```
 @RequestMapping(value="/portfolios", method = RequestMethod.GET)
    public @ResponseBody List<PortfolioVO>  getPortfolios(HttpServletRequest request, @RequestParam(required= false) String region) {
List<PortfolioVO> portfolios = gmiCacheService.getPortoliosForRegion(user, region);

        return portfolios;      
    }

```

I have another List from another function that I need to add.

to then just return portfolios. I am very new to Java and do not know how to implement this.
['https://Stackoverflow.com/questions/42236697', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/7470849/']
In c#, I would use `Tuple` for storing those two list separately. But in Java, I didn't get similar data structure. But you can make your custom tuple structure. 

[From this answer](https://stackoverflow.com/questions/2670982/using-pairs-or-2-tuples-in-java) : 

```
public class Tuple<X, Y> { 
  public final X x; 
  public final Y y; 
  public Tuple(X x, Y y) { 
    this.x = x; 
    this.y = y; 
  } 
}

```

Using above structure, you can store two different list and use it.

If you are allowed to use third party library, you can have [javatuples](http://www.javatuples.org/) where you can use `Pair` structure
I see two ways:

1) return array of lists: `public @ResponseBody List[]<PortfolioVO> getPortfolios( ... )`

inside it: `return new List[] { list1, list2 };`

This is fast to implement, but it is not nice and little bit dirty.

2) More proper way, I think, create class for this case:

```
static class ListPairHolder {
    List<PortfolioVO> list1;
    List<PortfolioVO> list2;

    ListPairHolder(List<PortfolioVO> list1, List<PortfolioVO> list2){
       this.list1 = list1; this.list2 = list2;
    }
}

```

and return this type from method.