This is most likely because you are switching between Java 1.5 and Java 1.6. In 1.5 you couldn’t mark interface implementations with @Override, but you can in 1.6. A quick Google search turned up this good explanation of the difference in this annotation between the two versions: http://www.techienuggets.com/CommentDetail?tx=38155 Semantics of @Override is different in JDK … Read more
Add an artifact containing the classes you need to the classpath. It appears that the javax.annotation API is what you need. See https://mvnrepository.com/artifact/javax.annotation/javax.annotation-api/1.3.2 for details. You can add the following dependency to your project as any other and it should be present: <!– https://mvnrepository.com/artifact/javax.annotation/javax.annotation-api –> <dependency> <groupId>javax.annotation</groupId> <artifactId>javax.annotation-api</artifactId> <version>1.3.2</version> </dependency> Remember to remove the compiler … Read more
To create an instance you need to create a class that implements: java.lang.annotation.Annotation and the annotation you want to “simulate” For example: public class MySettings implements Annotation, Settings But you need to pay special attention to the correct implementation of equals and hashCode according to the Annotation interface. http://download.oracle.com/javase/1.5.0/docs/api/java/lang/annotation/Annotation.html If you do not want to … Read more
bnd tool (and maven-bundle-plugin) makes use of package annotations. Putting @Version and @Export annotation in package-info.java allows it to generate OSGi metadata. javadoc uses package annotations. JAXB uses package-level annotations, for example, to specify mapping of a Java type to XML Schema type package-wide. Package annotations are also used in JBoss’s xml binding. Struts 2 … Read more
I think it is possible, but it requires lots of additions to language spec, which is not justified. First, for you enum example, you could use Class<? extends Enum<?>> options. There is another problem in Class<? extends Enum> options: since Enum.class is a Class<Enum> which is a Class<? extends Enum>, it’s legal to options=Enum.class That … Read more
As Forum has many topics, and a topic belongs to one and only Forum, you probably want to go with a Forum type attribute annotated with @ManyToOne: @ManyToOne @JoinColumn(name = “forumId”) private Forum forum; See more: ManyToOne and JPA mapping
Try this (java reflection): String field = En.AAA.name(); En.class.getField(field).getAnnotations(); It should get you the annotations from AAA. EDIT: As the author supposed: en1.getClass().getField(((Enum)en1).name()).getAnnotations(); Works for him 🙂
I’ve never used it in practice but what you get is, that you can use classes as replacement for your annotations. Let’s create an artificial example. Say we have an documentation generator. It reads a @Docu annotation from given classes and prints the description attribute. Like this: import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; … Read more
The problem is that GenericTraversableTemplate is used twice: once for mutable collections (where its type parameter should be invariant), and once for immutable collections (where covariance is invariably king). GenericTraversableTemplate’s typechecks assuming either covariance or invariance for the A type parameter. However, when we inherit it in a mutable trait, we have to pick invariance. … Read more
Usually this is done using the process called classpath scanning. In general class loaders do not allow for scanning through all the classes on the classpath. But usually the only used class loader is UrlClassLoader from which we can retrieve the list of directories and jar files (see getURLs) and open them one by one … Read more