说明和注释类型 : 注释类型 « 语言基础 « Java 教程

Annotations are notes in Java programs to instruct the Java compiler to do something. Java provides three standard annotations and four standard meta-annotations.

1. An annotation type is a special interface type.
2. An annotation is an instance of an annotation type.
3. An annotation type has a name and members.
4. The information contained in an annotation takes the form of key/value pairs.
5. There can be zero or multiple pairs and each key has a specific type.
6. It can be a String, int, or other Java types.
7. Annotation types with no key/value pairs are called marker annotation types.
8. Those with one key/value pair are referred to single-value annotation types.

1. There are three annotation types in Java 5: Deprecated, Override, and Suppress Warnings.
2. There are four other annotation types that are part of the java.lang.annotation package: Documented, Inherited, Retention, and Target.
3. These four annotation types are used to annotate annotations,