Typically, APARs are not cumulative, because each APAR corresponds to fixes for a subset of Java6_64 filesets. Different APARs can have different subsets of Java6_64 filesets. However, the individual Java6_64 filesets will contain cumulative fixes. Check the version.release.modification.fix (vrmf) number to compare fileset levels. For example, the fixes in fileset 6.0.0.75 contain or supercede the fixes delivered in fileset 6.0.0.50 and below.
How do I know if I have installed the latest code?
There are different ways to determine the level of code on your system:
You can check and compare the build date of your Java installation by using the command: /usr/java6_64/jre/bin/java -fullversion
You can check to see if a particular APAR is installed on your system by using the command: instfix -ivk APAR_NUMBER
You can check the Java6_64 filesets installed on your system by using the command: lslpp -L | grep Java6_64. The list produced by this command might show filesets that are optional, such as java6_64.samples or java6_64.source. The java6_64.sdk fileset is the only fileset you need.