org.jinterop.dcom.core.JIUnion Maven / Gradle / Ivy
/** j-Interop (Pure Java implementation of DCOM protocol)
* Copyright (C) 2006 Vikram Roopchand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3.0 of the License, or (at your option) any later version.
*
* Though a sincere effort has been made to deliver a professional,
* quality product,the library itself is distributed WITHOUT ANY WARRANTY;
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
*/
package org.jinterop.dcom.core;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import ndr.NetworkDataRepresentation;
import org.jinterop.dcom.common.JIErrorCodes;
import org.jinterop.dcom.common.JIException;
import org.jinterop.dcom.common.JIRuntimeException;
import org.jinterop.dcom.common.JISystem;
/**
* < p>
* This class represents the Union data type. Its usage is dictated
* by the discriminant which acts as a "switch" to select the correct member to
* be serialized\deserialzed.
*
*
* Sample Usage :-
*
*
*
* JIUnion forTypeDesc = new JIUnion(Short.class);
* JIPointer ptrToTypeDesc = new JIPointer(typeDesc);
* JIPointer ptrToArrayDesc = new JIPointer(arrayDesc);
* forTypeDesc.addMember(TypeDesc.VT_PTR,ptrToTypeDesc);
* forTypeDesc.addMember(TypeDesc.VT_SAFEARRAY,ptrToTypeDesc);
* forTypeDesc.addMember(TypeDesc.VT_CARRAY,ptrToArrayDesc);
* forTypeDesc.addMember(TypeDesc.VT_USERDEFINED,Integer.class);
*
*
*
* The TypeDesc.VT_PTR is an Integer and is used as a discriminant
* to select ptrTypeDesc, TypeDesc.VT_CARRAY chooses ptrArrayDesc.
*
*
*
* @since 1.0
*/
public final class JIUnion implements Serializable {
private static final long serialVersionUID = -3353313619137076876L;
private HashMap dsVsMember = new HashMap();
private Class discriminantClass = null;
//private int length = 0;
//private int lengthOfDisc = 0;
//private Union clone = null;
private JIUnion() {
}
/**
* Creates an object with discriminant type specified. Used only during
* deserializing the union. Can only be of the type
* Integer,Short,Boolean or
* Character.
*
* @param discriminantClass
* @throws IllegalArgumentException if the discriminantClass is
* not of the type as specified above.
*/
public JIUnion(Class discriminantClass) {
//the discriminant can only be a int, boolean or char
if (!discriminantClass.equals(Integer.class) && !discriminantClass.equals(Short.class)
&& !discriminantClass.equals(Boolean.class) && !discriminantClass.equals(Character.class)) {
//has to be from one of these. Rule from IDL.
throw new IllegalArgumentException(JISystem.getLocalizedMessage(JIErrorCodes.JI_UNION_INCORRECT_DISC));
}
this.discriminantClass = discriminantClass;
}
/**
* Adds a member to this Union. The member is distinguished
* using the discriminant.
*
* @param discriminant
* @param member
* @throws JIException
* @throws IllegalArgumentException if any parameter is null
*/
public void addMember(Object discriminant, Object member) throws JIException {
if (discriminant == null || member == null) {
throw new IllegalArgumentException(JISystem.getLocalizedMessage(JIErrorCodes.JI_UNION_NULL_DISCRMINANT));
}
if (!discriminant.getClass().equals(discriminantClass)) {
throw new JIException(JIErrorCodes.JI_UNION_DISCRMINANT_MISMATCH);
}
if (member.getClass().equals(JIPointer.class) && !((JIPointer) member).isReference()) {
((JIPointer) member).setDeffered(true);
} else if (member.getClass().equals(JIString.class)) {
((JIString) member).setDeffered(true);
}
dsVsMember.put(discriminant, member);
}
/**
* Adds a member to this Union. The member is distinguished
* using the discriminant.
*
* @param discriminant
* @param member
* @throws JIException
* @throws IllegalArgumentException if discriminant is
* null
*/
//used both for reading and writing
public void addMember(Object discriminant, JIStruct member) throws JIException {
if (discriminant == null) {
throw new IllegalArgumentException(JISystem.getLocalizedMessage(JIErrorCodes.JI_UNION_NULL_DISCRMINANT));
}
if (!discriminant.getClass().equals(discriminantClass)) {
throw new JIException(JIErrorCodes.JI_UNION_DISCRMINANT_MISMATCH);
}
if (member == null) {
member = JIStruct.MEMBER_IS_EMPTY;
}
dsVsMember.put(discriminant, member);
//do not need a seperate list of pointers like the struct , since based on the discriminant only 1 pointer
//(if present) can be deserialized\serialized.
}
/**
* Removes the entry , identified by it's discriminant from the
* parameter list of the union.
*
* @param discriminant
*/
public void removeMember(Object discriminant) {
dsVsMember.remove(discriminant);
}
/**
* Returns the discriminant Vs there members Map.
*
* @return
*/
public Map getMembers() {
return dsVsMember;
}
void encode(NetworkDataRepresentation ndr, List listOfDefferedPointers, int FLAGS) {
if (dsVsMember.isEmpty() || dsVsMember.size() > 1) {
throw new JIRuntimeException(JIErrorCodes.JI_UNION_DISCRMINANT_SERIALIZATION_ERROR);
}
//first write the discriminant and then the member
Iterator keys = dsVsMember.keySet().iterator();
JIMarshalUnMarshalHelper.serialize(ndr, discriminantClass, keys.next(), listOfDefferedPointers, FLAGS);
keys = dsVsMember.values().iterator();
Object value = keys.next();
//will not write empty union members
if (!value.equals(JIStruct.MEMBER_IS_EMPTY)) {
JIMarshalUnMarshalHelper.serialize(ndr, value.getClass(), value, listOfDefferedPointers, FLAGS);
}
}
JIUnion decode(NetworkDataRepresentation ndr, List listOfDefferedPointers, int FLAGS, Map additionalData) {
//first read discriminant, and then call the appropriate deserializer of the member
if (dsVsMember.isEmpty()) {
throw new JIRuntimeException(JIErrorCodes.JI_UNION_DISCRMINANT_DESERIALIZATION_ERROR);
}
//shallowClone();
//first write the discriminant and then the member
JIUnion retVal = new JIUnion();
retVal.discriminantClass = discriminantClass;
Object key = JIMarshalUnMarshalHelper.deSerialize(ndr, discriminantClass, listOfDefferedPointers, FLAGS, additionalData);
//next thing to be deserialized is the member
Object value = dsVsMember.get(key);
//should allow null since this could be a "default"
if (value == null) {
value = JIStruct.MEMBER_IS_EMPTY;
}
//will not write empty union members
if (!value.equals(JIStruct.MEMBER_IS_EMPTY)) {
retVal.dsVsMember.put(key, JIMarshalUnMarshalHelper.deSerialize(ndr, value, listOfDefferedPointers, FLAGS, additionalData));
} else {
retVal.dsVsMember.put(key, value);
}
return retVal;
}
int getLength() {
int length = 0;
Iterator itr = dsVsMember.keySet().iterator();
while (itr.hasNext()) {
Object o = itr.next();
int temp = JIMarshalUnMarshalHelper.getLengthInBytes(o.getClass(), o, JIFlags.FLAG_NULL);
length = length > temp ? length : temp; //length of the largest member
}
return length + JIMarshalUnMarshalHelper.getLengthInBytes(discriminantClass, null, JIFlags.FLAG_NULL);
}
int getAlignment() {
int alignment = 0;
if (discriminantClass.equals(Integer.class)) {
//align with 4 bytes
alignment = 4;
} else if (discriminantClass.equals(Short.class)) {
//align with 2
alignment = 2;
}
return alignment;
}
// public String toString()
// {
// return "[" + dsVsMember + "]";
// }
}