengine.tools.development.agent.runtime.Runtime.reject(Runtime.java:50)
at org.springframework.core.StandardReflectionParameterNameDiscoverer.getParameterNames(StandardReflectionParameterNameDiscoverer.java:56)
at org.springframework.core.PrioritizedParameterNameDiscoverer.getParameterNames(PrioritizedParameterNameDiscoverer.java:65)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:182)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1139)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1042)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:268)
at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:284)
at com.google.appengine.tools.development.AutomaticInstanceHolder.startUp(AutomaticInstanceHolder.java:26)
at com.google.appengine.tools.development.AbstractModule.startup(AbstractModule.java:87)
at com.google.appengine.tools.development.Modules.startup(Modules.java:105)
at com.google.appengine.tools.development.DevAppServerImpl.doStart(DevAppServerImpl.java:262)
at com.google.appengine.tools.development.DevAppServerImpl.access$000(DevAppServerImpl.java:45)
at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:217)
at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:215)
at java.security.AccessController.doPrivileged(Native Method)
at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:215)
at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:277)
at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:47)
at com.google.appengine.tools.development.DevAppServerMain.run(DevAppServerMain.java:225)
at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:216)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
I expect the underlying cause to be that java.lang.reflect.Parameter
is a Java 8 class, and AppEngine only supports Java 7.
In my backend.gradle file, I have the following top-level compatibility statements which should address this:
sourceCompatibility = JavaVersion.VERSION_1_7
targetCompatibility = JavaVersion.VERSION_1_7
In my top-level build.gradle file, I also have:
allprojects {
...
tasks.withType(JavaCompile) {
sourceCompatibility = JavaVersion.VERSION_1_7
targetCompatibility = JavaVersion.VERSION_1_7
}
}
However, this has no effect.
I tried instead to downgrade to JDK 7 using Android Studio settings (File -> Project Structure -> SDK location -> JDK location), but it won't let me specify a JDK below version 8.
Is there another way to force Spring to target Java 7? Or am I missing something obvious?
Any suggestions would be much appreciated.