What are static code blocks for?

Question

I want to ask what javap shows besides the public fields and methods of the classes passed to it.

I was reviewing a class file having only a static variable. As expected, javap shows the static variable and class constructor as output but it also shows something like:

static {};

What does this line mean?

It is a [static initializer](http://docs.oracle.com/javase/specs/jls/se7/html/jls-8.html#jls-8.7). — johnchen902, Jul 29 '13 at 13:36

score 5 · Accepted Answer · answered Aug 12 '13 at 17:35

5

static code block initializes the static variables in the program. it gets executed when the class is initiated, even before constructor call.

answered Aug 12 '13 at 17:35

Prasad Kharkar · Answer 2 · 2013-07-29T14:24:37.183

4

This is a static block which is used for initializing values
This block gets executed when the class is initialized
The static initializer block is executed whenver the class is initialized and the order of execution is according to their appearance in program.

edited Jul 29 '13 at 14:24

answered Jul 29 '13 at 13:12

Prasad Kharkar

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*"This block gets executed when the class is loaded into JVM"*. No, it is executed when the class is *initialized*. – johnchen902 Jul 29 '13 at 13:40
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It is executed each time a class is initialized (which might be more than once with multiple class loaders) – Peter Lawrey Jul 29 '13 at 13:41

score 0 · Answer 3 · answered Jul 29 '13 at 13:15

0

javap -private -verbose class will show you the constant pool and the details of the method bytecode.

answered Jul 29 '13 at 13:15

Raji

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What are static code blocks for?

3 Answers3