Annotation In Java

What is annotation in Java with example?

Annotation in java is a kind of a tag that represents the metadata or information attached with class, interface, methods, or fields to show some additional information that Java compiler and JVM can use.

Built-In Java Annotations used in Java code

• @Override
• @SuppressWarnings
• @Deprecated

Built-In Java Annotations used in other annotations (used to create custom annotations)

• @Target
• @Retention
• @Inherited
• @Documented

What does annotate mean in Java?

What is a Java annotation type?

Types of Java Annotations

There are five types of Java Annotations which are:

• Marker Annotations
• Single Value Annotations
• Multi-Value Annotation
• Full Annotations
• Type Annotation
• Repeating Annotation

What is annotation in Java and how it works?

@Retention annotation is used to specify to what is the level annotation and where it will be available.There are 3 type of RetentionPolicy like SOURCE, CLASS, RUNTIME

• RetentionPolicy.SOURCE : This is refers to the source code, It will not be available in the compiled class.
• RetentionPolicy.CLASS : This is refers to the .class file, available to java compiler but not to JVM . It is included in the class file.
• RetentionPolicy.RUNTIME : This is refers to the runtime, available to  java compiler and JVM .