Blocks and Statements - The Java Language Specification - page 412

is given by the following translation to a basic try -with-resources statement (§ 14.20.3.1 )
nested inside a try - catch or try - finally or try - catch - finally statement:
try {
try ResourceSpecification
Block
}
Catches opt
Finally opt
The effect of the translation is to put the ResourceSpecification “inside” the try statement.
This allows a catch clause of an extended try -with-resources statement to catch an exception
due to the automatic initialization or closing of any resource.
Furthermore, all resources will have been closed (or attempted to be closed) by the time the
finally block is executed, in keeping with the intent of the finally keyword.
14.21. Unreachable Statements
It is a compile-time error if a statement cannot be executed because it is unreachable .
This section is devoted to a precise explanation of the word “reachable.” The idea is
that there must be some possible execution path from the beginning of the construct-
or, method, instance initializer, or static initializer that contains the statement to the
statement itself. The analysis takes into account the structure of statements. Except for
the special treatment of while , do , and for statements whose condition expression has
the constant value true , the values of expressions are not taken into account in the flow
analysis.
For example, a Java compiler will accept the code:
{
int n = 5;
while (n > 7) k = 2;
}
even though the value of n is known at compile time and in principle it can be known
at compile time that the assignment to k can never be executed.
The rules in this section define two technical terms:
• whether a statement is reachable
• whether a statement can complete normally
The definitions here allow a statement to complete normally only if it is reachable.