1、異常提示：
DEBUG [restartedMain] io.netty.util.internal.PlatformDependent0 (261)- direct buffer constructor: unavailable
java.lang.UnsupportedOperationException: Reflective setAccessible(true) disabled
at io.netty.util.internal.ReflectionUtil.trySetAccessible(ReflectionUtil.java:31)
at io.netty.util.internal.PlatformDependent0$4.run(PlatformDependent0.java:233)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at io.netty.util.internal.PlatformDependent0.<clinit>(PlatformDependent0.java:227)
at io.netty.util.internal.PlatformDependent.isAndroid(PlatformDependent.java:289)
at io.netty.util.internal.PlatformDependent.<clinit>(PlatformDependent.java:92)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:109)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:218)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:197)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:179)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:163)
at io.lettuce.core.resource.DefaultClientResources.<init>(DefaultClientResources.java:167)
at io.lettuce.core.resource.DefaultClientResources$Builder.build(DefaultClientResources.java:530)
at io.lettuce.core.resource.DefaultClientResources.create(DefaultClientResources.java:231)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.lettuceClientResources(LettuceConnectionConfiguration.java:66)
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:566)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:484)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
at com.artup.boss.StartBossApplication.main(StartBossApplication.java:23)
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:566)
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
2020-06-16 09:29:18,743 DEBUG [restartedMain] io.netty.util.internal.PlatformDependent0 (326)- java.nio.Bits.unaligned: available, true
2020-06-16 09:29:18,758 DEBUG [restartedMain] io.netty.util.internal.PlatformDependent0 (385)- jdk.internal.misc.Unsafe.allocateUninitializedArray(int): unavailable
java.lang.IllegalAccessException: class io.netty.util.internal.PlatformDependent0$6 cannot access class jdk.internal.misc.Unsafe (in module java.base) because module java.base does not export jdk.internal.misc to unnamed module @1b817008
at java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:361)
at java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:591)
at java.base/java.lang.reflect.Method.invoke(Method.java:558)
at io.netty.util.internal.PlatformDependent0$6.run(PlatformDependent0.java:347)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at io.netty.util.internal.PlatformDependent0.<clinit>(PlatformDependent0.java:338)
at io.netty.util.internal.PlatformDependent.isAndroid(PlatformDependent.java:289)
at io.netty.util.internal.PlatformDependent.<clinit>(PlatformDependent.java:92)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:109)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:218)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:197)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:179)
at io.netty.util.HashedWheelTimer.<init>(HashedWheelTimer.java:163)
at io.lettuce.core.resource.DefaultClientResources.<init>(DefaultClientResources.java:167)
at io.lettuce.core.resource.DefaultClientResources$Builder.build(DefaultClientResources.java:530)
at io.lettuce.core.resource.DefaultClientResources.create(DefaultClientResources.java:231)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.lettuceClientResources(LettuceConnectionConfiguration.java:66)
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:566)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:484)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
at com.artup.boss.StartBossApplication.main(StartBossApplication.java:23)
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:566)
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
2、分析：
這是個 debug，並不是 error，一般對我們的系統運行不會產生影響，推測作者是想提醒我們 JDK 版本的編號可能對我們的存在潛在的風險，JDK 1.8 之前（含 JDK 1.8）使用了不安全的 API，自 JDK 9（含 JDK 9）已經廢棄，提醒我們注意。
針對這個現象我們通過設置 JVM 參數使此 debug 不再輸出。
3、解決辦法：
在 Eclipse 的 VM 中加入如下參數：
--add-opens java.base/jdk.internal.misc=ALL-UNNAMED
-Dio.netty.tryReflectionSetAccessible=true
--illegal-access=warn （選填）
在 CentOS 中的啟動方式為：
nohup java -jar --add-opens java.base/jdk.internal.misc=ALL-UNNAMED -Dio.netty.tryReflectionSetAccessible=true 項目名 >> 日志地址 &