CLASSES

Static Initializers

8.5

A different compile time error now occurs, because the body of the method

move

cannot throw a checked exception, namely

BadPointException

, that does not

appear in the

throws

 clause for

move

.

8.5   Static Initializers

Any

static initializers

declared in a class are executed when the class is initialized

and, together with any field initializers ( 8.3.2) for class variables, may be used to

initialize the class variables of the class ( 12.4).

StaticInitializer:

static

Block

It is a compile time error for a static initializer to be able to complete abruptly

( 14.1,  15.5) with a checked exception ( 11.2).

The static initializers and class variable initializers are executed in textual

order and may not refer to class variables declared in the class whose declarations

appear textually after the use, even though these class variables are in scope. This

restriction is designed to catch, at compile time, circular or otherwise malformed

initializations. Thus, both:

class Z {

static int i = j + 2;

static int j = 4;

}

and:

class Z {

static { i = j + 2; }

static int i, j;

static { j = 4; }

}

result in compile time errors.

Accesses to class variables by methods are not checked in this way, so:

class Z {

static int peek() { return j; }

static int i = peek();

static int j = 1;

}

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