Support Java 9

[snicoll]

Spring Boot master (2.0.0.BUILD-SNAPSHOT) doesn't currently build with JDK9, see the dedicated job

• AgentAttacher does not work on JDK9 AgentAttacher does not work on JDK9 #9139
• Antlib support is broken with JDK9 Antlib support is broken with Java 9 #9140
• ModifiedClassPathRunner is broken with JDK9 ModifiedClassPathRunner is broken with Java 9 #9142

[snicoll]

The current build doesn't exhibit the same issue. I'll investigate that a bit more.

[snicoll]

We need to find a different way to extract the default values for the meta-data as we're using a proprietary API.

java.lang.IllegalAccessException: class org.springframework.boot.configurationprocessor.fieldvalues.javac.Trees cannot access class com.sun.tools.javac.api.JavacTrees (in module jdk.compiler) because module jdk.compiler does not export com.sun.tools.javac.api to unnamed module @5a7fe64f

[snicoll]

[ERROR] /Users/snicoll/workspace/pivotal/spring-boot/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/tunnel/server/RemoteDebugPortProvider.java:[51,43] cannot find symbol
  symbol:   class VMSupport
  location: package sun.misc

[philwebb]

java.lang.IllegalAccessException: class org.springframework.boot.configurationprocessor.fieldvalues.javac.Trees cannot access class com.sun.tools.javac.api.JavacTrees (in module jdk.compiler) because module jdk.compiler does not export com.sun.tools.javac.api to unnamed module @5a7fe64f

Yikes, this might be an issue. It might be worth asking on the JDK mailing list if there's any official way to do this.

[snicoll]

I've created a thread on jigsaw-dev about this.

[snicoll]

There are also additional runtime issues (see #7565 for more details)

[snicoll]

LaunchedURLClassLoaderTests#resolveFromNested does not work with Java9 since nested.jar!/3.dat isn't identified as a valid resource anymore. I haven't found any information about this yet.

[snicoll]

IJ also (wrongly) refuses to compile SignalUtils. I've reported IDEA-167758

[wilkinsona]

LaunchedURLClassLoaderTests#resolveFromNested fails because org.springframework.boot.loader.jar.Handler isn't being used. This is the class that we configure to be the URLStreamHandler for jar: URLs. Unfortunately, this due to an optimisation for jar:file: URLs. It creates a java.util.jar.JarFile directly from a File rather than going via a JarURLConnection. Similar logic appears to be in Java 8 so it's not yet clear why the behaviour has changed.

[snicoll]

Ok we're further now. Next is we need to switch to Maven assembly plugin 3.0.1 but we need to make the release happen first. I am on it.

[robinst]

Friendly ping :). What's the status of this?

[douglarek]

Will Spring boot 1.5.x support java 9 ?

[wilkinsona]

@douglarek No

[wilkinsona]

@robinst The status is all on this page. The issue is open and scheduled for 2.0 M5.

[juanmbellini]

Don't know if this comment should be here or where, but I have just upgrade to java 9 and couldn't run a Spring Boot Application.
This is a Spring Boot Application using Jersey, Data and Security starters.

First of all the following was printed in the console when trying to run the app.

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by ...to field ...
WARNING: Please consider reporting this to the maintainers of  org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

Then the app didn't start, printing the following stacktrace

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.jersey.ResourceConfigCustomizer]: Factory method 'resourceConfigCustomizer' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlElement
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
	... 57 common frames omitted
Caused by: java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlElement
	at com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector.<init>(JaxbAnnotationIntrospector.java:139)
	at com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector.<init>(JaxbAnnotationIntrospector.java:126)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer$ObjectMapperCustomizer.addJaxbAnnotationIntrospector(JerseyAutoConfiguration.java:266)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer$ObjectMapperCustomizer.access$200(JerseyAutoConfiguration.java:262)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer.addJaxbAnnotationIntrospectorIfPresent(JerseyAutoConfiguration.java:258)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer.resourceConfigCustomizer(JerseyAutoConfiguration.java:244)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer$$EnhancerBySpringCGLIB$$a15c1d0c.CGLIB$resourceConfigCustomizer$0(<generated>)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer$$EnhancerBySpringCGLIB$$a15c1d0c$$FastClassBySpringCGLIB$$3126cdea.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358)
	at org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration$JacksonResourceConfigCustomizer$$EnhancerBySpringCGLIB$$a15c1d0c.resourceConfigCustomizer(<generated>)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
	... 58 common frames omitted
Caused by: java.lang.ClassNotFoundException: javax.xml.bind.annotation.XmlElement
	at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:563)
	at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:94)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
	... 74 common frames omitted

Making some research on google I found that Java EE modules must be explicitly included, so I created the module-info.java file, including the corresponding module. But after that, any class of Spring couldn't be located.

[cemo]

@juanmbellini There are multiple ways to fix this issue but I preferred explicitly declaring these dependencies in my project.

    <jaxb.version>2.3.0</jaxb.version>
    <jaxws.version>2.3.0</jaxws.version>

and

      <dependency>
        <groupId>javax.annotation</groupId>
        <artifactId>javax.annotation-api</artifactId>
        <version>${javax-annotation.version}</version>
      </dependency>
      <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>${jaxb.version}</version>
      </dependency>
      <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>${jaxb.version}</version>
      </dependency>
      <dependency>
        <groupId>javax.xml.ws</groupId>
        <artifactId>jaxws-api</artifactId>
        <version>${jaxws.version}</version>
      </dependency>
      <dependency>
        <groupId>com.sun.xml.ws</groupId>
        <artifactId>jaxws-rt</artifactId>
        <version>${jaxws.version}</version>
      </dependency>

As you stated these modules are part of java ee and will be removed in the future. In the future you will need to definitely add these dependencies.

I have not tested in a detailed way but spring boot 1.5.x seems working with JDK9 as well. Please note that I have not added module info files yet. I had just added some dependencies.

[vnobo]

spring support java 9 ,It will take some time to support! so wait wait wait.....

[snicoll]

One important piece at this point is to update AspectJ as 1.9 is not GA yet and is definitely required to run with Java 9

<aspectj.version>1.9.0.BETA-7</aspectj.version>

(available from repo.spring.io/milestone)

[snicoll]

Unless we manage to get a workaround, it looks like there is a bug in Maven that prevents us to property test with Java9. I've opened SUREFIRE-1424.

[snicoll]

Liquibase does not work with Java9 yet. I've created CORE-3114

[snicoll]

With well identified limitations the build now passes with Java 9. I've started a wiki page to gathers some of the gotchas.

[juliuskrah]

@juanmbellini you can try by adding the modules.

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <configuration>
    <jvmArguments>--add-modules java.xml.bind,java.xml.ws,java.xml.ws.annotation</jvmArguments>
  </configuration>
</plugin>