RFR: 8364227: MBeanServer registerMBean throws NPE [v2]

[Kevin Walls]

> A long-standing omission where MBeanServer.registerMBean documents exception behaviour, but we actually throw an NPE.  We should recognise a null object and return the wrapped exception we document.
> 
> This wrapping behaviour is common elsewhere in this area, e.g. unregisterMBean which checks for a null name and throws RuntimeOperationsException.
> 
> Docs:
> https://docs.oracle.com/en/java/javase/24/docs/api/java.management/javax/management/MBeanServer.html#registerMBean(java.lang.Object,javax.management.ObjectName)
> 
> Throws:
> RuntimeOperationsException - Wraps a java.lang.IllegalArgumentException: The object passed in parameter is null or no object name is specified.
> 
> 
> Current behaviour:
> 
> 
> $ java MBS_NPE.java
> Exception in thread "main" java.lang.NullPointerException: Cannot invoke "Object.getClass()" because "object" is null
>         at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:296)
>         at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:511)
>         at MBS_NPE.main(MBS_NPE.java:11)
> 
> 
> Should be changed to:
> 
> 
> $ java MBS_NPE.java
> javax.management.RuntimeOperationsException: Exception occurred trying to register the MBean
>         at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:297)
>         at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:511)
>         at MBS_NPE.main(MBS_NPE.java:11)
>         at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
>         at java.base/java.lang.reflect.Method.invoke(Method.java:565)
>         at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.execute(SourceLauncher.java:258)
>         at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.run(SourceLauncher.java:138)
>         at jdk.compiler/com.sun.tools.javac.launcher.SourceLauncher.main(SourceLauncher.java:76)
> Caused by: java.lang.IllegalArgumentException: Object cannot be null
>         at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:295)
>         ... 7 more

Kevin Walls has updated the pull request incrementally with two additional commits since the last revision:

 - comment update
 - Add test for exceptions thrown in response to null params.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/26548/files
  - new: https://git.openjdk.org/jdk/pull/26548/files/3d501c7b..82f2a8d7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26548&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26548&range=00-01

  Stats: 189 lines in 1 file changed: 189 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26548.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26548/head:pull/26548

PR: https://git.openjdk.org/jdk/pull/26548