how to combine between two arraylist if has same value

[Mobio Dev]

hi, i have 2 arraylist as below

al1 - [Consignment, Bank, Custodian, Rejected, Bank]
al2 - [[2, 0, 0, 0, 0, 0, 0], [6, 0, 0, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0, 0], [4, 0, 0, 0, 0, 0, 0], [0, 1, 0, 0, 0, 0, 0]]

so my case is i have to check al1 there is any duplicate value, if have have combine the value in al2

so expected result is

al1 - [Consignment, Bank, Custodian, Rejected]
al2 - [[2, 0, 0, 0, 0, 0, 0], [6, 1, 0, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0, 0], [4, 0, 0, 0, 0, 0, 0]]

i'm trying to get solution by googling, anyhow how this can be done

thanks in advance

[John Jai]

Lists should allow duplicates. You should use Set if you want to remove duplicates.

One way of removing the duplicates is to form a Set object from your List and converting it back to List like below...

nameList = new ArrayList<String>( new HashSet<String>(nameList));

[fred rosenberger]

maintaining data in two parallel arrays is a nightmare. You'd do better by making a single object that can store both the String and the array associated with it. Then you could possibly store them in a map, using the String as the key. First check to see if it is already in the collection, and if so, 'combine' your arrays. If not, simply add it in.

[Mobio Dev]

i found solution as below

for(int i=0;i<al1.size();i++){
for(int j = al1.size()-1; j > i; j--) {
if(al1.get(i).equals(al1.get(j))){
ArrayList temp1 = (ArrayList)al4.get(i);
ArrayList temp2 = (ArrayList)al4.get(j);
for(int k=0;k<temp1.size();k++){
if(!temp2.get(k).equals("0")){
temp1.set(k, temp2.get(k));
}
}
al1.remove(j);
al4.remove(j);
al4.set(i, temp1);
}
}
}