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20131126

test class demonstrating how java 7's JVM processes class initialization and instantiation

Just wrote a java class to demonstrate JVM 7's class initialization processing order

click the link above to go to the source code.

i created a java class with a "main" method, some static variables and some normal (non-static) instance variables, then ran this file with debug breakpoints on all lines of code to find the processing order and here's what i found:

* access modifiers for variables and methods (private, public, protected, etc) don't seem to affect processing order, ALTHOUGH the "main" method must have the "public" modifier

* standard getter and setter methods for variables don't get processed, i.e. debugger never stops on their breakpoints

* "static final" variables don't get processed by the JVM during initialization or instantiation of the class, i.e. debugger never stops on their breakpoints


processing order:
1. static variables and static initialization blocks, in textual order of appearance
2. "main" method:
    2.1 begin executing any logic encountered
        2.1.1 if a call to instantiate the containing class is made (i.e. "new JVMClassInitializationProcessingOrderTest()"), temporarily pause execution of "main" method logic
            2.1.1.1 initialize (non-static) instance variables and (non-static) initialization blocks, in textual order of appearance
            2.1.1.2 process the class' constructor
            2.1.1.3 resume execution of the remaining logic in the "main" method

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