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I just able to load songs from sdcard and get a list of their albums but it contains duplicates in it. How to remove duplicated from my album list. My Album list is a type of ArrayList and Album class contains two String variable in it. thank you for your help.

Mayur Kharche
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  • possible duplicate of [How do I remove repeated elements from ArrayList?](http://stackoverflow.com/questions/203984/how-do-i-remove-repeated-elements-from-arraylist) – Selvin Aug 03 '15 at 13:39
  • ... and of course ... it will not work ... obviously, it need one more thing ... something that would compare the items ... – Selvin Aug 03 '15 at 13:40
  • It,s not a duplicate of that question. I can remove elements from ArrayList of predefined classes but my question is to make my list unique using custom class which contain more than one variables. – Mayur Kharche Aug 03 '15 at 15:28
  • It is a duplicate ... but still you should know how Set compare the objects ... so take a look @petey answer ... – Selvin Aug 03 '15 at 15:34

1 Answers1

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For your Custom class, add an equals and hashCode method, 

public static class Custom
{
    public final String item1;
    public final String item2;
    public Custom(String i1, String i2) {
        item1 = i1;
        item2 = i2;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        Custom custom = (Custom) o;

        if (!item1.equals(custom.item1)) {
            return false;
        }
        if (!item2.equals(custom.item2)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        int result = item1.hashCode();
        result = 31 * result + item2.hashCode();
        return result;
    }

}

Then before adding, check that the Arraylist does not contain a Custom before adding. 

final ArrayList<Custom> customs = new ArrayList<Custom>();
Custom one = new Custom("aa", "bb");
Custom two = new Custom("aa", "bb");

if (!customs.contains(one)) {
    arraylist.add(one);
}

if (!customs.contains(two)) {
    arraylist.add(two);
}
petey
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