JDK 9环境下使用Apache Ignite遇初始化异常求助

问题复现 #

你的最简测试用例：

package no.ovstetun.ignite;

import org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi;
import org.junit.Test;

public class FailingIgniteTest {
    @Test
    public void failingIgnite() {
        TcpDiscoverySpi discoverySpi = new TcpDiscoverySpi();
    }
}

运行时抛出的错误堆栈：

java.lang.ExceptionInInitializerError
    at org.apache.ignite.internal.util.IgniteUtils.<clinit>(IgniteUtils.java:769)
    at org.apache.ignite.spi.IgniteSpiAdapter.<init>(IgniteSpiAdapter.java:119)
    at org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi.<init>(TcpDiscoverySpi.java:231)
    at no.nrk.mdb.common.infrastructure.ignite.IgniteConfigurationTest.failingIgnite(IgniteConfigurationTest.java:10)
    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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.RuntimeException: jdk.internal.misc.JavaNioAccess class is unavailable.
    at org.apache.ignite.internal.util.GridUnsafe.javaNioAccessObject(GridUnsafe.java:1453)
    at org.apache.ignite.internal.util.GridUnsafe.<clinit>(GridUnsafe.java:112)
    ... 26 more
Caused by: java.lang.IllegalAccessException: class org.apache.ignite.internal.util.GridUnsafe cannot access class jdk.internal.misc.SharedSecrets (in module java.base) because module java.base does not export jdk.internal.misc to unnamed module @31ef45e3
    at java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:361)
    at java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:589)
    at java.base/java.lang.reflect.Method.invoke(Method.java:556)
    at org.apache.ignite.internal.util.GridUnsafe.javaNioAccessObject(GridUnsafe.java:1450)
    ... 27 more

解决步骤 #

这个错误是JDK 9引入的模块系统（JPMS）导致的：java.base模块中的内部API默认不再对外暴露，而Ignite的GridUnsafe类依赖这些API做底层优化，所以需要显式开放访问权限。

1. 添加必要的JVM启动参数
   在你的测试运行器或应用启动脚本中加入以下参数：

   --add-exports=java.base/jdk.internal.misc=ALL-UNNAMED
   --add-exports=java.base/sun.nio.ch=ALL-UNNAMED
   --add-exports=jdk.unsupported/sun.misc=ALL-UNNAMED
   --add-exports=jdk.unsupported/sun.reflect=ALL-UNNAMED
   

   这些参数会让java.base和jdk.unsupported模块把指定的内部包导出给未命名模块（因为Ignite 2.4.0/2.5.0还没有适配模块化）。

2. 升级Ignite版本（推荐）
   Ignite从2.6.0版本开始对JDK 9+有了更好的兼容性支持，虽然还是可能需要部分上述参数，但升级后能减少潜在的其他兼容性问题。如果条件允许，建议升级到2.6.0及以上版本。

错误原因解释 #

JDK 9的模块化系统（JPMS）将JDK的代码拆分为多个模块，并且默认禁止外部代码访问模块中的内部包（比如jdk.internal.misc）。Ignite的GridUnsafe类通过反射调用这些内部API来实现高性能的内存操作和NIO优化，这在JDK 8及以前是允许的，但JDK 9开始被限制，所以抛出了IllegalAccessException，进而触发了初始化异常。

内容的提问来源于stack exchange，提问作者Trond Marius Øvstetun