java.lang.annotation

1. Type Annotation with Retention Policy

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value();
}

@MyAnnotation("Example Value")
public class MyClass {
    // ...
}

2. Method Parameter Annotation

public void myMethod(@MyAnnotation String parameter) {
    // ...
}

3. Method Return Value Annotation

@MyAnnotation
public String myMethod() {
    // ...
    return "Example Value";
}

4. Field Annotation

public class MyClass {
    @MyAnnotation
    private String myField;
    // ...
}

5. Type Annotation with Multiple Values

@MyAnnotation({ "Value 1", "Value 2" })
public class MyClass {
    // ...
}

6. Type Annotation with Default Value

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value() default "Default Value";
}

@MyAnnotation
public class MyClass {
    // ...
}

7. Type Annotation with Alias

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String name() alias for "value";
}

@MyAnnotation(name = "Example Value")
public class MyClass {
    // ...
}

8. Method Parameter Annotation with Nested Annotation

@MyAnnotationNested(value = "Nested Value")
public void myMethod(@MyAnnotation String parameter) {
    // ...
}

9. Method Return Value Annotation with Nested Annotation

@MyAnnotationNested(value = "Nested Value")
public String myMethod() {
    // ...
    return "Example Value";
}

10. Field Annotation with Nested Annotation

public class MyClass {
    @MyAnnotationNested(value = "Nested Value")
    private String myField;
    // ...
}

11. Type Annotation with Retention Policy and Target

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.METHOD })
public @interface MyAnnotation {
    String value();
}

12. Type Annotation with Inheritance

@Inherited
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value();
}

public class Superclass {
    @MyAnnotation("Superclass Value")
    // ...
}

public class Subclass extends Superclass {
    // ...
}

13. Type Annotation with Documentation

@Documented
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value();
}

14. Type Annotation for JUnit Testing

import org.junit.jupiter.api.Test;

@MyAnnotation
@Test
public void myTest() {
    // ...
}

15. Type Annotation for Database Mapping

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
@MyAnnotation
public class MyEntity {
    @Id
    private Long id;
    // ...
}

16. Type Annotation for Dependency Injection

import javax.inject.Qualifier;

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    String value();
}

17. Type Annotation for Logging

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.METHOD, ElementType.TYPE })
public @interface Loggable {
    Level value() default Level.INFO;
}

18. Type Annotation for Configuration

import org.springframework.context.annotation.Configuration;

@Configuration
@MyAnnotation
public class MyConfiguration {
    // ...
}

19. Type Annotation for Metrics Collection

import io.micrometer.core.annotation.Timed;

@Timed
public void myMethod() {
    // ...
}

20. Type Annotation for Tracing

import io.opentelemetry.api.trace.SpanKind;

@SpanKind(SpanKind.SERVER)
public void myMethod() {
    // ...
}

21. Type Annotation for Security

import javax.annotation.security.RolesAllowed;

@RolesAllowed("ADMIN")
public void myMethod() {
    // ...
}

22. Type Annotation for XML Serialization

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class MyObject {
    // ...
}

23. Type Annotation for JSON Serialization

import com.fasterxml.jackson.annotation.JsonProperty;

public class MyObject {
    @JsonProperty("my_property")
    private String myProperty;
    // ...
}

24. Type Annotation for Swagger Documentation

import io.swagger.annotations.ApiOperation;

@ApiOperation("My Operation")
public void myMethod() {
    // ...
}

25. Type Annotation for REST API

import javax.ws.rs.Path;
import javax.ws.rs.GET;

@Path("/my-resource")
public class MyResource {
    @GET
    public String myMethod() {
        // ...
        return "Example Response";
    }
}

26. Type Annotation for Event Handling

import org.springframework.context.event.EventListener;

public class MyEventListener {
    @EventListener
    public void handleMyEvent(MyEvent event) {
        // ...
    }
}

27. Type Annotation for Task Scheduling

import org.springframework.scheduling.annotation.Scheduled;

public class MyTask {
    @Scheduled(cron = "0 * * * * *")
    public void myScheduledTask() {
        // ...
    }
}

28. Type Annotation for Aspect-Oriented Programming

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

@Aspect
public class MyAspect {
    @Before("execution(* myMethod())")
    public void myAdvice() {
        // ...
    }
}

29. Type Annotation for Code Coverage

import org.jacoco.agent.rt.EnableJaCoCo;

@EnableJaCoCo
public class MyTestClass {
    // ...
}

30. Type Annotation for SonarQube Code Quality

import org.sonar.api.rule.RuleKey;
import org.sonar.api.rule.Rule;
import org.sonar.api.rule.RuleCategory;

@Rule(key = RuleKey.of("my-rule"))
@RuleCategory(RuleCategory.BUG)
public class MySonarQubeRule {
    // ...
}

31. Type Annotation for Kotlin Coroutines

import kotlinx.coroutines.InternalCoroutinesApi
import kotlinx.coroutines.FlowPreview
import kotlinx.coroutines.InternalCoroutinesApi
import kotlinx.coroutines.flow.Flow

@InternalCoroutinesApi
@FlowPreview
fun myFlow(): Flow<Int> {
    // ...
}

32. Type Annotation for Java 9+

import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

@MyAnnotation("Value 1")
@MyAnnotation("Value 2")
public class MyClass {
    // ...
}

33. Type Annotation for Java 10+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
public @interface MyAnnotation {
    String value();
}

34. Type Annotation for Java 11+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

35. Type Annotation for Java 12+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

36. Type Annotation for Java 13+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

37. Type Annotation for Java 14+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

38. Type Annotation for Java 15+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

39. Type Annotation for Java 16+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

40. Type Annotation for Java 17+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

41. Type Annotation for Java 18+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

42. Type Annotation for Java 19+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

43. Type Annotation for Java 20+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

44. Type Annotation for Java 21+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

45. Type Annotation for Java 22+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

46. Type Annotation for Java 23+

import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
import java.lang.annotation.Repeatable;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER })
@Repeatable(MyAnnotations.class)
public @interface MyAnnotation {
    String value();
}

**47. Type Annotation for Java

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