That way, the generated classes will be available in IntelliJ Idea. In Eclipse exists also an additional configuration section under Java Compiler. There you can configure all kinds of aspects of annotation processing. Just check the "Enable annotation processing" option, configure the directory for the generated sources and finally add the Hibernate Static Metamodel Generator and JPA 2 jar files to the factory path.
If set to true additional trace information will be outputted by the processor. Specifying this option a persitence. Allows to specify additional entity mapping files. The specified value for this option is a comma separated string of mapping file names. Possible values are true or false. If set to true the annotation processor tries to determine whether any of the xml files has changed between invocations and if unchanged skips the xml parsing.
This feature is experimental and contains the risk of wrong results in some cases of mixed mode configurations. To determine wether a file has been modified a temporary file Hibernate-Static-Metamodel-Generator.
This file gets created in the java. If set to true the processor will ignore orm. If set to true the processor will add the Generated to the generated Java source file. Adding this annotation using JDK 5 will cause a compilation error. In this case set the flag to false. The default for this option is true. If set to true the generation date of the metamodel class will be inserted in the date parameter of the Generated annotation.
As you can tell, the generate metamodel class is a Java class. This is not a problem since Kotlin is fully interoperable with Java. Since the Criteria API provides overloaded methods that accept String references as well as Attribute interface implementations, we can use the generated metamodel classes in the same way we would use the String references to attributes.
And this is what it looks like without using the metamodel class:. The main difference lies in how the entity attribute name is retrieved. If that attribute changes, in the first example we will get a compile-time error, while in the second one a more dangerous runtime-error will be thrown. Using metamodel classes makes the code cleaner, easier, and more robust. JPA Metamodel provides a type-safe way to define criteria queries.
This makes future refactorings far easier than referencing the attributes via strings, causing code to be more robust to changes. Many different metamodel generator tools can be used with an annotation processor to generate the metamodel classes at build-time. This means that changes in entity attributes will automatically be reflected in the metamodel classes, avoiding runtime-errors.
Thanks for reading! Developing with JavaServer Faces Technology. Composite Components: Advanced Topics and Example. Configuring JavaServer Faces Applications. Uploading Files with Java Servlet Technology. Internationalizing and Localizing Web Applications. Using the Embedded Enterprise Bean Container. Expression Methods in the CriteriaBuilder Interface. Getting Started Securing Web Applications.
Getting Started Securing Enterprise Applications. The Metamodel API is used to create a metamodel of the managed entities in a particular persistence unit. For each entity class in a particular package, a metamodel class is created with a trailing underscore and with attributes that correspond to the persistent fields or properties of the entity class. The following entity class, com. Pet , has four persistent fields: id , name , color , and owners :.
It has no influence on the Maven build itself. StefanHeimberg StefanHeimberg 1, 12 12 silver badges 22 22 bronze badges.
I had no error but this did the trick, thank you. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Explaining the semiconductor shortage, and how it might end. Does ES6 make JavaScript frameworks obsolete?
Featured on Meta. Now live: A fully responsive profile. Visit chat.
0コメント