@Documented @Retention(RetentionPolicy.SOURCE) @Target({ElementType.FIELD}) @GroovyASTTransformationClass("org.codehaus.groovy.transform.IndexedPropertyASTTransformation") public @interface IndexedProperty
Field annotation used with properties to provide an indexed getter and setter for the property. Groovy provides nice GPath syntax support for accessing indexed properties but Java tools or frameworks may expect the JavaBean style setters and getters.
Example usage: suppose you have a class with the following properties:
will add the following methods to the class containing the properties:@IndexedPropertyFieldType[] someField@IndexedPropertyListotherField @IndexedPropertyList furtherField
FieldType getSomeField(int index) {
someField[index]
}
FieldType getOtherField(int index) {
otherField[index]
}
Object getFurtherField(int index) {
furtherField[index]
}
void setSomeField(int index, FieldType val) {
someField[index] = val
}
void setOtherField(int index, FieldType val) {
otherField[index] = val
}
void setFurtherField(int index, Object val) {
furtherField[index] = val
}
Normal Groovy visibility rules for properties apply
(i.e. no public, private or package
visibility can be specified) or you will receive a compile-time error message.
The normal Groovy property getters and setters will also be created.
More examples:
import groovy.transform.IndexedProperty
class Group {
String name
List members = []
}
class IndexedGroup {
String name
@IndexedProperty List members = []
}
def group = new Group(name: 'Groovy')
group.members[0] = 'mrhaki'
group.members[1] = 'Hubert'
assert 2 == group.members.size()
assert ['mrhaki', 'Hubert'] == group.members
try {
group.setMembers(0, 'hubert') // Not index property
} catch (MissingMethodException e) {
assert e
}
def indexedGroup = new IndexedGroup(name: 'Grails')
indexedGroup.members[0] = 'mrhaki'
indexedGroup.setMembers 1, 'Hubert'
assert 2 == indexedGroup.members.size()
assert 'mrhaki' == indexedGroup.getMembers(0)
assert 'Hubert' == indexedGroup.members[1]