java - Which strategy to use? Object Clone or a simple Map -

i need something. code of following template. assume customobject has multiple property1, property2, ..property100.

list<customobject> customobjectlist = /*<method call external api returns said list >*/ if(customobjectlist != null && customobjectlist.size() > 0){     //*** point ***<clone object>     resultlist = <some method process above list>(customobjectlist)      if(resultlist.size() > 0){         for(iterator<map.entry<customobject, externalresponse>> itr = resultlist.entryset().iterator(); itr.hasnext();) {             //code modifies properties in customobjects             //*** point b ***resetaproperty(<object clone>)         }     } } 

at point b, need 1 unmodified specific property of original object use in method. have 2 strategies this:

1. clone object @ point a, , use cloned copy property shown in above code. @ point a, use loop , a
2. map form associate array of object names, property original values , traverse them property initial value @ point b

avoid cloning because requires deep cloning

.clone() on list end in tears because have deep clone objects in list, referenced objects, , on.

deep cloning means have make binary copy of every last object in object graph. copying reference give shallow copy , see changes made referenced object. miss 1 property , have hell of time finding bug.

solution

what should make customobject instances immutable , don't need worry versioning, can never change, mutation involve creating new instance immutable , complete different object. never had worry versions.

of course instance variables point other objects need immutable well. same problem deep clone taking angle. more manageable angle.