Package groovy.transform

Annotation Type ExternalizeMethods

@Documented @Retention(RUNTIME) @Target(TYPE) public @interface ExternalizeMethods
Class annotation used to assist in the creation of Externalizable classes. The @ExternalizeMethods annotation instructs the compiler to execute an AST transformation which adds writeExternal() and readExternal() methods to a class and adds Externalizable to the interfaces which the class implements. The writeExternal() method writes each property (and optionally field) of the class while the readExternal() method will read each one back in the same order. Properties or fields marked as transient are ignored. This annotation is typically used in conjunction with the @ExternalizeVerifier annotation but most usually not directly but rather via @AutoExternalizable which is a shortcut for both annotations.

Example usage: 

 import groovy.transform.*
 @ExternalizeMethods
 class Person {
   String first, last
   List favItems
   Date since
 }
Which will create a class of the following form: 
 class Person implements Externalizable {
   ...
   public void writeExternal(ObjectOutput out) throws IOException {
     out.writeObject(first)
     out.writeObject(last)
     out.writeObject(favItems)
     out.writeObject(since)
   }

   public void readExternal(ObjectInput oin) {
     first = (String) oin.readObject()
     last = (String) oin.readObject()
     favItems = (List) oin.readObject()
     since = (Date) oin.readObject()
   }
   ...
 }
Since:
1.8.0

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    String[]
    excludes
    Comma separated list of property names to exclude from externalizing.
    boolean
    includeFields
    Include fields as well as properties when externalizing.

  • Element Details

    • excludes

      String[] excludes
      Comma separated list of property names to exclude from externalizing. For convenience, a String with comma separated names can be used in addition to an array (using Groovy's literal list notation) of String values.
      Default:
      {}

    • includeFields

      boolean includeFields
      Include fields as well as properties when externalizing.
      Default:
      false