Get data from ArrayList inside method

Question

I have an ArrayList item that holds Objects

ArrayList<Object> nodeList;

I fill it with records I retrieve form database like this

//start loop
nodeList.add(getResultSet().getString(i).trim());
//end loop

Now, I want to get those results, so I create a "getter" method

public Object getResults(){
    for(int i = 0; i < nodeList.size(); i++){
        return nodeList.get(i);
    }
}

Netbeans tells me that return statement is missing, although I return every single object of the arrayList inside loop. How am I supposed to fix it? I tried to return an Array of Objects but it didn't work either. It's still in a loop an it wants to return something outside loop. Thank you in advance.

What if nodeList.size() returns 0? Then the for loop will never run and nothing will be returned so you need a return statement after the for loop — usama8800
– usama8800, Commented Jul 4, 2014 at 19:20
The method will return just the first object and not the others. — usama8800
– usama8800, Commented Jul 4, 2014 at 19:21
If you're only storing Strings in your List, then change the type declaration to List<String> instead. — Luiggi Mendoza
– Luiggi Mendoza, Commented Jul 4, 2014 at 19:26
@LuiggiMendoza Actually I want to use it for every type of data -String, int etc. What if I cast that objects? — Vassilis De
– Vassilis De, Commented Jul 4, 2014 at 19:31
You should not store the data in a List<Object>, instead create an entity with the desired fields and fill each field in a class instance. — Luiggi Mendoza
– Luiggi Mendoza, Commented Jul 4, 2014 at 19:33

M A · Accepted Answer · 2014-07-06 10:49:25Z

4

Netbeans is complaining because, if the list is empty, the code will not enter the for loop body and no value is ever returned.

Also your getter method makes no sense. You are always returning the first element in the list because return will exit the method. If you "want to get those results", you should just return the whole nodeList.

public List<Object> getResults() {
   return nodeList;
}

If you want to get element at index i, you would write the getter as follows:

public Object getResult(int i) {
   return nodeList.get(i);
}

Also, as pointed out by Luiggi in comments, you could avoid adding the results in a list of Objects and instead create an entity class with fields corresponding to the retrieved columns.

edited Jul 6, 2014 at 10:49

answered Jul 4, 2014 at 19:22

M A

73.2k14 gold badges149 silver badges182 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Vassilis De Over a year ago

manouti & @Evgeny Makarov thank you so much about your solution. It works now and I get data the way I wanted.

Evgeny Makarov · Accepted Answer · 2014-07-04 19:22:06Z

2

Once you get to return command, method finished. You getting error because in case you will provide empty list as method argument, the for loop will be ignored and method should return something in this case.

If you want to return some value from list, you should write something like:

public Object getResults(int position){
        return nodeList.get(position);
}

answered Jul 4, 2014 at 19:22

Evgeny Makarov

1,4581 gold badge22 silver badges44 bronze badges

Collectives™ on Stack Overflow

Get data from ArrayList inside method

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related