net.sf.jrtps.udds

Annotation Type Key

@Documented
 @Retention(value=RUNTIME)
 @Target(value=FIELD)
 @Inherited
public @interface Key

This annotation provides means to tag fields as being part of a RTPS(DDS) key. A key uniquely identifies an instance of an Object in domain/topic.
A default index is set to 0, which allows fields to be annotated with a simple Key annotation:

 public class HelloMessage {
     private @Key
     int id;
     private String message;
 }
 

An example with multiple Key elements:

 public class HelloMessage {
     private @Key(index = 0)
     int id;
     private @Key(index = 1)
     long foreignId;
     private String message;
 }
 

Author:

mcr70

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
int	index Get the index of the key.

Element Detail

index

public abstract int index

Get the index of the key. A key may be composed of multiple fields. This annotation method provides means to set those fields in a known order. Key fields are ordered according to their index.

It is an error to provide two fields with same index.

Returns:

index of the key

Default:

0