Question

I am trying to compile a software using javac. The problem is i removed open-jdk using yum remove and downloaded sun jdk and installed it in the /usr/java folder.

I don’t know how to figure out if the current jvm is openjdk running or sunjdk.

I removed the java and javac files from the /usr/bin folder and made the PATH variable contain the new path in /usr/java/jdk1.6-0/bin.

I still see the java file in bin folder everytime I restart the system.

Could some one help me with this?

Also if this is gonna be helpful, I am trying to compile a software and it gives the following warnings:

List is a raw type. References to
generic type List should be
parameterized

I think it is because of open-jdk. I’m not able to figure out how to completely remove open-jdk.

Thanks

Answer 1

1. From the perspective of application behaviour, there should be no perceptible difference between OpenJDK and the equivalent Oracle JDK. The differences are down in the low levels of the JVM; e.g. performance improvements in the JIT compiler and the garbage collectors.

2. If you need to tell which version you are actually running, use java -version, or (in a running application) look at the properties in the object System.getProperties(). (The javadoc explains what standard properties to expect.)

3. The message about raw types is nothing to do with whether your system is OpenJDK or Oracle JDK. You will get similar warning messages with all Java 5 / 6 / 7 compilers … including compilers from IBM and other places.

   The actual problem is in the code that you are compiling. You can safely ignore the warning in the short term … or if the code has to remain compilable by /runnable on pre-Java 5 JVMs.