Transformer
object is used to convert strings to and from object instances. This is used during the serialization and deserialization process to transform types from the Java class libraries, as well as other types which do not contain XML schema annotations. Typically this will be used to transform primitive types to and from strings, such as int
values. @Element private String[] value; For example taking the above value the array of strings needs to be converted in to a single string value that can be inserted in to the element in such a way that in can be read later. In this case the serialized value of the string array would be as follows. <value>one, two, three</value> Here each non-null string is inserted in to a comma separated list of values, which can later be deserialized. Just to note the above array could be annotated with ElementList
just as easily, in which case each entry would have its own element. The choice of which annotation to use is up to the developer. A more obvious benefit to transformations like this can be seen for values annotated with the Attribute
annotation.