Java Compare Two List's object values?

I have two list **ListA<MyData> listA = new ArrayList<MyData>()** and ListB<MyData> listB = new ArrayList<MyData>() both contain object of type MyData and MyData contain these variables.

MyData {
    String name;
    boolean check;
} 

ListA and ListB both contains MyData objects ,now I have to compare both the list's object values here name as well check variable like if ListA contains these object values

ListA = ["Ram",true],["Hariom",true],["Shiv",true];

and ListB also contain

ListB = ["Ram",true],["Hariom",true],["Shiv",true];

then i have to compare lists and return false because both list are same But if ListA contains

ListA = ["Ram",true],["Hariom",true],["Shiv",false];

and ListB Contain

 ListB = ["Ram",true],["Hariom",true],["Shiv",true];

then I have to compare lists and return true because both list are not same

or vice-versa so any slight change in the any list values I have to return true. One thing I have to mentioned here objects can be in any order.

Solution 1:

It's not the most efficient solution but the most terse code would be:

boolean equalLists = listA.size() == listB.size() && listA.containsAll(listB);

Update:

@WesleyPorter is right. The solution above will not work if duplicate objects are in the collection.
For a complete solution you need to iterate over a collection so duplicate objects are handled correctly.

private static boolean cmp( List<?> l1, List<?> l2 ) {
    // make a copy of the list so the original list is not changed, and remove() is supported
    ArrayList<?> cp = new ArrayList<>( l1 );
    for ( Object o : l2 ) {
        if ( !cp.remove( o ) ) {
            return false;
        }
    }
    return cp.isEmpty();
}

Update 28-Oct-2014:

@RoeeGavriel is right. The return statement needs to be conditional. The code above is updated.

Solution 2:

ArrayList already have support for this, with the equals method. Quoting the docs

... In other words, two lists are defined to be equal if they contain the same elements in the same order.

It does require you to properly implement equals in your MyData class.

Edit

You have updated the question stating that the lists could have different orders. In that case, sort your list first, and then apply equals.

Solution 3:

I got this solution for above problem

public boolean compareLists(List<MyData> prevList, List<MyData> modelList) {
        if (prevList.size() == modelList.size()) {
            for (MyData modelListdata : modelList) {
                for (MyData prevListdata : prevList) {
                    if (prevListdata.getName().equals(modelListdata.getName())
                            && prevListdata.isCheck() != modelListdata.isCheck()) {
                        return  true;

                    }
                }

            }
        }
        else{
            return true;
        }
        return false; 

    }

EDITED:-
How can we cover this... Imagine if you had two arrays "A",true "B",true "C",true and "A",true "B",true "D",true. Even though array one has C and array two has D there's no check that will catch that(Mentioned by @Patashu)..SO for that i have made below changes.

public boolean compareLists(List<MyData> prevList, List<MyData> modelList) {
        if (prevList!= null && modelList!=null && prevList.size() == modelList.size()) {
            boolean indicator = false;
            for (MyData modelListdata : modelList) {
                for (MyData prevListdata : prevList) {
                    if (prevListdata.getName().equals(modelListdata.getName())
                            && prevListdata.isCheck() != modelListdata.isCheck()) {
                        return  true;

                    }
                    if (modelListdata.getName().equals(prevListdata.getName())) {
                        indicator = false;
                        break;
                    } else
                        indicator = true;
                }
                }

            }
        if (indicator)
            return true;
    }
        }
        else{
            return true;
        }
        return false; 

    }

Solution 4:

First, implement the MyData.equals(Object o) and MyData.hashCode() methods. Once you implemented the equals method, you can iterate over the lists as follows:

if(ListA == null && ListB == null)
    return false;
if(ListA == null && ListB != null)
    return true;
if(ListA != null && ListB == null)
    return true;
int max = ListA.size() > ListB.size() ? ListA.size() : ListB.size();
for(int i = 0; i < max; i++) {
    myData1 = ListA.get(i);
    myData2 = ListB.get(i);
    if(!myData1.equals(myData2)) {
        return true;
    }
}
return false;

Solution 5:

I found a very basic example of List comparison at List Compare This example verifies the size first and then checks the availability of the particular element of one list in another.