sorting - Java - Sort Alphabetically as well as collate unique elements together -

i have array list filled objects each have info them. example :

{term(c,2), term(h,2), term(c,1), term(o,3)} 

the goal right change arraylist result such :

{term(c,3), term(h,2), term(o,3)} 

we want collate terms together. have following @ stage.

char element = 'a'; int amt_atom = 0; int index = 0;  char alphabet = 'a'; char alpha = 'a';  (; alpha <= 'z' ; alpha++){     search:     ( ; alphabet <= 'z' ; alphabet++ ) {         ( int = 0 ; < terms.size() ; i++){             if ( terms.get(i).getelement() == alphabet){                 element = terms.get(i).getelement();                 amt_atom = terms.get(i).getatoms();                 index = i;                   system.out.println(element + " , " + amt_atom + " , " + index );                 alphabet++;                 break search;             }         }     }      (int = 0 ; < terms.size() ; i++){         if ( terms.get(i).getelement() == element && != index){             int amt_atoms2 = terms.get(i).getatoms();             terms.set(index, new term ( element, amt_atom + amt_atoms2 ));             terms.remove(i);         }     } } 

also, array given might not alphabetic , must put in alphabetic order. example be: ch3ch2ch2ch2ch2ch3 , result = c6h14.

edit : sorry, should have specified wrong original code. so, doing c2h2ho3 results in c2h3o3which fantastic because right when try ch3ch2ch2ch2ch2ch3 c2h5 not @ correct. not sure why .

am on right track? maybe tell me doing wrong? new java , therefore have extremely basic knowledge if can explain while using structures , elements of java might have used above. thanks

how first sort, collate? make term's implement comparable interface , call terms.sort();. go on list , collate, easier once it's sorted.

don't worry performance here. should fast.