Map<String, Integer> stringsWithCount = new TreeMap<String,Integer>();
                        for (Message msg : convInfo.messages) {
                            // where ever your input comes from: turn it into lower case,
                            // so that "ccc" and "CCC" go for the same counter
                            String item = msg.userName;
                            if (stringsWithCount.containsKey(item)) {
                                stringsWithCount.put(item, stringsWithCount.get(item) + 1);
                            } else {
                                stringsWithCount.put(item, 1);
                            }
                        }

for (Entry<String, Integer> entry : stringsWithCount.entrySet()) {

  System.out.println(entry.getKey()+"("+entry.getValue()+")");
                        }

G_LO(1)
FCHAN95(1)
G_LO(1)
FCHAN95(2)
G_LO(1)
FCHAN95(2)
G_LO(1)
WVU(1)
FCHAN95(2)
G_LO(1)
SWONG00(1)
WVU(1)
FCHAN95(3)
G_LO(1)
SWONG00(1)
WVU(1)
FCHAN95(4)
G_LO(1)
SWONG00(1)
WVU(1)
FCHAN95(5)
G_LO(1)
SWONG00(1)
WVU(1)
FCHAN95(6)
G_LO(1)
SWONG00(1)
WVU(1)