Merge two object lists in java of the same type

Question

How do i merge two object lists in java for eg: i have 2 lists listA listB with one object each like listA[name=abc,age=56, weight=null] listB[name=Null,age=Null,weight=70]

Expected result= Output[name=abc,age=56, weight=70]

Answer 1

Sorry, read your question wrong the first time.

Here's the process you want to follow (the question is a bit unclear so I'm assuming that whether a property is null or not is an exclusive thing - for example, if A has null weight then B MUST have a non-null weight).

1. Loop through your lists ONCE.

2. Within each iteration, create a new object. Then check each property of the object in List A - if it's null, then add the corresponding property from B.

3. Add new object to list.

4. Continue iterating

List<Object> newList = new ArrayList<Object>();
for (int i = 0; i < listA.size(); i++) {
    Object newObject = new Object();
    Object objectA = listA.get(i);
    if (objectA.getProperty1() == null) {
       newObject.setProperty1(listB.get(i).getProperty1());
    }
    // repeat this with your other properties
    newList.add(newObject);
}