In context of the issue reported in JDK-8362268, calling SaslOutputStream.write(...) on a closed SaslOutputStream instance leads to a NullPointerException like below:

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "org.ietf.jgss.GSSContext.wrap(byte[], int, int, org.ietf.jgss.MessageProp)" because "this.secCtx" is null
    at jdk.security.jgss/com.sun.security.sasl.gsskerb.GssKrb5Base.wrap(GssKrb5Base.java:140)
    at java.naming/com.sun.jndi.ldap.sasl.SaslOutputStream.write(SaslOutputStream.java:89)

The implementation in SaslOutputStream should be updated to match the specification of OutputStream.write() which specifies an IOException to be thrown in such cases.