8u45 and the JRE expiration date

The JRE expires when a new security update becomes available. 8u45 will expire on July 14, 2015. 8u45 contains a new blacklist JAR entry.

Signing Jar Files with the "JJA" Sequence

Jar files can be signed using the following syntax [henceforth referred to as the "JJA" sequence]:

jarsigner jar-file alias

The alias identifies the private key used to sign the Jar file, and the key's associated certificate. Quite interesting how that alias works....it's a lookup into the Keystore, where each private and public key pair is identified by an alias, and a password is needed to access the private key. The keystore is generated by the Keytool.

Department of Homeland Security Says No to Web Java (Java 7, That is)

The DHS recommends users disable Java in their web browsers. Oracle has issued some security fixes.

The Recursive Mechanics of java.lang.ThreadGroup

A ThreadGroup is a set of threads. Containment - a ThreadGroup can contain other ThreadGroups (which will be like "subtrees" of the original ThreadGroup). Threads within a group can share properties e.g. setMaxPriority will set max priority in group (method is called recursively, for every ThreadGroup in the ThreadGroup). A thread may only access information about its ThreadGroup.

ThreadGroup has a final checkAccess method to determine if the currently running Thread has permission to modify the ThreadGroup. If not, a SecurityException is thrown.