Question

I’ve never seen this before – what is it called? This is a class level variable, at the beginning of the file.

Just to be clear, I’m referring to the static {} after the variable.

private static final UriMatcher URI_MATCHER;
    static {
        URI_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
        URI_MATCHER.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, SEARCH);
        URI_MATCHER.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", SEARCH);
        URI_MATCHER.addURI(AUTHORITY, "books", BOOKS);
        URI_MATCHER.addURI(AUTHORITY, "books/#", BOOK_ID);
    }

Answer 1

It’s an static initialization block. It can be declared anywhere inside a class (but outside a method), but by convention it’s usually written right after the static variable that’s being initialized. It’s specified in the Java Language Specification, section §8.7.

As the name implies, it’s normally used for initializing the state of static attributes in the class at class-loading time. From the Java tutorial:

A static initialization block is a normal block of code enclosed in braces, { }, and preceded by the static keyword (…) A class can have any number of static initialization blocks, and they can appear anywhere in the class body. The runtime system guarantees that static initialization blocks are called in the order that they appear in the source code.