Is there a cleaner way for doing this ? 

```
public void change(char x)
{
    if(x == 'a')
    {
       return 'b';
    }
    else if(x == 'b')
    {
       return 'a';
    }
    else if(x == 't')
    {
       return 'r';
    }
    else if(x == 'r')
    {
       return 't';
    }
    return 'z';
}

```

I was wondering if there was anything built into Java so that I can swap pairs of characters like a dictionary in Python or is this the best way to do this?