This write strategy is the default for transferring objects through an RMI connection.
After examining the object for non customizable aspects of the transferring (see RMIObjectWriteHandler documentation), the following rules apply to transferring objects:
In the following, the target type is the receiver type of the transferred object during transfer.
E.g. if the method is
void method(Number n) and the parameter is an instance of Integer, then
the target type is Number, and the object type is Integer.
- If the target type is an array, then the object is transferred as an array, and its elements are transferred with
a target type of the component type of the target type.
void method(Number n)with parameter Integer
, the elements will be transferred with target type of Number.
- If the object is an array, then it will be transferred as an array, and its elements are transferred with a
target type of the component type of the array type.
void method(Object n)with parameter Integer
, the elements will be transferred with target type of Integer.
- If the object is an Enum instance, then it will be transferred by name. See EnumRMIObjectWriteHandler.
- If the object is a ClassLoader instance, then it will be transferred by name using the specified classloader resolver settings.
- If the object is a Class, Method, Constructor or Field instance, then it will be transferred by their enclosing reflectional information, and will be looked up on the other endpoint.
- If the target type is an interface, or
RemoteProxyObjectthen it will be written as a remote object. See RemoteRMIObjectWriteHandler.
void method(Runnable run)with parameter of a lambda
() -> System.out.println("hello"), will be transferred as a remote object. Any calls on the received Runnable will result in printing
"hello"to the stdout on the client side.
- Regardless of target type, the object will be tried to be written as an Externalizable object. This will
only happen if the given object is an instance of Externalizable.
The object is not written using ObjectOutputStream, but the RMIObjectOutput interface will be used to call Externalizable.writeExternal(
ObjectOutput). Any ObjectOutput.writeObject( Object)calls will use the default object writing strategy, and Object target type.
- If the object is an instace of Throwable, it will be attempted to be transferred as a serializable object. See SerializeRMIObjectWriteHandler. (Since saker.rmi 0.8.1)
- As a fallback mechanism, the RMI runtime will write the given object as a remote to the other side. This means
that if the actual target type can not accept an interface, then the RMI request will likely fail. This can be
considered an undefined behavior and the user should attempt to properly choose the interfaces and instances for RMI
This fallback mechanism can be used as well to transfer Externalizable instances and some remote object with it.
Creates a new instance.
Indicates whether some other object is "equal to" this one.
Gets the kind of this object write handler.
Returns a hash code value for the object.
Returns a string representation of the object.
equals method implements an equivalence relation on non-null object references:
- It is reflexive: for any non-null reference value
- It is symmetric: for any non-null reference values
trueif and only if
- It is transitive: for any non-null reference values
- It is consistent: for any non-null reference values
y, multiple invocations of
trueor consistently return
false, provided no information used in
equalscomparisons on the objects is modified.
- For any non-null reference value
equals method for class
Object implements the most discriminating possible equivalence
relation on objects; that is, for any non-null reference values
y, this method returns
true if and only if
y refer to the same object (
x == y has the value
Note that it is generally necessary to override the
hashCode method whenever this method is overridden,
so as to maintain the general contract for the
hashCode method, which states that equal objects must have
equal hash codes.
trueif this object is the same as the obj argument;
The general contract of
- Whenever it is invoked on the same object more than once during an execution of a Java application, the
hashCodemethod must consistently return the same integer, provided no information used in
equalscomparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
- If two objects are equal according to the
equals(Object)method, then calling the
hashCodemethod on each of the two objects must produce the same integer result.
- It is not required that if two objects are unequal according to the
Object)method, then calling the
hashCodemethod on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by class
Object does return distinct
integers for distinct objects. (This is typically implemented by converting the internal address of the object
into an integer, but this implementation technique is not required by the Java™ programming language.)
toStringmethod returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
toString method for class
Object returns a string consisting of the name of the class of
which the object is an instance, the at-sign character `
@', and the unsigned hexadecimal representation
of the hash code of the object. In other words, this method returns a string equal to the value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())