java.rmi: public final class: MarshalledObject

java.rmi
public final class: MarshalledObject [javadoc | source]

java.lang.Object
   java.rmi.MarshalledObject

All Implemented Interfaces:
java$io$Serializable

A MarshalledObject contains a byte stream with the serialized representation of an object given to its constructor. The get method returns a new copy of the original object, as deserialized from the contained byte stream. The contained object is serialized and deserialized with the same serialization semantics used for marshaling and unmarshaling parameters and return values of RMI calls: When the serialized form is created:

classes are annotated with a codebase URL from where the class can be loaded (if available), and
any remote object in the MarshalledObject is represented by a serialized instance of its stub.

When copy of the object is retrieved (via the get method), if the class is not available locally, it will be loaded from the appropriate location (specified the URL annotated with the class descriptor when the class was serialized.

MarshalledObject facilitates passing objects in RMI calls that are not automatically deserialized immediately by the remote peer.

Parameters:

- the type of the object contained in this MarshalledObject

author: Ann - Wollrath

author: Peter - Jones

since: 1.2 -

Constructor:

Constructor:
public MarshalledObject(T obj) throws IOException { if (obj == null) { hash = 13; return; } ByteArrayOutputStream bout = new ByteArrayOutputStream(); ByteArrayOutputStream lout = new ByteArrayOutputStream(); MarshalledObjectOutputStream out = new MarshalledObjectOutputStream(bout, lout); out.writeObject(obj); out.flush(); objBytes = bout.toByteArray(); // locBytes is null if no annotations locBytes = (out.hadAnnotations() ? lout.toByteArray() : null); /* * Calculate hash from the marshalled representation of object * so the hashcode will be comparable when sent between VMs. / int h = 0; for (int i = 0; i < objBytes.length; i++) { h = 31 h + objBytes[i]; } hash = h; } Creates a new `MarshalledObject` that contains the serialized representation of the current state of the supplied object. The object is serialized with the semantics used for marshaling parameters for RMI calls. Parameters: `obj` - the object to be serialized (must be serializable) Throws: `IOException` - if an `IOException` occurs; an `IOException` may occur if `obj` is not serializable. exception: `IOException` - if an `IOException` occurs; an `IOException` may occur if `obj` is not serializable. since: `1.2` -

 public MarshalledObject(T obj) throws IOException {
        if (obj == null) {
            hash = 13;
            return;
        }
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        ByteArrayOutputStream lout = new ByteArrayOutputStream();
        MarshalledObjectOutputStream out =
            new MarshalledObjectOutputStream(bout, lout);
        out.writeObject(obj);
        out.flush();
        objBytes = bout.toByteArray();
        // locBytes is null if no annotations
        locBytes = (out.hadAnnotations() ? lout.toByteArray() : null);
        /*
         * Calculate hash from the marshalled representation of object
         * so the hashcode will be comparable when sent between VMs.
         */
        int h = 0;
        for (int i = 0; i <  objBytes.length; i++) {
            h = 31 * h + objBytes[i];
        }
        hash = h;
}

MarshalledObject

Parameters:

obj - the object to be serialized (must be serializable)

Throws:

IOException - if an IOException occurs; an IOException may occur if obj is not serializable.

exception: IOException - if an IOException occurs; an IOException may occur if obj is not serializable.

since: 1.2 -

Method from java.rmi.MarshalledObject Summary:
equals, get, hashCode

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from java.rmi.MarshalledObject Detail:
public boolean equals(Object obj) { if (obj == this) return true; if (obj != null && obj instanceof MarshalledObject) { MarshalledObject other = (MarshalledObject) obj; // if either is a ref to null, both must be if (objBytes == null \|\| other.objBytes == null) return objBytes == other.objBytes; // quick, easy test if (objBytes.length != other.objBytes.length) return false; //!! There is talk about adding an array comparision method //!! at 1.2 -- if so, this should be rewritten. -arnold for (int i = 0; i < objBytes.length; ++i) { if (objBytes[i] != other.objBytes[i]) return false; } return true; } else { return false; } } Compares this `MarshalledObject` to another object. Returns true if and only if the argument refers to a `MarshalledObject` that contains exactly the same serialized representation of an object as this one does. The comparison ignores any class codebase annotation, meaning that two objects are equivalent if they have the same serialized representation except for the codebase of each class in the serialized representation.
public T get() throws IOException, ClassNotFoundException { if (objBytes == null) // must have been a null object return null; ByteArrayInputStream bin = new ByteArrayInputStream(objBytes); // locBytes is null if no annotations ByteArrayInputStream lin = (locBytes == null ? null : new ByteArrayInputStream(locBytes)); MarshalledObjectInputStream in = new MarshalledObjectInputStream(bin, lin); T obj = (T) in.readObject(); in.close(); return obj; } Returns a new copy of the contained marshalledobject. The internal representation is deserialized with the semantics used for unmarshaling paramters for RMI calls.
public int hashCode() { return hash; } Return a hash code for this `MarshalledObject`.

Method from java.rmi.MarshalledObject Detail:

 public boolean equals(Object obj) {
        if (obj == this)
            return true;
        if (obj != null && obj instanceof MarshalledObject) {
            MarshalledObject other = (MarshalledObject) obj;
            // if either is a ref to null, both must be
            if (objBytes == null || other.objBytes == null)
                return objBytes == other.objBytes;
            // quick, easy test
            if (objBytes.length != other.objBytes.length)
                return false;
            //!! There is talk about adding an array comparision method
            //!! at 1.2 -- if so, this should be rewritten.  -arnold
            for (int i = 0; i <  objBytes.length; ++i) {
                if (objBytes[i] != other.objBytes[i])
                    return false;
            }
            return true;
        } else {
            return false;
        }
}

MarshalledObject

except

 public T get() throws IOException, ClassNotFoundException {
        if (objBytes == null)   // must have been a null object
            return null;
        ByteArrayInputStream bin = new ByteArrayInputStream(objBytes);
        // locBytes is null if no annotations
        ByteArrayInputStream lin =
            (locBytes == null ? null : new ByteArrayInputStream(locBytes));
        MarshalledObjectInputStream in =
            new MarshalledObjectInputStream(bin, lin);
        T obj = (T) in.readObject();
        in.close();
        return obj;
}

Returns a new copy of the contained marshalledobject. The internal representation is deserialized with the semantics used for unmarshaling paramters for RMI calls.

 public int hashCode() {
        return hash;
}

MarshalledObject