Editing Java syntax (section)

=====Annotation types=====
Java has a set of predefined annotation types, but it is allowed to define new ones. An annotation type declaration is a special type of an interface declaration. They are declared in the same way as the interfaces, except the <code>interface</code> keyword is preceded by the <code>@</code> sign. All annotations are implicitly extended from <code>java.lang.annotation.Annotation</code> and cannot be extended from anything else.
<syntaxhighlight lang="java">
@interface BlockingOperations {
}
</syntaxhighlight>

Annotations may have the same declarations in the body as the common interfaces, in addition they are allowed to include enums and annotations. The main difference is that abstract method declarations must not have any parameters or throw any exceptions. Also they may have a default value, which is declared using the <code>default</code> keyword after the method name:

<syntaxhighlight lang="java">
@interface BlockingOperations {
    boolean fileSystemOperations();
    boolean networkOperations() default false;
}
</syntaxhighlight>