Difference between the static initializer block and regular static initialization

Question

As the title says, what exactly is the difference between

public static String myString = \"Hello World!\";

and

public stat         


        

Answer 1

The static {...} block gives you the opportunity to do more than you would be able to do in the field declaration.

For example, you can fill in some details of a map:

private static final Map data = new HashMap();

static {
    data.put("A", "Hello");
    data.put("B", "There");
    data.put("C", "You");
}

Sometimes you may also need to get data (from a file, database, etc) before you can instantiate:

public class Foo {
    private static final Person person;

    static {
        InputStream personData = Foo.class.getResourceAsStream("something.txt");
        person = new Person(personData);
    }
    ...
}