In Java terminology, a serializable object typically refers to an object that implements the java.io.Serializable
interface and therefore supports serialization to and from a byte stream. All Java classes generated from Slice definitions implement the java.io.Serializable
interface.
In addition to serializing Slice types, applications may also need to incorporate foreign types into their Slice definitions. Ice allows you to pass Java serializable objects directly as operation parameters or as fields of another data type. For example:
["java:serializable:SomePackage.JavaClass"] sequence<byte> JavaObj; struct MyStruct { int i; JavaObj o; }; interface Example { void op(JavaObj inObj, MyStruct s, out JavaObj outObj); };
The generated code for MyStruct
contains a member i
of type int
and a member o
of type SomePackage.JavaClass
:
public final class MyStruct implements java.lang.Cloneable { public int i; public SomePackage.JavaClass o; // ... }
Similarly, the signature for op
has parameters of type JavaClass
and MyStruct
for the in-parameters, and Ice.Holder<SomePackage.JavaClass>
for the out-parameter. (Out-parameters are always passed as Ice.Holder<class>
.)
void op(SomePackage.JavaClass inObj, MyStruct s, Ice.Holder<SomePackage.JavaClass> outObj);
Of course, your client and server code must have an implementation of Java
Class
that derives from java.io.Serializable
:
package SomePackage; public class JavaClass implements java.io.Serializable { // ... }
You can implement this class in any way you see fit — the Ice run time does not place any other requirements on the implementation.